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Effects of omega-3 supplementation in combination with diet and exercise on weight loss and body composition
Abstract
In addition to the metabolic and cardiovascular benefits of omega-3 (n-3) fatty acids, several studies have suggested an added weight loss-enhancing benefit to this supplement.
The objective was to assess whether supplemental omega-3 fatty acids in conjunction with diet and exercise augment weight loss over a 6-mo period.
In a single-institution, placebo-controlled, randomized clinical trial, 128 individuals with a body mass index (in kg/m(2)) between 26 and 40 were assigned to receive 5 omega-3 [3.0 g eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) at a 5:1 ratio (EPA:DHA)] or placebo capsules daily in conjunction with lifestyle modification. The primary endpoint was weight loss; secondary endpoints included metabolic and psychometric variables. Analyses were by intention-to-treat.
Overweight and obese individuals were assigned to the omega-3 arm (n = 64) or to the placebo arm (n = 64). Subjects in both arms received dietary and exercise counseling. Eighty-one individuals completed the 24-wk study, and the dropout rate was 27%. Subjects in both arms lost an average of >5% of their body weight. No significant differences in weight loss were observed between the omega-3 (-5.2 kg; 95% CI: -6.0, -4.4 kg) and placebo (-5.8 kg; 95% CI: -6.7, -5.1 kg) arms. The absolute mean (±SEM) change difference was 0.61 ± 0.58 kg (P = 0.29). In addition, no significant differences in the other factors assessed were observed.
Omega-3 fatty acids were not effective as an adjunct for weight loss in this otherwise healthy, overweight population.
... 2016). Research has shown that inclusion of omega-3 fatty acids as feed supplements in the diets of animals and humans supports the reduction of accumulation of fats in the tissues (Hill, Buckley, Murphy, & Howe, 2007;Rossmeisl et al., 2009, & Go et al., 2016 whereas some studies totally countered its significant role in influencing lipolysis (Buckley & Howe, 2009;DeFina et al., 2011;Castilho, Antônio Carlos, & de Souza, 2015). Omega-3 fatty acids' anti-obesity beneficial effects include enhanced adipocyte apoptosis, improved plasma adiponectin levels, reduced visceral fats deposition, enhanced lipid profile and decreased body fat accumulation, exerting an anti-inflammatory effect in peripheral tissues (Du, Jin, Fang & Su, 2015;de Mello et al., 2018). ...
... In this present study, we observed a slight drop in weight gain of both male and female rats fed with the tested diets of O3FA supplementation when compared with the control, with the change recording no statistical Go et al. (2016). DeFina et al. (2011) reported no significant weight loss effect in overweight and obese patients with the introduction of omega-3 fatty acid supplementation in conjunction with physical activity. In an attempt to explain the various effects of O3FAs on the body weight as observed in this study, we report that a non-significant increase in body weight could depict that administration of O3FAs initiated an action whereby the anabolic effects synergised with the catabolic one in protecting against excessive body fat deposition. ...
... The Journal of Basic and Applied Zoology significant difference. The observed non-significant effect (p > 0.05) in the body weight of treated male and female rats compared with the control in the present study is in consonants withDeFina et al. (2011) andCastilho, Antônio Carlos, &de Souza (2015) but varies with ...
Background
Omega-3 fatty acids’ inclusion as feed supplement in the diets of both human and animals has been found to play a significant role in body metabolism. The aim of this present study was to evaluate the effects of graded doses of omega-3 fatty acids on haematology and body weight of adult male and female Rattus norvegicus (Wistar albino rats) as a model animal.
Methods
A total of seventy-two adult male and female albino rats were randomly assigned into two experimental units. Each unit was grouped into three and received different treatment diets. Blood erythrocytes and weight were sampled on days 0, 14 and 28 to evaluate haematological parameters and body weight.
Results
Results showed concentration- and time-dependent significant increases ( p < 0.05) in the packed cell volume (PCV), haemoglobin (Hb), white blood cells (WBCs), mean cell volume (MCV) and mean cell haemoglobin (MCH) and non-significant change ( p > 0.05) in the red blood cells (RBCs) and mean cell haemoglobin concentration (MCHC) in male rats after day 0. In female rats, significant increases ( p < 0.05) were recorded in the PCV, Hb, MCV and MCH, whereas no significant increase was observed in the RBCs. Activities of WBCs and MCHC showed mixed trend in female rats. The results of the body weight recorded non-significant increases ( p > 0.05) in both experimental units.
Conclusion
Our findings depict that the use of omega-3 fatty acids in the diets of both male and female rats produced a dose-dependent effect on blood formation while its role in controlling weight gain was observed. Hence, its intake in both animal and human diets should be rightly prescribed.
... Of 140 items that were evaluated among all studies, 25% were classified as unclear because the authors did not provide enough data to analyze some essential items of the design. Two studies had four out of seven items classified as unclear risk [29,36]. The item with the highest risk of bias was item 5 (incomplete outcome data), in which 13 of the 20 studies were classified as high risk of bias [15e17, 21,22,27,28,30,33e37]. ...
... In contrast, another group consumed 1.5 g per day and showed significant weight loss [37]. Also, there seems to be no relation to the study duration since the longest study (24 weeks) did not find significant results [36]. In contrast, another study that lasted only three weeks found an effect on weight loss [29]. ...
Background
Omega-3 is a supplement that promotes several health benefits. The evidence on omega-3 in weight loss or body fat mass is inconclusive. This study aimed to review the literature on studies that evaluated the effect of omega-3 supplementation and changes in weight and/or body fat mass in humans.
Methods
A systematic review, following the recommendations of PRISMA, in the databases Pubmed, Lilacs, and Scielo. Only experimental studies in humans that evaluated the effects of supplementation with omega-3 on weight loss and/or body fat mass were included.
Results
In total, 20 studies were selected, of which 11 found no effect, and the other nine find some benefits. Two studies found a reduction in individuals' body fat, and a third found these results in women and a fourth only in men. In children and adolescents, one study found a difference in weight loss between groups. Four studies reported decreased body weight in women, and in men, only one found this result.
Conclusion
To date, there is no consistency in the literature that omega-3 has benefits in weight loss or body fat mass in humans. Due to the studies' heterogeneity and inconsistency in the results, further studies on the subject are necessary.
... To date, few observational studies [13,14] and RCTs (total n = 417) [19][20][21][22][23][24] have examined the associations of circulating or supplemental n-3 PUFAs levels with wellassessed body fat and fat distribution. Compared with anthropometric indices, DXA-derived body fat indices can measure total and regional FM directly and precisely. ...
... cohort [15][16][17]) studies, in studies using DXA-derived body fat (vs. anthropometric indices) [19,[21][22][23], in studies with objectively assessed n-3 PUFAs (vs. dietary FA assessments) [16], and in RCTs [18] (vs. ...
Previous studies have reported that high-dose supplementation of n-3 polyunsaturated fatty acids (PUFAs) may reduce the risk of metabolic diseases, but there is limited evidence of an effect on body fat. We examined the associations of erythrocyte n-3 PUFAs with body fat and fat distribution in a general population consuming a normal diet.
This community-based cross-sectional study included 3075 Chinese (68% women, 40–75 years) recruited between 2008 and 2013. We collected general information and measured anthropometric indices; erythrocyte n-3 PUFAs (including α-C18:3, C20:5, C22:5 and C22:6) by gas-chromatography, and fat mass (FM) and %FM at the total body (TB), android (A) and gynoid (G) regions by dual-energy X-ray absorptiometry (DXA).
Both minimally and maximally adjusted models showed dose-dependent inverse associations of total and individual levels of erythrocyte n-3 PUFAs (except C20:5 n-3[EPA]) with adiposity indices. In the full model, the mean differences between quartiles 4 and 1 of total n-3 PUFAs were −1.60% (BMI), −4.06% (TB FM), −5.38% (A FM), −2.05% (G FM), −2.05% (TB %FM), −3.39% (A %FM) and −2.50% (% A/G); the ORs (95% CI) of %FM-derived obesity (≥25% for men, ≥35% for women) for the highest (vs. lowest) quartile were 0.70 (0.57, 0.86) for total n-3 PUFAs and 0.71 (0.58, 0.87), 0.96(0.78, 1.18), 0.82(0.67, 1.00), 0.66 (0.54, 0.81) for α-C18:3/C20:5/C22:5/C22:6 n-3, respectively. The favourable associations were more pronounced for the DXA-derived FM indices, measurements at the android region and for C22:6 n-3. No significant associations between C20:5 n-3 and the adiposity indices were observed.
Higher levels of circulating n-3 PUFAs were dose-dependently associated with better profiles of body fat and fat distribution, particularly in the abdominal regions in this population.
... Flaxseed has been described as a functional food containing high amounts of polyunsaturated fatty acids, mainly α-linolenic acid (ALA), a n-3 fatty acid, as well as soluble fiber, and lignin precursors [11,12]; it has hypolipidemic, anti-inflammatory, and antioxidant properties which can enhance satiety [13][14][15]. Its high content of polyunsaturated fatty acids, fiber and lignan can assist in weight management and decrease appetite, inflammation and hyperlipidemia [12][13][14][16][17][18][19]. Experimental and human studies have demonstrated that flaxseed supplementation can reduce serum triglyceride, total cholesterol, inflammatory markers, and blood pressure [20][21][22][23]. ...
... Barre et al have reported that consumption of flaxseed lignin for 3 months induced better waist circumference management in diabetic patients [30]. These effects can be due to the high n-3 fatty acids content of flaxseed [16,18,31,32], and its high dietary fiber content [33,34], which both of them have beneficial effects on weight reduction [35,36]. Dietary fiber can reduce appetite, energy intake and bodyweight [19]. ...
Background:
The aim of this study was to assess the effects of supplementation with flaxseed on anthropometric measurements, lipid profile, insulin resistance, and inflammatory biomarkers in overweight and obese adults.
Methods:
Fifty overweight and obese adults with body mass index (BMI) of 30.72 ± 3.31 kg/m2 participated in this study. Participants were randomly assigned to take lifestyle advice or lifestyle advice plus 30 g/day milled flaxseed for 12 weeks. The primary outcome was body weight; secondary outcomes included other anthropometric parameters, lipid profile and inflammatory biomarkers.
Results:
At the end of the study, the following significant mean differences were seen in flaxseed and control groups, respectively: weight [-9.36 vs. -3.09 kg; P < 0.001], BMI [-3.34 vs. -1.2 kg/m2; P < 0.001], triglyceride [-62.88 vs. -9.85 mg/dL; P < 0.001], total cholesterol [-32.2 vs. -14.95; P = 0.04], homeostatic model assessment (HOMA-IR) [1.25 vs. -0.32; P = 0.024], high sensitive- C reactive protein [-2.2 vs. -1.01 mmol/L; P < 0.001] and tumor necrosis factor-α [-1.34 vs. -0.14 Pg/mL; P = 0.005].
Conclusion:
These results suggest that flaxseed supplementation in addition to lifestyle modification is significantly superior to lifestyle modification alone for weight loss. More studies with different dosages of flaxseed are needed to find the optimal dosage. This trial was registered at clinicaltrials.gov as NCT02410668.
... 5 The ratio of omega-3 and omega-6 fatty acids was also considered, because these fatty acids influence the metabolic pathways of each other. 10 Intervention with supplementation of omega-3 alone or combined with omega-6 in certain doses, with or without dietary intervention, was demonstrated to exert bodyweight-loss-related effects [11][12][13][14][15][16] such as in decreasing body fat mass [11][12][13] and hip circumference losses. 15 However, studies on dietary intervention alone focusing on omega-3 and omega-6 that have investigated the body weight lossrelated effects is lacking. ...
... Although many intervention studies have used fish oil supplements to demonstrate significant reductions in body weight, [11][12][13][14][15][16]31 only a few studies have employed the dietary intervention approach; however, they have not specifically reported its effect in body weight reduction or the information of the confirmed ratio of these fatty acid. Hence, the optimised diet developed in our study applied a cut off value of <10 for the omega-6/omega-3 ratio, which was obtained by calculating the omega-6 and omega-3 RDA requirements for Indonesian children aged 1-3 years. ...
Background and objectives:
Diets with a specific omega-6/omega-3 fatty acid ratio have been reported to have favourable effects in controlling obesity in adults. However, development a local-based diet by considering the ratio of these fatty acids for improving the nutritional status of overweight and obese children is lacking. Therefore, using linear programming, we developed an affordable optimised diet focusing on the ratio of omega- 6/omega-3 fatty acid intake for obese children aged 12-23 months.
Methods and study design:
A crosssectional study was conducted in two subdistricts of East Jakarta involving 42 normal-weight and 29 overweight and obese children, grouped on the basis of their body mass index for-age Z scores and selected through multistage random sampling. A 24-h recall was performed for 3-nonconsecutive days to assess the children's dietary intake levels and food patterns. We conducted group and structured interviews as well as market surveys to identify food availability, accessibility and affordability.
Results:
Three types of affordable optimised 7-day diet meal plans were developed on the basis of breastfeeding status. The optimised diet plan fulfilled energy and macronutrient intake requirements within the acceptable macronutrient distribution range. The omega-6/omega-3 fatty acid ratio in the children was between 4 and 10. Moreover, the micronutrient intake level was within the range of the recommended daily allowance or estimated average recommendation and tolerable upper intake level.
Conclusions:
The optimisation model used in this study provides a mathematical solution for economical diet meal plans that approximate the nutrient requirements for overweight and obese children.
... [6] All this time omega-PUFAs albeit vitamin E, which functions in lipid metabolism and metabolismrelated oxidative stress regulators, are crucial players in liver health management as a whole. [7] The deficiency or imbalance of it may accelerate the development of fatty liver diseases such as steatosis and inflammation. [8] Resmetirom, also referred to as Rezdiffra, is a novel drug for MASLD that selectively agonists thyroid hormone receptor-beta (THR-β). ...
... Human studies have some conflicting outcomes. DeFina et al. (48) studied the effects of omega-3 PUFAs on body weight loss in 81 obese or overweight subjects for a period of 6 months. No significant difference was observed in body weight between the omega-3 and placebo groups. ...
Objective:
omega-3 polyunsaturated fatty acids (PUFAs) are important nutrients that play role in obesity, body lipids, inflammation, and neural function. There is controversy in studies on the effect of omega-3 PUFA supplementation on weight loss and cognitive function. The aim of this study was to investigate the effect of omega-3 PUFA supplementation on weight loss and cognitive function in obese or overweight adults on a weight loss diet.
Methods:
40 adult volunteers aged 30-60 years, with body mass index (BMI) between 27.0 and 35.0 kg/m2, were randomly allocated into two groups. All subjects were involved in a weight loss diet program. The subjects in the omega-3 group (n = 20) also received daily supplementation with 1020 mg of omega-3 PUFAs (580 mg eicosapentaenoic acid (EPA), 390 mg docosahexaenoic acid (DHA), 50 mg other omega-3 PUFAs) for 12 weeks. Anthropometric measurements and body composition analysis were obtained at onset and at weeks 4, 8, and 12 of the study. The Montreal Cognitive Assessment (MoCA) test was used for evaluating cognitive functions at diet onset and at the end of week 12.
Results:
significant decreases were observed in weight, waist, and BMI in both groups. Abdominal fat mass and percentage decreased more in the omega-3 group than in the control group (p ≤ 0.05). MoCA scores increased in both groups within time, without statistical significance between groups.
Conclusion:
omega-3 PUFA supplementation augmented the reduction of abdominal fat mass and percentage in overweight or obese individuals on a weight loss diet. Further studies are required to identify the relationship and mechanisms of action of omega-3 PUFA supplementation on cognitive performance and weight loss.
... On the other hand, Gammelmarka et al. [33] in their study also showed the same outcome where they supplemented their one group by fish oil (1.1g/day) and other by olive oil. In the same manner Defina et al. [34] and Tapsell et al. [35] in their studies found no significant difference in reduction of body weight among the groups. ...
Context: Current recommendations for counteracting the action of obesity advocate the consumption of a healthy diet and participation in regular physical activity. Studies have indicated towards a potential role of long-chain omega-3 polyunsaturated fatty acids (LC N-3 PUFA) in a number of effects which ameliorate the condition of obesity. Objective: To assess the effect of LC N-3 PUFA (Docosahexaenoic acid and Ecosapentaenoic acid) on obese individuals. Data sources: Using Cochrane guidelines, electronic databases-Google Scholar and PubMed-NCBI were searched for evidence from the last 10 years (March 2007-17). Study selection: Randomized Controlled Trials (RCT) based on LC N-3 PUFA supplementation involving obese adult were included. Result: The association between change in body weight/ body mass index (BMI)/ waist circumference and fish oil supplementation in 31 RCTs involving overweight or obese adults was investigated. Of the 31 studies, 9 did not provide any evidence for the biomarkers of LC N-3 PUFA intake like EPA/DHA fatty acids plasma concentration and N-3 FA percentage in serum phospholipids. The preliminary evidence suggested that LC N-3 PUFA supplementation combined with energy-restricted diets or exercises prevents weight regain. Treatment groups showed a higher drop in BMI and body fat percentage (0.24kg/m2; 0.49%) than controls. Conclusion: While there is growing evidence that LC N-3 PUFA can improve body composition, contradictory findings have also been reported. There is an urgent need for long-term studies and meta-analysis in this area of research to generate conclusive evidence on the effects of LC n-3 PUFA supplementation on obesity.
... Ancak, bu bulguların aksini gösteren çalışmalarda mevcuttur (9,10 (11). Yaşam boyu homeostaz ve normal bir gelişim için önerilen n-6/n-3 oranı 1/1-2/1'dir (12). ...
Obezite; vücutta anormal veya aşırı yağ birikimi olarak tanımlanır ve pandemik bir hastalık olarak kabul edilir. Birçok metabolik hastalığın oluşmasına neden olan obezite, aynı zamanda ülkelerin sağlık maliyetlerini de ciddi düzeylerde artırmaktadır. Bütüncül olarak yaklaşıldığında kalıcı tedavi çözümlerinin elzem olduğu görülmektedir. Tıbbi beslenme tedavisi, egzersiz ve davranış değişikliği kombinasyonunun en etkili tedavi yöntemi olduğu bilinmektedir. Bu yöntemlere ek olarak omega-3 çoklu doymamış yağ asitlerinin vücut ağırlık kaybı üzerinde etkili olabileceği düşünülmektedir. Linoleik asit ve α-linolenik asit sentezi insan vücudunda gerçekleştirilemediği için besinler ile alınması gereklidir. Özellikle eikosapentaenoik asit (EPA) ve dokosaheksaenoik asit (DHA) gibi omega-3 çoklu doymamış yağ asitlerinin, farklı metabolik değişiklikler yoluyla vücut ağırlık kaybı üzerinde etkili olabileceği belirtilmektedir. Ancak, yapılan araştırmalar incelendiğinde omega-3 çoklu doymamış yağ asitlerinin bu etkileri belirsizliğini korumaktadır. Bu derleme yazının amacı; vücut ağırlık yönetiminde omega-3 çoklu doymamış yağ asitlerinin rolü ve önerilen etki mekanizmaları hakkında literatürde yer alan güncel bilgilerin sunulmasıdır.
... Considering fat mass losses as the primary outcome, based on the results reported by previous studies on the placebo untrained group and the n-3 trained group [63,64], the estimated effect size was 1.185. Taking a bilateral alpha of 95% and a power calculation of 90%, the number of volunteers per group was 16. ...
Resistance training (RT) and n-3 polyunsaturated fatty acids (n-3 PUFA) supplementation have emerged as strategies to improve muscle function in older adults. Overweight/obese postmenopausal women (55–70 years) were randomly allocated to one of four experimental groups, receiving placebo (olive oil) or docosahexaenoic acid (DHA)-rich n-3 PUFA supplementation alone or in combination with a supervised RT-program for 16 weeks. At baseline and at end of the trial, body composition, anthropometrical measures, blood pressure and serum glucose and lipid biomarkers were analyzed. Oral glucose tolerance tests (OGTT) and strength tests were also performed. All groups exhibit a similar moderate reduction in body weight and fat mass, but the RT-groups maintained bone mineral content, increased upper limbs lean mass, decreased lower limbs fat mass, and increased muscle strength and quality compared to untrained-groups. The RT-program also improved glucose tolerance (lowering the OGTT incremental area under the curve). The DHA-rich supplementation lowered diastolic blood pressure and circulating triglycerides and increased muscle quality in lower limbs. In conclusion, 16-week RT-program improved segmented body composition, bone mineral content, and glucose tolerance, while the DHA-rich supplement had beneficial effects on cardiovascular health markers in overweight/obese postmenopausal women. No synergistic effects were observed for DHA supplementation and RT-program combination.
... Major depressive disorders (MDD) Depressive episodes in bipolar affective disorders [60][61][62][63][64][65][66][67] Depression during or post pregnancy [68][69][70] Depression in non-MDD mood disorders (e.g., premenstrual syndrome, dysthymia) [31,45,49,[71][72][73] Depression in other psychiatric conditions (e.g., borderline personality, self-harm, OCD) [74][75][76][77][78] Depression in established schizophrenia [79][80][81] Depression in Alzheimer's dementia/mild cognitive impairment [46,82,83] Depression in Parkinson's disease [84] Depression in medical conditions (cerebrovascular and metabolic diseases or cancer) [85][86][87][88][89] Depressive features in healthy individuals [90][91][92][93][94][95][96] Abbreviations: RCT: randomized controlled trial; OCD: obsessive-compulsive disorder. ...
Major depressive disorders (MDDs) are often associated with a deficiency in long-chain omega-3 polyunsaturated fatty acids (ω-3 PUFAs), as well as signs of low-grade inflammation. Epidemiological and dietary studies suggest that a high intake of fish, the major source of ω-3 PUFAs, is associated with lower rates of MDDs. Meta-analyses of randomized placebo-controlled ω-3 PUFAs intervention-trials suggest that primarily eicosapentaenoic acid (EPA), but not docosahexaenoic acid (DHA), is responsible for the proposed antidepressant effect. In this review, we dissect the current biological knowledge on EPA and DHA and their bioactive lipid metabolites to search for a pharmacological explanation of this, to date, unexplained clinical observation. Through enzymatic conversion by cyclooxygenase (COX), lipoxygenase (ALOX), and cytochrome P-450 monooxygenase (CYP), EPA and DHA are metabolized to major anti-inflammatory and pro-resolving lipid mediators. In addition, both ω-3 PUFAs are precursors for endocannabinoids, with known effects on immunomodulation, neuroinflammation, food intake and mood. Finally, both ω-3 PUFAs are crucial for the structure and organization of membranes and lipid rafts. While most biological effects are shared by these two ω-3 PUFAs, some distinct features could be identified: (1) The preferential CYP monooxygenase pathway for EPA and EPA derived eicosanoids; (2) The high CB2 receptor affinities of EPA-derived EPEA and its epoxy-metabolite 17,18-EEQ-EA, while the DHA-derived endocannabinoids lack such receptor affinities; (3) The competition of EPA but not DHA with arachidonic acid (AA) for particular glycerophospholipids. EPA and AA are preferentially incorporated into phosphatidylinositols, while DHA is mainly incorporated into phosphatidyl-ethanolamine, -serine and -choline. We propose that these distinct features may explain the superior antidepressant activity of EPA rich ω-3 PUFAs and that these are potential novel targets for future antidepressant drugs.
... This suggests changes in body fat distribution and a positive effect of these eggs on abdominal obesity. In the placebo-controlled, randomized clinical trial by Defina et al. [19] where overweight and obese individuals received n-3 PUFA supplementation (3 g/day for 6 months), no difference in weight and body composition was observed compared to the placebo group. These results were confirmed by subsequent studies in subjects with CVD and type 2 diabetes [20,21]. ...
Alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), rumenic acid (RmA), and punicic acid (PunA) are claimed to influence several physiological functions including insulin sensitivity, lipid metabolism and inflammatory processes. In this double-blind randomized controlled trial, we investigated the combined effect of ALA, DHA, RmA and PunA on subjects at risk of developing metabolic syndrome. Twenty-four women and men were randomly assigned to two groups. Each day, they consumed two eggs enriched with oleic acid (control group) or enriched with ALA, DHA, RmA, and PunA (test group) for 3 months. The waist circumference decreased significantly (-3.17 cm; p < 0.001) in the test group. There were no major changes in plasma insulin and blood glucose in the two groups. The dietary treatments had no significant effect on endothelial function as measured by peripheral arterial tonometry, although erythrocyte nitrosylated hemoglobin concentrations tended to decrease. The high consumption of eggs induced significant elevations in plasma low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol (p < 0.001), which did not result in any change in the LDL/HDL ratio in both groups. These results indicate that consumption of eggs enriched with ALA, DHA, RmA and PunA resulted in favorable changes in abdominal obesity without affecting other factors of the metabolic syndrome.
... With regard to body composition, results from a meta-analysis showed that supplementation with n3-PUFAs as monotherapy can promote moderate weight loss, including a reduction in body fat [21]. When combined with exercise some [33,34], but not all studies [35], reported an additional beneficial effect of n-3 PUFAs on body fat loss in healthy active or sedentary overweight/obese participants. However, evidence about the combined effect of n-3 PUFA supplementation and exercise on body composition in the elderly population is limited. ...
Aging is accompanied by a progressive decline in muscle mass and an increase in fat mass, which are detrimental changes associated with the development of health conditions such as type-2 diabetes mellitus or chronic low-grade inflammation. Although both exercise as well as nutritional interventions are known to be beneficial in counteracting those age-related changes, data to which extent untrained elderly people may benefit is still sparse. Therefore, a randomized, controlled, 12-week interventional trial was conducted in which 134 healthy untrained participants (96 women and 38 men, age 59.4 ± 5.6 years, body mass index (BMI) 28.4 ± 5.8 kg/m2) were allocated to one of four study groups: (1) control group with no intervention (CON); (2) 2×/week aerobic and resistance training only (EX); (3) exercise routine combined with dietary counseling in accordance with the guidelines of the German Nutrition Society (EXDC); (4) exercise routine combined with intake of 2 g/day oil from Calanus finmarchicus (EXCO). Body composition (bioelectrical impedance analysis), as well as markers of glucose metabolism and blood lipids, were analyzed at the beginning and the end of the study. The highest decreases in body fat were observed within the EXCO group (−1.70 ± 2.45 kg, p < 0.001), and the EXDC (−1.41 ± 2.13 kg, p = 0.008) group. Markers of glucose metabolism and blood lipids remained unchanged in all groups. Taken together results of this pilot study suggest that a combination of moderate exercise and intake of oil from Calanus finmarchicus or a healthy diet may promote fat loss in elderly untrained overweight participants.
... Additionally, Pedersen et al. [48] did not observe changes on metabolic rate, body composition or fat oxidation in slightly overweight adolescents who were given fish oil supplementation. Similarly, DeFina et al. [49] did not find omega-3 FAs intake to have an effect on body fat and resting metabolic rate in overweight or obese adults. However, Couet et al. [50] found reduced body fat mass and increased fat oxidation in adults with fish oil intervention. ...
Background
Childhood obesity is a major public health problem with a global prevalence greater than 23 %. Omega-3 polyunsaturated fatty acids (omega-3 FAs) supplementation may improve anthropometric indices by increased energy expenditure, attenuated appetite, elevated adiponectin levels, though current evidence is still inconclusive.
Objective
The aim of this systematic review was to conduct the first comprehensive meta-analysis of randomized controlled trials on the association between omega-3 FAs supplementation and anthropometric indices in children and adolescents.
Methods
We performed an extensive online database search of the published literature using the SCOPUS, Web of Science, PubMed, EMBASE, and Cochrane library databases from the index date through April 2019. Six studies met inclusion criteria. Changes in anthropometric indices (weight, BMI and waist circumference) were extracted from each article. Statistical heterogeneity was assessed by calculating the I² statistic. We used the standardized mean difference (SMD) with 95 % confidence interval. The meta-analysis was performed based on a random effects model.
Results
This meta-analysis demonstrated that omega-3 FAs supplementation had no effect on reducing body weight (SMD = -0.00, 95 % CI -0.26 to 0.25), BMI (SMD = -0.07, 95 % CI -0.32 to 0.17) and waist circumference (SMD = -0.16, 95 % CI -0.51 to 0.19).
Conclusions
Omega-3 FAs supplementation did not change anthropometric indices in children and adolescents. Further large-scale studies with larger sample sizes in children and adolescents are needed to clarify the effects of omega-3 FAs.
... Crochemore et al. showed that 2.5 g/d PUFA (574.5 mg EPA and 352.5 mg DHA) had no effects on BW, BMI, or glucose level on 45 post-menopausal subjects for 4 weeks [52]. In accordance with this study, no significant differences in BW were observed among 128 subjects with obesity, who were supplemented with omega-3 (3 g/day, EPA/DHA 5:1) in comparison with a placebo for 24 weeks [53]. There were no significant differences in resting metabolic rate and fatty acid oxidation in human subjects using 3 g/day fish oil (2 g/day EPA and 1 g/day DHA), for 12 weeks [54]. ...
Obesity is a widespread epidemic that increases the risk for several metabolic diseases. Despite several beneficial health effects of eicosapentaenoic acid (C20:5n-3, EPA), previous studies have used very high doses of EPA. In this study, dose-dependent effects of EPA on metabolic outcomes were determined in diet-induced obese mice. We used B6 male mice, fed high-fat diet (HF, 45% kcal fat) or HF diet supplemented with 9, 18, and 36 g/kg of EPA-enriched fish oil for 14 weeks. We conducted metabolic phenotyping during the feeding period, and harvested tissues and blood at termination. Only mice fed 36 g/kg of EPA significantly (p < 0.05) lowered body weight, fat content and epididymal fat pad weight, compared to HF. Both 18 and 36 g/kg doses of EPA significantly increased glucose clearance and insulin sensitivity, compared to HF or 9 g/kg of EPA. Locomotor activity was significantly increased with both 18 and 36 g/kg doses of EPA. Interestingly, all doses of EPA compared to HF, significantly increased energy expenditure and oxygen consumption and significantly reduced serum insulin, leptin, and triglycerides levels. These results demonstrate weight- and adiposity-independent metabolic benefits of EPA, at doses comparable to those currently used to treat hypertriglyceridemia.
... De plus, la perte de poids est également plus importante lorsque cette fois-ci, l'activité physique est associée à la prise d'AGPI-LC oméga 3 (Warner, Ullrich et al. 1989;Hill, Buckley et al. 2007). Cependant, certaines études n'obtiennent pas de perte de poids supplémentaire grâce à l'addition d'AGPI-LC oméga 3 lors d'un régime alimentaire pauvre en calories et des exercices physiques (DeFina, Marcoux et al. 2011;Munro and Garg 2012). Ainsi, les conclusions ne sont pas nettes concernant l'effet des AGPI-LC oméga 3 sur l'obésité, probablement due à la variabilité des caractéristiques phénotypiques des sujets inclus dans ces études. ...
Le Syndrome métabolique (SMet) traduit le développement de désordres glucidiques et lipidiques résultant d’une balance énergétique positive. Par ses caractéristiques, le SMet est un facteur de risque de développer un diabète de type 2 qui se caractérise dans ses formes pathologiques par des altérations vasculaires, en particulier au niveau de la rétine, créant ainsi une rétinopathie diabétique (RD). Fortement vascularisée et bien que présentant une barrière hémato-rétinienne qui limite l’entrée de composés sanguins, la rétine subit les variations métaboliques. Les conséquences du SMet dans la rétine sont peu étudiées, alors même qu’une prise en charge précoce pourrait diminuer leur importance. A cet égard, une alimentation à la fois riche en acides gras polyinsaturés (AGPI) à longue chaîne de type oméga 3, comme l’acide docosahexaénoïque (DHA) et l’acide eicosapentaénoïque (EPA) et pauvre en oméga 6 participerait à la prévention de l’insulinorésistance, une composante du SMet, et serait protectrice vis-à-vis des premiers stades de la dégénérescence maculaire liée à l’âge (DMLA) et du vieillissement de la rétine. La biodisponibilité des AGPI oméga 3 dans la rétine, est un paramètre à prendre en compte pour bénéficier de leurs effets protecteurs. Pourtant, ces données, selon la source de provenance des AGPI, sont peu accessibles et méritent d’être étudiées. Nous voulions d’abord évaluer l’effet d’un régime diabétogène sur le métabolisme glucidique et lipidique chez le rat pour, de manière concomitante, en étudier les conséquences fonctionnelles et structurales sur la rétine. Notre second objectif était de comparer l’intégration de plusieurs formulations à base de phospholipides ou triglycérides, portant EPA ou DHA, dans la rétine.Ainsi, des rats Brown Norway ont été nourris avec un régime composé de 60% de fructose et 10% de lipides saturés (HFHF). L’étude du métabolisme glucidique a révélé une hyperglycémie à jeun, une intolérance au glucose et une résistance à l’insuline dès 8 jours de régime. D’autre part, nos analyses n’ont pas révélé de dyslipidémie. Ainsi, compte tenu de la résistance de ces rats à développer de manière précoce des altérations d’un mécanisme clé du syndrome métabolique comme la dyslipidémie, nous avons réalisé une étude comparative entre rats Brown Norway (BN) et Wistar (W) soumis au régime HFHF. Cette étude a révélé que les rats W étaient plus sensibles aux dérégulations lipidiques. Toutefois, les rats W n’ont pas développé d’insulinorésistance, et présentaient une hyperglycémie à jeun plus tardive que les rats BN. En complément de ces données, les analyses fonctionnelles de la rétine des rats BN par électrorétinographie ont révélé une diminution de sensibilité des photorécepteurs de type cône, après 4 semaines de régime HFHF. De plis, nos résultats indiquent que le régime HFHF constitue un terrain favorable au développement néovasculaire dans la rétine, avec une exacerbation de l’activation des cellules de Müller.Dans l’objectif d’optimiser la forme d’apport en acides gras à effets protecteurs de la rétine, nous souhaitions comparer l’intégration du DHA dans la rétine apporté par différentes sources de lipides intégrées dans l’alimentation de rats Wistar. L’apport consistait principalement en EPA ou en DHA, soit sous forme de phospholipides, soit sous forme de triglycérides. Nos données mettent principalement en évidence un enrichissement de la couche des photorécepteurs dans une zone à proximité du nerf optique, ceci quelle que soit la formule lipidique considérée. Nos données quantitatives révèlent quant à elles une meilleure intégration du DHA, estérifié sur les phosphatidylcholines de la rétine lorsque l’EPA est apporté sous forme de phospholipides, et que le DHA est apporté par les phospholipides ou les triglycérides. L’ensemble des régimes permettent d’augmenter la teneur en AGPI à très longue chaîne dans la rétine.
... Although there is evidence showing the positive impacts of n-3 LC-PUFAs on body composition as mentioned above, some reported no significant effects of EPA+DHA supplementation on body fat and lean tissue in healthy overweight and/or obese adults (19,20). This discrepancy may be due to the variety of experimental designs, baseline characteristics of samples or participants, the high ratio of EPA to DHA, and study duration. ...
Background:
Docosahexaenoic acid (DHA; 22:6n-3) is an n-3 (ω-3) fatty acid known for beneficial effects on body composition.
Objective:
The objective of the study was to test the dose response of lean and fat mass to DHA in healthy growing female rats.
Methods:
Female Sprague-Dawley rats (7 wk at baseline; n = 12/diet) were randomly assigned to receive a control (AIN-93M; 60 g soybean oil/kg diet) or experimental diet for 10 wk. Experimental diets contained 0.1%, 0.4%, 0.8%, or 1.2% DHA (wt:wt of total diet). Imaging for whole-body and abdominal composition was conducted using dual-energy X-ray absorptiometry and microcomputed tomography, respectively, at weeks 0, 5, and 10. Fatty acid profiles of several tissues were analyzed using gas chromatography. Serum leptin, C-reactive protein, and plasma insulin-like growth factor I concentrations were measured at each time point using immunoassays. Data were tested using Pearson's correlations and mixed-model ANOVA.
Results:
No differences were observed in weight at baseline or food intake throughout the study. Overall, a 6% increase (P < 0.05) in whole-body and abdominal lean mass was observed in the 0.4%-DHA diet group compared with the control diet group. Moreover, the abdominal visceral fat mass was 31.4% lower in rats in the 0.4%-DHA than in the 1.2%-DHA diet group (P < 0.001). Rats in the 1.2%-DHA diet group showed greater percent differences in whole-body (32.5% and 40.6% higher) and in abdominal (33.9% and 49.4% higher) fat mass relative to the 0.1%- and 0.4%-DHA diet groups, respectively (P < 0.01). Accordingly, serum leptin concentration was lower in the 0.1%-DHA (38.2%) and 0.4%-DHA (43.8%) diet groups (P < 0.01) than in the 1.2%-DHA diet group and positively related to whole-body fat mass (r = 0.91, P < 0.0001).
Conclusion:
Dietary DHA at 0.4% of dietary weight effectively enhances lean mass and proportionally reduces fat mass in growing female rats.
... Some factors responsible for these inconclusive results include usage of lower doses in human studies compared to animal studies, genetic variabilities in humans compared to animal models, and different types of fatty acids and treatment durations used for clinical research. [76,77] ...
Scope
Brown adipose tissue (BAT) dissipates energy through uncoupling protein 1 (UCP1) and has been proposed as an anti‐obesity target. It was reported previously that a high‐fat (HF) diet enriched in eicosapentaenoic acid (EPA) significantly increased UCP1 and other thermogenic markers in BAT. It is hypothesized that these effects are mediated through UCP1‐dependent regulation.
Methods and results
Wild‐type (WT) and UCP1 knockout (KO) B6 male mice were housed at thermoneutrality and fed a HF diet, without or with eicosapentaenoic acid (EPA)‐enriched fish oil. HF‐fed KO mice were heavier and had higher BAT lipid content than other groups. Protective effects of EPA in WT, previously observed at 22 °C (reduced adiposity, improved glucose tolerance, and increased UCP1), disappeared at thermoneutrality. Mitochondrial proteins, cytochrome c oxidase subunit 1 (COX I), COX I, II, and IV were reduced in the KO mice compared to WT. Unexpectedly, EPA attenuated weight and fat mass gain and improved glucose tolerance in the KO mice. Finally, EPA increased BAT peroxisome proliferator‐activated receptor gamma coactivator 1 alpha (PGC1α) protein and gene expression, and whole‐body oxygen consumption in KO mice, consistent with increased mitochondria DNA (mtDNA)/nuclear DNA (nucDNA) ratio.
Conclusions
EPA rescued the weight gain and glucose intolerance in UCP1 KO mice at thermoneutrality, independent of UCP1; these effects may be mediated in part via increased oxygen consumption and BAT PGC1α.
... Although accumulating evidences regarding n-3 PUFA promotes brown/beige adipose tissue thermogenesis have been well-elucidated in mouse and in vitro cell models, the implication of this effect in human remain to be clarified. There are some studies supporting that n-3 PUFA administration in human could reduce body weight and plasma triglycerides, decrease inflammation, and increase insulin sensitivity (78,(156)(157)(158)(159)(160)(161)(162). ...
Brown adipose tissue (BAT) is a crucial regulator in energy expenditure by dissipating energy in the form of heat through mitochondrial uncoupling protein 1 (UCP1). Previously, we demonstrated that n-3 PUFA (Omega-3 Polyunsaturated Fatty Acids) increase brown adipogenesis by miRNA-mediated epigenetic mechanisms. Given that BAT is formed at the late stage of pregnancy, we hypothesized prenatal exposure of n-3 PUFA through maternal nutrition potentiates BAT development. To test this hypothesis, Female C57BL/6 mice were fed a diet containing n-3 PUFA (3%) derived from fish oil (FO), or an isocaloric diet devoid of n-3 PUFA (Cont), and same diet was maintained throughout the pregnancy and lactation. Results showed that maternal FO was effectively delivered to the offspring significantly reducing n-6/n-3 ratio, altered blood lipid profile, and upregulated brown adipose tissue specific genes and proteins. The elevated levels of brown adipose tissue signature gene profiles, i.e., Uncoupling protein 1 (UCP1), Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α), in weaned pups with maternal FO intake were correlated with higher expression of GPR120 and the functional cluster of brown-specific miRNAs including miR30b and miR193b/365. Intriguingly, augmented BAT development in offspring by maternal FO intake was also associated with 1) increased epigenetic marks at H3K27Ac and H3K9me2, and decreased histone deacetylase 1 (HDAC1), and 2) upregulation of Drosha, which is a miRNA-editing enzyme for pre-miRNA production. More importantly, benefits of maternal FO intake remained later in life showing that pups that received maternal FO presented a lower body weight at weaning, an increase in energy expenditure and higher core body temperature against acute cold exposure in later life. Taken together, our results indicated that prenatal exposure to n-3 PUFA potentiates the offspring’s BAT development, at least partly via synergistic epigenetic modifications in histone modifications and miRNA production, which may confer long-lasting metabolic benefits to offspring. Advisor: Soonkyu Chung
... On the other hand, Gammelmarka et al. [33] in their study also showed the same outcome where they supplemented their one group by fish oil (1.1g/day) and other by olive oil. In the same manner Defina et al. [34] and Tapsell et al. [35] in their studies found no significant difference in reduction of body weight among the groups. ...
Context: Current recommendations for counteracting the action of obesity advocate the consumption of a healthy diet and participation in regular physical activity. Studies have indicated towards a potential role of long-chain omega-3 polyunsaturated fatty acids (LC N-3 PUFA) in a number of effects which ameliorate the condition of obesity. Objective: To assess the effect of LC N-3 PUFA (Docosahexaenoic acid and Ecosapentaenoic acid) on obese individuals. Data sources: Using Cochrane guidelines, electronic databases-Google Scholar and PubMed-NCBI were searched for evidence from the last 10 years (March 2007-17). Study selection: Randomized Controlled Trials (RCT) based on LC N-3 PUFA supplementation involving obese adult were included. Result: The association between change in body weight/ body mass index (BMI)/ waist circumference and fish oil supplementation in 31 RCTs involving overweight or obese adults was investigated. Of the 31 studies, 9 did not provide any evidence for the biomarkers of LC N-3 PUFA intake like EPA/DHA fatty acids plasma concentration and N-3 FA percentage in serum phospholipids. The preliminary evidence suggested that LC N-3 PUFA supplementation combined with energy-restricted diets or exercises prevents weight regain. Treatment groups showed a higher drop in BMI and body fat percentage (0.24kg/m2; 0.49%) than controls. Conclusion: While there is growing evidence that LC N-3 PUFA can improve body composition, contradictory findings have also been reported. There is an urgent need for long-term studies and meta-analysis in this area of research to generate conclusive evidence on the effects of LC n-3 PUFA supplementation on obesity.
... It is of particular importance to note there are pathophysiological differences between MDD, depressive symptoms due to background (primary) disorders, and depressive patients without a diagnosis of MDD (13). It has been demonstrated for nondepressive healthy people, n-3FAs supplements have no beneficial effects regarding mood improvement (20)(21)(22)(23)(24)(25). Nearly half of T2DM patients studied in our study were not depressed at baseline (based on the cut-off of 16 of BDI-II-PERSIAN scores (16) for Iranian population). ...
Background
Type 2 diabetes mellitus (T2DM) is commonly associated with depressive symptoms, which affect prognosis and quality of life. We investigated the antidepressant effects of n-3 fatty acids (n-3FAs) monotherapy (without conventional antidepressants) for T2DM patients with mild to moderate depressive symptoms.
Methods
A 10-wk, placebo-controlled, double-blind, parallel-group (1:1 ratio) randomized trial of n-3FAs (2700 mg/day EPA: DHA ratio=2) versus placebo in 88 Iranian diabetic patients with mild to moderate depression based on Beck Depression Inventory II (BDI-II-PERSIAN) was conducted. This study started from July 2014 to January 2015 in Tehran University of Medical Sciences, Tehran, Iran. The primary event was defined as worsened, non-changed, or inconsiderably improved depression (<5 unit decrease in BDI-II-PERSIAN depression scores after treatment) (ClinicalTrials.gov Identifier: NCT02261545).
Results
Randomly, 44 T2DM patients were treated with n-3FAs supplements and 44 cases received placebo (three patients discontinued). n-3FAs could significantly protect patients against the aforesaid event and exhibit satisfactory prevention (number needed to treat with 95% confidence interval: 2.52, 1.71–4.74). No serious adverse reactions were reported.
Conclusion
n-3FAs supplementation had significant antidepressant effects in T2DM patients with mild to moderate depressive symptoms, not confounded by metabolic factors and disease duration.
... In these studies, the average weight loss was 6.5 kg for males and 4.2 kg for females. Interestingly, no significant differences were observed when overweight insulin-resistant females were given omega-3 supplements (4.2 g/d EPA C DHA, DHA: EPA D 2.2: 1) in combination with a very low energy diet (Krebs et al. 2006), or when 138 overweight to obese male and female participants were given omega-3 supplements (3 g/day EPA C DHA, DHA: EPA D 0.2: 1) coupled with an energy-controlled diet and exercise (DeFina et al. 2010). The conflicting results reported above could be due to differences in the amount of omega-3 consumed and the different DHA: EPA ratios used in the studies, as previously described for several studies focusing on omega-3 metabolism (Ghasemifard et al. 2014). ...
The health benefits of fish oil, and its omega-3 long chain polyunsaturated fatty acid content, have attracted much scientific attention in the last four decades. Fish oils that contain higher amounts of eicosapentaenoic acid (EPA; 20:5n-3) than docosahexaenoic acid (DHA; 22:6n-3), in a distinctive ratio of 18/12, are typically the most abundantly available and are commonly studied. Although the two fatty acids have traditionally been considered together, as though they were one entity, different physiological effects of EPA and DHA have recently been reported. New oils containing a higher quantity of DHA compared with EPA, such as fractionated and concentrated fish oil, tuna oil, calamari oil and microalgae oil, are increasingly becoming available on the market, and other oils, including those extracted from genetically modified oilseed crops, soon to come. This systematic review focuses on the effects of high DHA fish oils on various human health conditions, such as the heart and cardiovascular system, the brain and visual function, inflammation and immune function and growth/Body Mass Index. Although inconclusive results were reported in several instances, and inconsistent outcomes observed in others, current data provides substantiated evidence in support of DHA being a beneficial bioactive compound for heart, cardiovascular and brain function, with different, and at times complementary, effects compared with EPA. DHA has also been reported to be effective in slowing the rate of cognitive decline, while its possible effects on depression disorders are still unclear. Interestingly, gender- and age- specific divergent roles for DHA have also been reported. This review provides a comprehensive collection of evidence and a critical summary of the documented physiological effects of high DHA fish oils for human health.
... With the addition of n-3 PUFA to an exercise regimen and dietary intervention, only one study has shown a decrease in body weight [82]. However, only a few such studies have been conducted, and the dietary intervention consisted of nutritional counseling rather than a prescribed diet [83,84]. ...
Strategies to reduce obesity have become public health priorities as the prevalence of obesity has risen in the United States and around the world. While the anti-inflammatory and hypotriglyceridemic properties of long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) are well known, their antiobesity effects and efficacy against metabolic syndrome, especially in humans, are still under debate. In animal models, evidence consistently suggests a role for n-3 PUFAs in reducing fat mass, particularly in the retroperitoneal and epididymal regions. In humans, however, published research suggests that though n-3 PUFAs may not aid weight loss, they may attenuate further weight gain and could be useful in the diet or as a supplement to help maintain weight loss. Proposed mechanisms by which n-3 PUFAs may work to improve body composition and counteract obesity-related metabolic changes include modulating lipid metabolism; regulating adipokines, such as adiponectin and leptin; alleviating adipose tissue inflammation; promoting adipogenesis and altering epigenetic mechanisms.
... The first prescription given by physicians to fight against obesity consists in reducing the calorie intake and increasing the physical activity. Although the ingestion of some specific nutrients have been considered in facilitating the fat loss effort: for example, green tea extract (6-8) and n-3 polyunsaturated fatty acid (PUFA) eicosapentaenoic acid (EPA) (9)(10)(11)(12)(13)(14)(15). However, the effects of these nutrients are controversial, at best limited, and cannot totally replace the required effort to limit food intake and increase regular exercise. ...
Part of this work was performed in the Laboratory of Fundamental and AppliedBioenergetic, INSERM U1055, Université Grenoble Alpes, France.
... In rats, 7 weeks of a diet with 17.4% EPA and 10.1% DHA (% of total FA) reduced VAT accumulation with no difference in body weight compared to lard-fed rats (high-fat regimen used as control) (Rokling-Andersen et al. 2009). In human studies, some authors found that supplements of EPA/DHA reduce WC ( Kunesova et al. 2006, Thorsdottir et al. 2007, Bays et al. 2009, DeFina et al. 2011, Crochemore et al. 2012, Munro and Garg 2012, Bender et al. 2014). In a group of 30 Japanese men and women with coro- nary heart disease, a supplement of 1800 mg administered over 6 months decreased SAT and VAT assessed by CT, but only the latter was also associated with the expected increase of plasma EPA level ( Sato et al. 2014). ...
... Some studies show that fish oil can reduce waist-hip ratio (WHR) in humans (DeFina et al. 2010;Munro and Garg, 2013;Du et al. 2015). Nevertheless, in our study, no significant differences were observed in WHR in both girls and boys supplemented with any of the four different doses used (Table V). ...
Overweight and obesity are considered global health problems. In Mexico, the prevalence of overweight and obesity among children is growing. Specifically, Veracruz is the Mexican state with the highest rates of childhood overweight and obesity. The present study focuses on evaluating the effect of omega-3 fatty acids (ω-3) supplements in overweight and obese schoolchildren living in Xalapa, Veracruz, Mexico. A total of 121 children, aged 10-12 years, were recruited from five public elementary schools from Xalapa city. The schoolchildren were diagnosed as being overweight or obese and divided into four groups in order to be daily supplemented with 2 or 3 gummies (70 or 105mg of DHA) and 10 or 15g of salmon per day. Supplementation was carried out for three months. Anthropometric measurements (weight, height, BMI, waist-hip ratio) were taken, and serum parameters such as glucose, triglycerides, cholesterol, HDL, VLDL and LDL were determined. The results showed no significant differences in body weight, height, BMI, waist-hip ratio and fat percentage after supplementation. In glucose, percentage change in all supplementations demonstrated no statistical difference. Cardiovascular risk biomarkers decreased: serum CHO, LDL, VLDL, TG and AI, while serum HDL increased. Supplementation of ω-3 fatty acids in children had a beneficial effect on dyslipidemia and, thus, would reduce the expectation of developing cardiovascular diseases.
... The beneficial effects of VLCD in achieving short term weight reduction has been linked to reduction in caloric intake and resting energy expenditure (28). Omega-3 PUFA supplementation on the other hand has not been largely associated with weight loss, even when used as an adjunct to lifestyle modification (29). Thus, the weight loss seen in our omega-3-PUFA group may highlight a new advantage of this dietary supplement. ...
Background: A large liver can be a bariatric surgeon’s nightmare as it interferes with the operative field particularly during posterior fundal and hiatal dissection. Various methods have been employed to achieve hepatic volume reduction (HVR) prior to surgery. This study aims to compare the effect of ome-ga-3-polyunsaturated fatty acid (PUFA) supplements and very low calorie diet (VLCD) restriction on hepatic volume.
Methods: A total of 52 obese patients were randomized into two groups. For various reasons only 41 patients were included for final analysis; VLCD group (n=20) and omega-3-PUFA group (n=21). MRI vo-lumetry of liver, weight, and serum alanine transaminase (ALT) levels were measured at enrollment and again at 4 weeks.
Results: Mean HVR of VLCD group and omega-3-PUFA group at day-30 was 37.10±15.76 and 34.88±9.99 cm3. Comparative analysis of HVR between the two groups showed no statistical dif-ference (P=0.29). Similarly there was no statistical difference in ALT levels of both groups. Significant weight loss (kg) was noted in both VLCD and omega-3-PUFA group, measuring up to 2.21±2.29 and 2.85±4.62, although no sta-tistical difference was noted when compared between the two (P=0.58).
Conclusions: Pre-operative hepatic volume and weight reduction were noted in both groups with no superiority of one modality over the other. As dietary restriction is often confronted with non-compliance, omega-3-PUFA does appear to be a more attractive alternative. A larger study including cost effec-tiveness analysis may be able to further ascertain the economic impact and feasibility of pre-bariatric surgery ome-ga-3-PUFA supplementation in a developing economy such as Malaysia.
... This study identified no effect of administration of ω-3 PUFA on FFM, FM, trunk fat mass, and anthropometric parameters in patients with CAD. These findings are in agreement with previously conducted studies that have examined the effect of supplementation with longchain PUFA on body composition indices in overweight and obese subjects (Crochemore, Souza, de Souza, & Rosado, 2012;DeFina, Marcoux, Devers, Cleaver, & Willis, 2010;Harden et al., 2014;Hill, Buckley, Murphy, & Howe, 2007;Krzymińska-Siemaszko et al., 2015;). The current study also examined the effects of ω-3 PUFA supplementation on lipid profile. ...
Adipokines are mediators of body composition and are involved in obesity-related complications
such as cardiovascular disease. Omega-3 supplementation has not been studied in the settings of
body composition and follistatin-like 1 (FSTL1) levels in patients with coronary artery disease
(CAD). This study aimed to investigate the effect of omega-3 polyunsaturated fatty acid (w-3
PUFA) supplementation on body composition indices and serum levels of FSTL1 in CAD
patients. A total of 42 male (aged 45-65 years) subjects with angiographically confirmed CAD
were included in this randomized, double-blind, placebo-controlled trial study. The subjects were
randomly divided into omega-3 and placebo groups. During the 8-week intervention, the omega-
3 group received 1200 mg of omega-3 daily, while the placebo group received paraffin. Before
and after the study, anthropometric measurements and body composition components were taken; serum FSTL1 levels were assessed by ELISA kit. In the omega-3 group, a significant
27.6% increase in serum FSTL1 was seen after 8 weeks of intervention (P=0.001), but no
significant difference in post-treatment levels of FSTL1 was observed between the two groups
(P>0.05). At the end of the study, a significant decrease in LDL-cholesterol (94.29±22.04 vs
112.24±24.5; P=0.01) and hs-CRP (1.92±0.79 vs 3.19±2.51; P=0.03) concentration was detected
between the two groups. Changes in fasting blood sugar, fasting insulin, body composition, and
anthropometric parameters were not significant within and between the groups. Oral omega-3
might increase FSTL1 and decrease LDL-cholesterol and hs-CRP concentrations in CAD
patients. However, omega-3 supplementation did not have any effect on FSTL1 levels between
the groups.
... An example of unsuspected interactions were evidenced after treatments combining exercise, essential ω-3 and ω-6 fatty acids in realistic animal models [40]. In man the combination with exercise also reveals unsuspected and occasionally disappointing results on the basis of gene studies [41] indicating that despite their effects on transcription ω-3 fatty acids were not effective as an adjunct for weight loss by modification of lifestyle and exercise in an overweight population. For all these reasons and before a few biomarkers consistent with particular lipid metabolism indicators are firmly established, the methods developed for multivariate analysis are expected to play a prominent role in human lipidomics. ...
The lipidome of the liver and the secreted circulating lipoproteins can now be interrogated conveniently by automated mass spectrometric methods. Multivariate analysis of the liver and serum lipid composition in various animal modes or in human patients has pointed to specific molecular species markers. The perturbations of lipid metabolism can be categorized on the basis of three basic pathological mechanisms: (1) an accelerated rate of de novo lipogenesis; (2) perturbation of the peroxisome pathway of ether-lipid and very-long-chain fatty acid biosynthesis; (3) a change in the rate of interconversion of essential omega-3 and-6 polyunsaturated fatty acids. This review provides examples to illustrate the practicalities of lipidomic studies in biomedicine.
... There is no consensus in the literature regarding N-3 supplementation and positive changes in body composition. DeFina et al. [19] found no effects of N-3 supplementation combined with aerobic exercise to improve body composition in sedentary individuals, however Hill et al. [1] conducted a study with similar interventions and observed significant decreases in body fat mass. Furthermore, Smith et al. [20] did not verify significant improvements in body weight, total body fat mass or intermuscular fat content in elderly people after 6-months of supplementation, however there were significant increases in thigh muscle volume, handgrip strength, and 1RM strength of leg press, chest press, knee extension, and knee flexion. ...
PurposeThe present study aimed to determine whether supplementation with omega-3 fatty acid (N-3) contributes to improving body composition, strength performance, and neuromuscular fatigue resistance in physically active men. Methods
The study was randomized, double–blind, and placebo controlled. 15 males were recruited and randomly assigned into two groups, N-3 supplementation (GN-3; N = 7) and placebo supplementation (GP; N = 8). Supplementation with N-3 or a placebo (safflower oil) was administered for 28-days at 1.4 g·day−1. During this period, physical activity was monitored (internal load = volume × perceived exertion scale). Before and after the supplementation period, body composition, one maximum repetition of knee extension (1RM), and maximum repetitions of knee extension with 70 % of 1RM load (RMs) pre and post an incremental running protocol until exhaustion were measured. ResultsANOVA two way (p < 0.05) revealed a decrease in body fat mass (GP before: 8.3 ± 2.1 kg × after: 7.7 ± 2.4 kg; GN-3 before: 12.8 ± 9.4 kg × after: 11.8 ± 9.3 kg), increase in lean mass (GP before: 61.8 ± 4.1 kg × after: 62.7 ± 3.9 kg; GN-3 before: 64.2 ± 5.8 kg × after: 66.2 ± 6.0 kg), and 1RM (GP before: 111.3 ± 29.1 kg × after: 111.3 ± 25.9 kg; GN-3 before: 115.0 ± 36.2 kg × after: 129.1 ± 39.9 kg) in the GN-3, without significant alterations in the GP and no interactions between-groups. Moreover, the absolute variation of the RMs pre and post the incremental running protocol were not significantly altered for both group (GP before: −1.1 ± 2.9 repetitions × after: −1.1 ± 2.6 repetitions; GN-3 before: −3.9 ± 2.9 repetitions × after: −5.0 ± 4.6 repetitions), with no interactions between-groups. Conclusion
Four weeks of N-3 supplementation seems to improved body composition and maximal strength of knee extension, without influencing neuromuscular fatigue resistance.
... Therefore, even in conditions like schizophrenia, depression or attention deficit and hyperactivity disorders (ADHD) where most omega-3 fatty acid RCTs have been performed, no final conclusions regarding the use of omega-3 fatty acids can be drawn yet. One of the key problems of systematic reviews investigating the use of omega-3 fatty acids in mental disorders is that they have integrated quite diverse phenotypic groups, e.g., the use of omega-3 fatty acids in controlled treatment trials that also assessed depressive symptoms included the following different conditions: Primary diagnosis of adult major depressive disorders (MDD) [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Depressive episodes in bipolar affective disorders [17][18][19][20][21][22][23] Depression during or post pregnancy (postpartum depression) [24][25][26] Depression in non-MDD mood disorders (e.g., premenstrual syndrome, dysthymia) [27][28][29][30][31][32] Depression in other psychiatric conditions (e.g., borderline PD, self-harm, OCD) [33][34][35][36][37] Depression in established schizophrenia [2,38] Depression in Alzheimer's dementia/mild cognitive impairment [13,39,40] Depression in Parkinson disease [41] Depression in medical conditions (cerebro-vascular and metabolic diseases or cancer) [42][43][44][45][46] Depressive symptoms in healthy individuals [47][48][49][50][51][52] ...
Paola Bozzatello et al. [1] have done a comprehensive qualitative review of the potential use of long-chain polyunsaturated fatty acids in the prevention and treatment of mental disorders.[...].
The aim of this study was to investigate the effect of 8 weeks resistance training accompany with Omega_3 fatty acid supplement on muscle strength, aerobic endurance and body composition of healthy elderly women. Twenty-four elderly women (mean±SD; age: 79.6 ± 4.2 y, height 151.7± 4.2cm, weight 60.8±7.8kg) were selected and randomly divided into 3 groups, resistance training, resistance training accompany with Omega_3 fatty acid supplement and control groups. The subjects in resistance training group performed resistance training for duration of 8 weeks by 60 to 80 percent 1 RM. The subjects of resistance training accompany with Omega_3 fatty acid group in addition to resistance training consumed Omega_3 fatty acid supplement 3 gram daily, but the subjects in the control group didn't receive any treatment. Strength of upper extremities (left and right hand), lower extremities strength, aerobic endurance and body composition were evaluated before and after 8 weeks training program. Data were analyzed using dependent t- test, variance analysis and Tukey's test (P ≤ 0.05). After 8 weeks, a significant difference (P<0.05) was observed in upper extremities strength, lower extremities strength among 3 groups, as resistance training group and resistance training accompany with Omega_3 fatty acid supplement group had more strength than control group. In addition to this, the resistance training accompany with Omega_3 fatty acid group were stronger than resistance training. Regarding aerobic endurance similar results were observed. In relation to body compositions, a significant decrease of waist hip ratio in resistance training accompany with Omega_3 fatty acid supplement group was found. Same results were observed for BMI. It can be concluded that the resistance training along with Omega_3 fatty acid supplement have more effect on muscle strength, aerobic endurance and body compositions of healthy elderly women, therefore, to improve performance of healthy elderly women, resistance training accompany with consuming Omega_3 fatty supplement are recommended.
234 ت اثیر 12 یاری مکمل همراه به هوازی تمرینات هفته OMG3 های فاکتور بر التهابی پیش در چاق زنان فعال غیر بابایی سولماز انسانی، علوم دانشکده ورزشی، علوم گروه ورزشی، فیزیولوژی دانشیار دانشگاه مراغه، مراغه، ایران s.babaei@maragheh.ac.ir دانشگا مراغه، شرقی، آذربایان مراغه. ه 09143215066 چکیده ت بررسی حاضر تحقیق انجام از هدف مدت طوالنی تمرین دوره یک اثیر ایروبیک امگا یاری مکمل و 3 های فاکتور بر التهابی خطرزای و عروقی قلبی های بیماری سرم لیپوپروتئین سطوح چاق زنان در کور، سویه دو مطالعه یک در بود. 40 (چاق زن 30 BMI≥) 30 تا 35 در تصادفی طور به و انتخاب دسترس در نمونه صورت به ساله 4 گروه 15 ورزش نفری-ورزش مکمل،-قرار دارونما و مکمل دارونما، شدت با ایروبیک تمرینات شامل تمرینی پروتکل گرفتند. 60 تا 75 مدت به بیشینه قلب ضربان درصد ۸ ، هفته 60 و دقیقه 3 جلسه آزمود بود. هفته در روزانه مکمل مصرف گروه های نی 20۸0 امگا گرم میلی-3 دکستروز محلول داروی شبه از نیز دارونما و 2 % استفاده خونی های نمونه شد. 24 و تمرینی برنامه شروع از قبل ساعت 4۸ برای همچنین شدو آوری جمع تمرینی جلسه آخرین از بعد ساعت افزار نرم از ها داده آنالیز spss استفاده که داد نشان حاضر تحقیق نتایج شد. HDL-C ورزش های گروه در-ورزش مکمل،-و دارونما همچنین نبود. دار معنی افزایش این دارونما گروه در اما داشت داری معنی افزایش مکمل SICAM-1 و sVCAM-1 و سرم TG در ورزش های گروه-ورزش ترکیب و مکمل و دارونما-داشت. داری معنی کاهش مکمل میزان همچنین LDL-C کاهش ها گروه تمامی در ورزش و مکمل گروه در کلسترول میزان آن بر عالوه و دارونما و مکمل گروه در جز به داد نشان-داشت( را داری معنی تاثیر مکمل 5 % p< می کلی طور به .) امگا مکمل مصرف همراه به هوازی ورزش های فعالیت انجام که گرفت نتیجه توان 3 تاث فاکتور کاهش در بسزایی یر باشد. داشته چاق زنان در عروقی و قلبی زای بیماری های واژه کلیدی: های sVCAM-1, sICAM1 ، امگا-3 ، تمرینات هوازی
Background
Overweight and obesity are considered as one of the major risk factors for cardiovascular diseases (CVD). At present, many studies have proved that multiple nutritional supplements play an active role in metabolic diseases. However, the comparative efficacy of different nutritional supplements in improving indicators of cardiometabolic risk in obese and overweight patients is uncertain.
Methods
Cochrane Library, PubMed, Embase, and Web of Science were searched for the period from January 1990 to March 2022. A random-effect model was built in the Bayesian network meta-analysis. The surface under the cumulative ranking analysis (SUCRA) and clustering rank analysis was performed for ranking the effects.
Results
The study included 65 RCTs with 4,241 patients. In terms of glucose control, probiotic was more conductive to improve FBG (MD: −0.90; 95%CrI: −1.41 to −0.38), FINS (MD: −2.05; 95%CrI: −4.27 to −0.02), HOMA-IR (MD: −2.59; 95%CI −3.42 to −1.76). Probiotic (MD: −11.15, 95%CrI −22.16 to −1.26), omega-3 (MD: −9.45; 95%CrI: −20.69 to −0.93), VD (MD: −17.86; 95%CrI: −35.53 to −0.27), and probiotic +omega-3 (MD: 5.24; 95%CrI: 0.78 to 9.63) were beneficial to the improvement of TGs, TC and HDL-C, respectively. The SUCRA revealed that probiotic might be the best intervention to reduce FBG, FINS, HOMA-IR; Simultaneously, α-lipoic acid, VD, and probiotic + omega-3 might be the best intervention to improve TGs, TC, and HDL-C, respectively. Cluster-rank results revealed probiotic had the best comprehensive improvement effect on glucose metabolism, and probiotic + omega-3 may have a better comprehensive improvement effect on lipid metabolism (cluster-rank value for FBG and FINS: 3290.50 and for TGs and HDL-C: 2117.61).
Conclusion
Nutritional supplementation is effective on CVD risk factors in overweight and obese patients. Probiotic supplementation might be the best intervention for blood glucose control; VD, probiotic + omega-3 have a better impact on improving lipid metabolism. Further studies are required to verify the current findings.
RESUMEN Introducción: La obesidad hoy en día es un grave problema de salud pública a nivel mundial, nacional y local, por lo que se ha estudiado el papel de los ácidos grasos omega-3 en la regulación del peso corporal. Objetivo: Conocer el efecto benéfico de la suplementación con omega-3 en seres humanos con obesidad. Material y Método: Se realizó una búsqueda en cuatro bases de datos en línea donde el tamaño de muestra fue de 34 a 154 participantes, todos los participantes comprendían con un IMC >30y <40 kg/m2 y una edad adulta promedio de 18 a 70 años. La duración de la intervención con suplementación de omega-3 fue de 10 a 30 semanas, utilizando una dosis de 300 mg a 4 gramos. Resultados: La suplementación con los ácidos grasos omega-3, durante 10 a 30 semanas con una dosis de 1 a 3 gramos, podrían ayudar a mejorar el índice de masa corporal (IMC) y el índice cintura-cadera (ICC), al igual que la modulación inflamatoria en las adipocinas IL8 y la proteína C reactiva. Conclusiones: La evidencia de la eficacia de la suplementación con los ácidos grasos omega-3 para la pérdida de peso no es sólida, por lo que es importante continuar investigando y revisando sus efectos. Las limitaciones del estudio: número limitado de estudios, además las investigaciones se realizaron en modelos animales.
Palabras Clave: obesidad, ácidos grasos omega 3, suplementos dietéticos.
Fish oil has been widely applied in fortified food products because of its special health benefits especially containing high unsaturated fatty acids mainly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Nowadays, there are various foods fortify with fish oil available in the market. The main challenge of fortification of food products with fish oil is its highly susceptible to oxidation and its influence on sensory attributes during
storage. The fortification methods such as direct addition through bulk fish oil, emulsion or microencapsulation could effectively improve the oxidative stability of fish oil and mask unpleasant fishy flavour in fortified products. Therefore, this article provides a review of techniques, their advantages and limitations, together with the effects of incorporating fish oil in foods products.
Objectives
There is evidence to suggest that omega-3 fatty acids (ω-3FA) may have an anabolic effect on the skeletal muscle. However, questions about dosage, frequency, combined protein supplementation or different physical exercises remain unanswered. Our objective is to quantify by stereology whether supplementation with high dosages of ω-3FA combined to swimming has an anabolic effect on the skeletal musculature and on the lipid profile of rats.
Methods
Sixty male Wistar rats were divided into four groups: placebo sedentary (PS), ω-3FA sedentary (ω-3S), placebo exercise (PE) and ω-3FA exercise (ω-3E). The animals in the PE and ω-3E groups were submitted to swimming five days a week, with an overload of 15% of body weight. The animals received ω-3FA or olive oil (placebo) by gavage. After euthanasia, blood samples and the gastrocnemius muscle were collected for analysis.
Results
Our results demonstrated no difference in the cross-sectional areas of the gastrocnemius muscle between groups. The administration of high doses of ω-3FA reduce plasmatic concentrations of LDL. In addition, there is an interaction effect between physical exercise and supplementation with omega 3 on the levels of HDL. Therefore, the association between these two treatments increased the levels of HDL.
Conclusions
We concluded that the administration of high doses of omega-3 associated with physical activity may be beneficial in the treatment of dyslipidemia. High doses of ω-3FA does not cause muscle mass alteration.
Omega-3 fatty acids and vitamin D3 have beneficial effects on different blood, cardiovascular parameters and physical performance. However, the effect of low-dose omega-3 fatty acid supplementation remains unclear. 84 office workers aged 40-60 years, participated in a 16-week open, randomized, placebo-controlled, parallel-group study. The experimental group received 330 mg of omega-3 fatty acid and 0.005 mg (200 IU) of vitamin D3 per day and the control group received placebo. Anthropometric, biochemical blood and respiratory indices were measured at 12 and 16 weeks. Body mass (BM) and body mass index (BMI) significantly reduced in both the experimental (BM from 74.4 ± 13.04 to 73.2 ± 13.02 kg, p < 0.001; BMI from 25.8 ± 4.1 to 25.4 ± 4.3 kg/m2, p < 0.001) and the placebo groups (BM from 69.5 ± 11. to 68.7 ± 11.4 kg, p < 0.05; BMI from 24.1 ± 4.0 to 23.8 ± 4.2 kg/m2, p < 0.05). Omega-3 fatty acid supplementation significantly improved glucose (from 5.12 ± 0.55 to 4.97 ± 0.62 mmol/l; p = 0.05), total cholesterol (from 5.86 ± 1.0 to 5.32 ± 1.55 mmol/l; p = 0.003), and vitamin D levels (from 35.07 ± 21.65 to 68.63 ± 25.94 nmol/l; p = 0.000). Maximal oxygen consumption (from 33.7 ± 2.4 to 36.6 ± 3.2 ml/kg/min, p = 0.035), forced vital capacity (from 3.5 ± 0.6 to 3.9 ± 0.9 l, p = 0.044), forced expiratory volume (from 3.2 ± 0.6 to 3.5 ± 0.7 l, p = 0.014), and peak expiratory flow (from 6.7 ± 1.4 to 7.5 ± 1.6 l/s, p = 0.019) also slightly improved in the omega-3 fatty acid group. Daily supplementation of 330 mg of omega-3 fatty acids had a slight positive impact on total cholesterol and glucose level, while there was no effect on low and high density lipoproteins, and triglycerides levels. Therefore, dose of 330 mg per day seems as insufficient.
Background & Aims
This study explored whether moderate weight loss or a reduction in interleukin (IL)‐6 improve the serum iron status in overweight (OW) and obese adults supplemented with or without fish oil.
Methods and Results
In total, 93 OW /obese Taiwanese adults with ≥2 metabolic components were randomized to a 12‐week calorie‐restricted diet with meal replacement alone (CRMR, n = 45) or supplemented with fish oil (CRMRF, n = 48). Mean reductions in the % body weight and serum IL‐6 were 7.5% vs. 5.9% and 21% vs. 35% for the CRMR and CRMRF groups, respectively. In the CRMRF group, a moderate loss of IL‐6 (reduced ≥35%) also significantly improved the serum iron and transferrin saturation compared to those with loss of <35% in the mean serum IL‐6 or those of the CRMR group who had a moderate loss of IL‐6 (reduced ≥21%) (all p<0.05). In contrasting, modest weight loss did not improve the serum iron status.
Conclusions
Fish oil was ineffective as an adjunct for weight or fat loss but had beneficial effects on preserving the lean body mass. A significant improvement in the iron status was only observed in those with moderate loss of serum IL‐6 supplemented with fish oil.
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The efficacy of omega-3 fatty acids for maintaining a better mental state has not been examined among working populations. We aimed to explore the effectiveness of omega-3 fatty acids for hospital nurses. In a multi-center randomized trial, 80 junior nurses were randomly allocated to either omega-3 fatty acids (1200 mg/day of eicosapentaenoic acid and 600 mg/day of docosahexaenoic acid) or identical placebo pills for 13 weeks. The primary outcome was the total score of the Hospital Anxiety and Depression Scale (HADS), determined by a blinded rater at week 26 from the study enrolment. Secondary outcomes included the total score of the HADS at 13 and 52 weeks; incidence of a major depressive episode; severity of depression, anxiety, insomnia, burnout, and presenteeism; utility scores; and adverse events at 13, 26 and 52 weeks. The mean HADS score at baseline was 7.2. At 26 weeks, adjusted mean scores on the HADS were 6.32 (95% CIs of standard errors: 5.13, 7.52) in the intervention and 6.81 (5.57, 8.05) in the placebo groups, respectively. The coefficient of the group by time interaction was not statistically significant at 0.58 (-1.35, 2.50; P = 0.557). Although the intervention group showed significant superiority on the HADS score at 52 weeks, depression severity at 52 weeks, insomnia severity at 13 weeks, and absolute presenteeism at 26 weeks, no significant superiority or inferiority was observed on the other outcomes. The additive value of omega-3 fatty acids was not confirmed regarding mental state and self-evaluated work efficiency.
The current paradigms of prevention and treatment are unable to curb obesity rates, which indicates the need to explore alternative therapeutic approaches. Obesity leads to several damages to the body and is an important risk factor for a number of other chronic diseases. Furthermore, despite the first alterations in obesity being observed and reported in peripheral tissues, studies indicate that obesity can also cause brain damage. Obesity leads to a chronic low-grade inflammatory state, and the therapeutic manipulation of inflammation can be explored. In this context, the use of n -3 PUFA (especially in the form of fish oil, rich in EPA and DHA) may be an interesting strategy, as this substance is known by its anti-inflammatory effect and numerous benefits to the body, such as reduction of TAG, cardiac arrhythmias, blood pressure and platelet aggregation, and has shown potential to help treat obesity. Thereby, the aim of this narrative review was to summarise the literature related to n -3 PUFA use in obesity treatment. First, the review provides a brief description of the obesity pathophysiology, including alterations that occur in peripheral tissues and at the central nervous system. In the sequence, we describe what are n -3 PUFA, their sources and their general effects. Finally, we explore the main topic linking obesity and n -3 PUFA. Animal and human studies were included and alterations on the whole organism were described (peripheral tissues and brain).
Purpose
We aimed to evaluate the effects of the omega-3 supplementation on body weight and depression among women with co-morbidity of depression and obesity seeking weight reduction compared with the placebo.
Methods
Sixty five patients with co-morbidity of depression and overweight/obesity (BMI ≥ 25) signed the informed consent form and enrolled into this 12-week double-blind, placebo-controlled randomized clinical Trial. Subsequently, participants randomly assigned into one of the two groups receiving daily 6 capsules of omega-3 (each capsule containing 180 mg EPA, and 120 mg DHA) or 6 capsules of placebo (two with each meal). We performed body composition assessments and Beck depression inventory at the baseline, and weeks 2, 4, 8, and 12 after the start of the study. One month after stopping the capsules at the follow-up visit, weight was measured to compare weight relapse between the two groups.
Results
Forty five patients finished the study. No significant differences were seen between groups regarding demographic and clinical variables at baseline. Using repeated measures ANOVA, omega-3 significantly reduced depression compared with the placebo (P = 0.05). Mean ± SD weight reduction in omega-3 group 3.07 ± 3.4 kg and in the placebo group was 1.16 ± 2.7 kg and the difference between groups was significant using independent sample t-test (p = 0.049). Patients in the omega-3 group did not show significantly more side effects compared to the placebo but they were not successful in preventing weight regain one month after the end of the study.
Conclusion
Based on our findings omega-3 capsule as a safe over-the-counter supplement might be helpful in reducing the signs of depression and also body weight in patients with co-morbidity of depression and obesity.
Objective
Most weight loss research focuses on weight as the primary outcome, often to the exclusion of other physiological or psychological measures. This study aims to provide a holistic evaluation of the effects from weight loss interventions for individuals with obesity by examining the physiological, psychological and eating disorders outcomes from these interventions. Methods
Databases Medline, PsycInfo and Cochrane Library (2011–2016) were searched for randomised controlled trials and systematic reviews of obesity treatments (dietary, exercise, behavioural, psychological, pharmacological or surgical). Data extracted included study features, risk of bias, study outcomes, and an assessment of treatment impacts on physical, psychological or eating disorder outcomes. ResultsFrom 3628 novel records, 134 studies met all inclusion criteria and were evaluated in this review. Lifestyle interventions had the strongest evidence base as a first-line approach, with escalation to pharmacotherapy and bariatric surgery in more severe or complicated cases. Quality of life was the most common psychological outcome measure, and improved in all cases where it was assessed, across all intervention types. Behavioural, psychological and lifestyle interventions for weight loss led to improvements in cognitive restraint, control over eating and binge eating, while bariatric surgery led to improvements in eating behaviour and body image that were not sustained over the long-term. DiscussionNumerous treatment strategies have been trialled to assist people to lose weight and many of these are effective over the short-term. Quality of life, and to a lesser degree depression, anxiety and psychosocial function, often improve alongside weight loss. Weight loss is also associated with improvements in eating disorder psychopathology and related measures, although overall, eating disorder outcomes are rarely assessed. Further research and between-sector collaboration is required to address the significant overlap in risk factors, diagnoses and treatment outcomes between obesity and eating disorders.
In this study, we evaluated the onset and resolution of inflammation in control and macadamia oil‐supplemented rats after a single session of exhaustive exercise. We also analysed the antioxidant enzymes catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), and thiobarbituric acid reactive substances (TBARS). Rats were supplemented for ten days with macadamia oil (25 mg/kg), which is rich in oleic and palmitoleic acids. On the 10th day, control and macadamia oil‐treated rats exercised to physical exhaustion. Plasma and muscular levels of pro‐inflammatory cytokines (tumour necrosis factor alpha [TNF‐α], interleukin‐1 beta [IL‐1β], IL‐6, cytokine‐induced neutrophil chemoattractant‐3 [CINC‐3], macrophage inflammatory protein‐3‐alpha [MIP‐3α]) and soluble L‐selectin were measured prior to, immediately after, and 2, 24, and 48 h after exercise. Our data revealed increases in the muscle concentrations of IL‐1β, L‐selectin, CINC‐3, and MIP‐3α in the group supplemented with macadamia oil compared with the concentrations in the control group. CAT also increased in the treated group, which is important because pro‐inflammatory cytokines precede growth factor production and might alter the muscle repair process. We concluded that inflammation resulting from exhaustive exercise was greater in animals that received macadamia oil than in control animals.
Practical applications: There are potential benefits of using fatty acids in the treatment of injured muscles, and these substances have been used in several types of injured tissues. Macadamia oil intake alters muscle healing signaling by influencing the production of reactive oxygen species and inflammatory mediators. Therefore, it is reasonable to hypothesize that the intake of immunomodulatory supplements would be beneficial to the muscular recovery of an athlete following a strenuous exercise session.
The muscle healing process has three phases: inflammation, new tissue formation and tissue remodeling, and these phases might be modulated by fatty acids. After an exhaustive exercise session, muscle inflammatory markers from macadamia oil‐supplemented rats are augmented in comparison to non‐supplemented animals. Our data revealed increases in the muscle concentrations of IL‐1β, L‐selectin, CINC‐3, and MIP‐3α in the group supplemented with macadamia oil compared with the concentrations in the control group.
Obesity leads to several chronic morbidities including type 2 diabetes, dyslipidemia, atherosclerosis, and hypertension, which are major components of the metabolic syndrome (MetS). Low-grade inflammation has been identified as a key factor in the development of MetS features affecting obese subjects. Several studies have proposed beneficial effects of the omega-3 polyunsaturated fatty acids (n-3 PUFAs) for the prevention and amelioration of MetS features. In this chapter, we will focus on reviewing randomized, controlled trials that evaluate the effects of supplementation with marine-derived EPA and DHA on weight loss, insulin sensitivity, lipid metabolism, blood pressure, and inflammation in overweight/obese subjects with MetS characteristics. Supplementation with n-3 PUFAs may be an interesting therapy to reduce hypertriglyceridemia and hypertension, while the ability of n-3 PUFAs to promote weight loss, insulin sensitivity, and changes in cholesterol metabolism in patients with MetS remains controversial. The role of n-3 PUFAs-derived proresolving lipid mediators such as resolvins, protectins, and maresins in MetS is also discussed.
Objective:
The aim of this study was to analyze whether ω-3 supplementation improves cardiometabolic profile in individuals with cardiovascular risk factors and to determine the effect of adiponectin levels on these changes.
Methods:
In this double-blind, placebo-controlled, 2-mo clinical trial, we randomized 80 individuals of both sexes (mean age 52 y) with at least one cardiovascular risk factor (excess weight, hypertension, dyslipidemia, diabetes, or smoking) into two groups: ω-3 (supplemented with 3 g/d of fish oil containing 37% eicosapentaenoic acid and 23% docosahexaenoic acid) and placebo (3 g/d of sunflower oil containing 65% linoleic acid). At baseline and after the intervention, we evaluated serum adiponectin, leptin, lipid profile, apolipoproteins (apo), electronegative low-density lipoprotein (LDL[-]), and glucose metabolism (glucose and insulin).
Results:
After supplementation, the ω-3 group showed an increase in serum adiponectin. After stratifying the ω-3 group by adiponectin concentration at baseline, participants with lower adiponectin concentration showed a higher reduction of total cholesterol, LDL, LDL/high-density lipoprotein ratio, LDL/apo B, and LDL(-). Individuals with a higher variation of adiponectin concentration after ω-3 supplementation presented with reduced blood glucose. The variation of serum adiponectin induced by ω-3 supplementation was negatively correlated with the Framingham and Adult Treatment Panel IV scores (r = -0.4 and P < 0.05 for both).
Conclusions:
Adiponectin is shown as one of the mechanisms by which ω-3 improves cardiometabolic profile in persons with cardiovascular risk. Moreover, the benefit varies according to the adiponectin basal level and adiponectin variation after supplementation.
Omega-3 PUFA of marine origin reduce adiposity in animals fed a high-fat diet. Our aim was to learn whether EPA and DHA could
limit development of obesity and reduce cellularity of adipose tissue and whether other dietary FA could influence the effect
of EPA/DHA. Weight gain induced by composite high-fat diet in C57BL/6J mice was limited when the content of EPA/DHA was increased
from 1 to 12% (wt/wt) of dietary lipids. Accumulation of adipose tissue was reduced, especially of the epididymal fat. Low
ratio of EPA to DHA promoted the effect. A higher dose of EPA/DHA was required to reduce adiposity when admixed to diets that
did not promote obesity, the semisynthetic high-fat diets rich in EFA, either α-linolenic acid (ALA, 18∶3 n−3, the precursor
of EPA and DHA) or linoleic (18∶2 n−6) acid. Quantification of adipose tissue DNA revealed that except for the diet rich in
ALA the reduction of epididymal fat was associated with 34–50% depression of tissue cellularity, similar to the 30% caloric
restriction in the case of the high-fat composite diet. Changes in plasma markers and adipose gene expression indicated improvement
of lipid and glucose metabolism due to EPA/DHA even in the context of the diet rich in ALA. Our results document augmentation
of the antiadipogenic effect of EPA/DHA during development of obesity and suggest that EPA/DHA could reduce accumulation of
body fat by limiting both hypertrophy and hyperplasia of fat cells. Increased dietary intake of EPA/DHA may be beneficial
regardless of the ALA intake.
The debate over a role for n-3 long-chain polyunsaturated fatty acids (n-3 PUFAs) in depressed mood continues.
The objective was to update a previous systematic review and meta-analysis of published randomized controlled trials investigating the effects of n-3 PUFAs on depressed mood and to explore potential sources of heterogeneity.
Eight databases were searched for trials that randomly assigned participants to receive n-3 PUFAs/fish, measured depressed mood, used human participants, and included a comparison group up to April 2009.
Thirty-five randomized controlled trials were identified; 17 were not included in the previous review. The pooled standardized difference in mean outcome of the 29 trials that provided data to allow pooling (fixed-effects model) was 0.10 SD (95% CI: 0.02, 0.17) in those who received n-3 PUFAs compared with placebo, with strong evidence of heterogeneity (I(2) = 65%, P < 0.01). The presence of funnel plot asymmetry suggested that publication bias was a likely source of this heterogeneity. Depressive symptom severity and participant diagnosis also explained some of the observed heterogeneity. Greater effects of n-3 PUFAs were found in individuals with more-severe depressive symptoms. In trials that enrolled individuals with a diagnosed depressive disorder, the combined mean difference was 0.41 (95% CI: 0.26, 0.55), although evidence of heterogeneity was also found (I(2) = 71%). In trials that enrolled individuals without a depressive diagnosis, no beneficial effects of n-3 PUFAs were found (largest combined mean difference: 0.22; 95% CI: -0.01, 0.44; I(2) = 0%).
Trial evidence of the effects of n-3 PUFAs on depressed mood has increased but remains difficult to summarize because of considerable heterogeneity. The evidence available provides some support of a benefit of n-3 PUFAs in individuals with diagnosed depressive illness but no evidence of any benefit in individuals without a diagnosis of depressive illness.
To examine usual marine omega-3 fatty acid (mO-3FA) intake in individuals with diabetes; its association with adiposity, lipid, and glucose control; and its changes with behavioral lifestyle intervention for weight loss.
Cross-sectional and 1-year longitudinal analyses were performed on 2,397 Look AHEAD (Action for Health in Diabetes) participants. Look AHEAD is a cardiovascular outcome trial evaluating the effects of intensive lifestyle intervention for weight loss in overweight/obese subjects with type 2 diabetes.
Baseline mO-3FA intake was 162 +/- 138 mg/day. It was inversely associated with triglycerides (beta = -0.41, P < 0.001) and weakly with HDL (beta = 4.14, P = 0.050), after multiple covariate adjustment. One-year mO-3FA and fried/sandwich fish intake decreased with intensive lifestyle intervention (P < 0.001).
mO-3FA intake in Look AHEAD participants was low but associated favorably with lipids. These results encourage investigation on the potential benefits of increasing mO-3FA intake in lifestyle interventions for weight loss in individuals with diabetes.
Dropouts and missing data are nearly-ubiquitous in obesity randomized controlled trails, threatening validity and generalizability of conclusions. Herein, we meta-analytically evaluate the extent of missing data, the frequency with which various analytic methods are employed to accommodate dropouts, and the performance of multiple statistical methods.
We searched PubMed and Cochrane databases (2000-2006) for articles published in English and manually searched bibliographic references. Articles of pharmaceutical randomized controlled trials with weight loss or weight gain prevention as major endpoints were included. Two authors independently reviewed each publication for inclusion. 121 articles met the inclusion criteria. Two authors independently extracted treatment, sample size, drop-out rates, study duration, and statistical method used to handle missing data from all articles and resolved disagreements by consensus. In the meta-analysis, drop-out rates were substantial with the survival (non-dropout) rates being approximated by an exponential decay curve (e(-lambdat)) where lambda was estimated to be .0088 (95% bootstrap confidence interval: .0076 to .0100) and t represents time in weeks. The estimated drop-out rate at 1 year was 37%. Most studies used last observation carried forward as the primary analytic method to handle missing data. We also obtained 12 raw obesity randomized controlled trial datasets for empirical analyses. Analyses of raw randomized controlled trial data suggested that both mixed models and multiple imputation performed well, but that multiple imputation may be more robust when missing data are extensive.
Our analysis offers an equation for predictions of dropout rates useful for future study planning. Our raw data analyses suggests that multiple imputation is better than other methods for handling missing data in obesity randomized controlled trials, followed closely by mixed models. We suggest these methods supplant last observation carried forward as the primary method of analysis.
Regular consumption of n-3 fatty acids of marine origin can improve serum lipids and reduce cardiovascular risk.
This study aimed to determine whether eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids have differential effects on serum lipids and lipoproteins, glucose, and insulin in humans.
In a double-blind, placebo-controlled trial of parallel design, 59 overweight, nonsmoking, mildly hyperlipidemic men were randomly assigned to receive 4 g purified EPA, DHA, or olive oil (placebo) daily while continuing their usual diets for 6 wk.
Fifty-six men aged 48.8 +/- 1.1 y completed the study. Relative to those in the olive oil group, triacylglycerols fell by 0.45 +/- 0.15 mmol/L ( approximately 20%; P = 0.003) in the DHA group and by 0.37 +/- 0.14 mmol/L ( approximately 18%; P = 0.012) in the EPA group. Neither EPA nor DHA had any effect on total cholesterol. LDL, HDL, and HDL(2) cholesterol were not affected significantly by EPA, but HDL(3) cholesterol decreased significantly (6.7%; P = 0.032). Although HDL cholesterol was not significantly increased by DHA (3. 1%), HDL(2) cholesterol increased by approximately 29% (P = 0.004). DHA increased LDL cholesterol by 8% (P = 0.019). Adjusted LDL particle size increased by 0.25 +/- 0.08 nm (P = 0.002) with DHA but not with EPA. EPA supplementation increased plasma and platelet phospholipid EPA but reduced DHA. DHA supplementation increased DHA and EPA in plasma and platelet phospholipids. Both EPA and DHA increased fasting insulin significantly. EPA, but not DHA, tended to increase fasting glucose, but not significantly so.
EPA and DHA had differential effects on lipids, fatty acids, and glucose metabolism in overweight men with mild hyperlipidemia.
Epidemiological studies of diet and disease rely on the accurate determination of dietary intake and subsequent estimates of nutrient exposure. Although methodically developed and tested, the instruments most often used to collect self-reported intake data are subject to error. It had been assumed that this error was only random in nature; however, an increasing body of literature suggests that systematic error in the reporting of true dietary intake exists as well. Here, we review studies in which dietary intake by self report was determined while energy expenditure was simultaneously measured using the doubly labeled water (DLW) method. In seeking to establish the relative accuracy of each instrument to capture true habitual energy intake, we conclude that none of the self-reported intake instruments demonstrates greater accuracy against DLW. Instead, it is evident that the physical and psychological characteristics of study participants play a significant role in the underreporting bias observed in these studies. Further research is needed to identify underreporters and to determine how to account for this bias in studies of diet and health.
To review and update the evidence relating to the personal, social, and environmental factors associated with physical activity (PA) in adults.
Systematic review of the peer-reviewed literature to identify papers published between 1998 and 2000 with PA (and including exercise and exercise adherence). Qualitative reports or case studies were not included.
Thirty-eight new studies were located. Most confirmed the existence of factors already known to be correlates of PA. Changes in status were noted in relation to the influence of marital status, obesity, smoking, lack of time, past exercise behavior, and eight environmental variables. New studies were located which focused on previously understudied population groups such as minorities, middle and older aged adults, and the disabled.
The newly reported studies tend to take a broader "ecological" approach to understanding the correlates of PA and are more focused on environmental factors. There remains a need to better understand environmental influences and the factors that influence different types of PA. As most of the work in this field still relies on cross-sectional studies, longitudinal and intervention studies will be required if causal relationships are to be inferred.
Dietary docosahexaenoic acid (DHA) has triacylglycerol-lowering potential and undergoes in vivo retroconversion to eicosapentaenoic acid (EPA) in humans. Hormone replacement therapy (HRT) influences circulating lipid concentrations and fatty acid metabolism. DHA supplementation has not been studied in postmenopausal women.
We studied the effects of supplementation with DHA (free of EPA) on the resulting elevation in EPA and on selected cardiovascular disease risk factors in postmenopausal women.
Women receiving (n = 18) and not receiving (n = 14) HRT completed a randomized, double-blind, placebo-controlled crossover trial with a DHA supplement (2.8 g DHA/d). A washout period of > or =6 wk divided the two 28-d intervention periods. Fasting blood samples were collected for analysis.
In all women, DHA supplementation was associated with significant changes (P < 0.05), including 20% lower serum triacylglycerol concentrations, 8% higher HDL-cholesterol concentrations, a 28% lower overall ratio of serum triacylglycerol to HDL cholesterol, and a 7% decrease in resting heart rate. DHA supplementation resulted in a 45% lower net increase (P = 0.02) in EPA and a 42% lower (P = 0.0028) estimated percentage retroconversion of DHA to EPA [DeltaEPA/(DeltaEPA + DeltaDHA) x 100] in women receiving than in those not receiving HRT.
With DHA supplementation, the accumulation of EPA in serum phospholipids is significantly attenuated in postmenopausal women receiving HRT compared with that in women not receiving HRT. DHA supplementation can also favorably influence selected cardiovascular disease risk factors in postmenopausal women.
Studies suggest eicosapentaenoic acid (EPA), an omega-3 fatty acid, augments weight, appetite, and survival in cancer-associated wasting. This study determined whether an EPA supplement-administered alone or with megestrol acetate (MA)-was more effective than MA.
Four hundred twenty-one assessable patients with cancer-associated wasting were randomly assigned to an EPA supplement 1.09 g administered bid plus placebo; MA liquid suspension 600 mg/d plus an isocaloric, isonitrogenous supplement administered twice a day; or both. Eligible patients reported a 5-lb, 2-month weight loss and/or intake of less than 20 calories/kg/d.
A smaller percentage taking the EPA supplement gained >or= 10% of baseline weight compared with those taking MA: 6% v 18%, respectively (P =.004). Combination therapy resulted in weight gain of >or= 10% in 11% of patients (P =.17 across all arms). The percentage of patients with appetite improvement (North Central Cancer Treatment Group Questionnaire) was not statistically different: 63%, 69%, and 66%, in EPA-, MA-, and combination-treated arms, respectively (P =.69). In contrast, 4-week Functional Assessment of Anorexia/Cachexia Therapy scores suggested MA-containing arms experienced superior appetite stimulation compared with the EPA arm, with scores of 40, 55, and 55 in EPA-, MA-, and combination-treated arms, respectively (P =.004). Survival was not significantly different among arms. Global quality of life was not significantly different among groups. With the exception of increased impotence in MA-treated patients, toxicity was comparable.
This EPA supplement, either alone or in combination with MA, does not improve weight or appetite better than MA alone.
To investigate whether the substitution of fish oil for visible fats in a control diet (52% carbohydrates, 16% protein, 32% fat; P:S 0.2) influences body fat mass and substrate oxidation in healthy adults.
Six volunteers (5 men; 23 +/- 2 y; BMI: 21.9 +/- 1.6) were fed a control diet (C) ad libitum during a period of three weeks and, 10-12 weeks later, the same diet where 6 g/d of visible fat were replaced by 6 g/d of fish oil (FO) for another three weeks.
Energy intakes (IKA-calorimeter) were unchanged. Body fat mass (Dual-energy X-ray absorptiometry) decreased with FO (-0.88 +/- 0.16 vs -0.3 +/- 0.34 kg; FO vs C; P < 0.05). When adjusted for lean body mass (Ancova), resting metabolic rate (indirect calorimetry) was unchanged. Basal respiratory quotient decreased with FO (0.815 +/- 0.02 vs 0.834 +/- 0.02; P < 0.05) and basal lipid oxidation increased with FO (1.06 +/- 0.17 vs 0.87 +/- 0.13 mg kg(-1) min(-1); P < 0.05).
Dietary FO reduces body fat mass and stimulates lipid oxidation in healthy adults.
Polyunsaturated fatty acids of n-3 series (n-3 PUFA) were shown to increase basal fat oxidation in humans. The aim of the study was to compare the effect of n-3 PUFA added to a very low calorie diet (VLCD), with VLCD only during three-week inpatient weight reduction. Twenty severely obese women were randomly assigned to VLCD with n-3 PUFA or with placebo. Fatty acids in serum lipid fractions were quantified by gas chromatography. Differences between the groups were determined using ANOVA. Higher weight (7.55+/-1.77 vs. 6.07+/-2.16 kg, NS), BMI (2.82+/-0.62 vs. 2.22+/-0.74, p<0.05) and hip circumference losses (4.8+/-1.81 vs. 2.5+/-2.51 cm, p<0.05) were found in the n-3 group as compared to the control group. Significantly higher increase in beta-hydroxybutyrate was found in the n-3 group showing higher ketogenesis and possible higher fatty acid oxidation. The increase in beta-hydroxybutyrate significantly correlated with the increase in serum phospholipid arachidonic acid (20:4n-6; r = 0.91, p<0.001). In the n-3 group significantly higher increase was found in n-3 PUFA (eicosapentaenoic acid, 20:5n-3, docosahexaenoic acid, 22:6n-3) in triglycerides and phospholipids. The significant decrease of palmitoleic acid (16:1n-7) and vaccenic acid (18:1n-7) in triglycerides probably reflected lower lipogenesis. A significant negative correlation between BMI change and phospholipid docosahexaenoic acid change was found (r = -0.595, p<0.008). The results suggest that long chain n-3 PUFA enhance weight loss in obese females treated by VLCD. Docosahexaenoate (22:6n-3) seems to be the active component.
Diets rich in n-3 polyunsaturated fatty acids, namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), protect against insulin resistance and obesity in rodents and increase insulin sensitivity in healthy humans. We tested whether the anti-diabetic effects of EPA and DHA involve enhanced production of the endogenous insulin sensitiser, adiponectin.
We studied the effects, in an obesity-promoting high-fat diet, of partial replacement of vegetable oils by EPA/DHA concentrate (6% EPA, 51% DHA) over a 5-week period in adult male C57BL/6J mice that either had free access to food or had their food intake restricted by 30%. At the end of the treatment, systemic markers of lipid and glucose metabolism and full-length adiponectin and leptin were measured. Adiponectin (Adipoq) and leptin (Lep) gene expression in dorsolumbar and epididymal white adipose tissue (WAT) and isolated adipocytes was quantified and adipokine production from WAT explants evaluated.
In mice with free access to food, plasma triacylglycerols, NEFA, and insulin levels were lower in the presence of EPA/DHA, while glucose and leptin levels were not significantly altered. Food restriction decreased plasma triacylglycerols, glucose, insulin and leptin, but not adiponectin. EPA/DHA increased plasma adiponectin levels, independent of food intake, reflecting the stimulation of Adipoq expression in adipocytes and the release of adiponectin from WAT, particularly from epididymal fat. Expression of Lep and the release of leptin from WAT, while being extremely sensitive to caloric restriction, was unaltered by EPA/DHA.
Intake of diets rich in EPA and DHA leads to elevated systemic concentrations of adiponectin, largely independent of food intake or adiposity and explain, to some extent, their anti-diabetic effects.
n-3 PUFA have shown potential anti-obesity and insulin-sensitising properties. However, the mechanisms involved are not clearly established. The aim of the present study was to assess the effects of EPA administration, one of the n-3 PUFA, on body-weight gain and adiposity in rats fed on a standard or a high-fat (cafeteria) diet. The actions on white adipose tissue lipolysis, apoptosis and on several genes related to obesity and insulin resistance were also studied. Control and cafeteria-induced overweight male Wistar rats were assigned into two subgroups, one of them daily received EPA ethyl ester (1 g/kg) for 5 weeks by oral administration. The high-fat diet induced a very significant increase in both body weight and fat mass. Rats fed with the cafeteria diet and orally treated with EPA showed a marginally lower body-weight gain (P = 0.09), a decrease in food intake (P < 0.01) and an increase in leptin production (P < 0.05). EPA administration reduced retroperitoneal adipose tissue weight (P < 0.05) which could be secondary to the inhibition of the adipogenic transcription factor PPARgamma gene expression (P < 0.001), and also to the increase in apoptosis (P < 0.05) found in rats fed with a control diet. TNFalpha gene expression was significantly increased (P < 0.05) by the cafeteria diet, while EPA treatment was able to prevent (P < 0.01) the rise in this inflammatory cytokine. Adiposity-corrected adiponectin plasma levels were increased by EPA. These actions on both TNFalpha and adiponectin could explain the beneficial effects of EPA on insulin resistance induced by the cafeteria diet.
Use of n-3 fatty acids (FA) has been reported to be beneficial for cancer patients. We performed a systematic review of the literature in order to issue recommendations on the clinical use of n-3 FA in the cancer setting. A systematic search was performed in MEDLINE, EMBASE, Cochrane and Healthstar databases. We selected clinical trials or prospective observational studies including patients with cancer and life expectancy >2 months, in which enteral supplements with n-3 FA were administered. Parameters evaluated individually were clinical (nutritional status, tolerance, survival and hospital stays), biochemical (inflammatory mediators), and functional (functional status, appetite and quality of life (QoL)). Seventeen studies met the inclusion criteria; eight were of high quality. The panel of experts established the following evidence: (1) oral supplements with n-3 FA benefit patients with advanced cancer and weight loss, and are indicated in tumours of the upper digestive tract and pancreas; (2) the advantages observed were: increased weight and appetite, improved QoL, and reduced post-surgical morbidity; (3) there is no defined pattern for combining different n-3 FA, and it is recommended to administer > 1.5 g/day; and (4) better tolerance is obtained administering low-fat formulas for a period of at least 8 weeks. All the evidences were grade B but for 'length of treatment' and 'advantage of survival' it was grade C. Our findings suggest that administration of n-3 FA (EPA and DHA) in doses of at least 1.5 g/day for a prolonged period of time to patients with advanced cancer is associated with an improvement in clinical, biological and QoL parameters.
To investigate the effect of including seafood and fish oils, as part of an energy-restricted diet, on weight loss in young overweight adults.
Randomized controlled trial of energy-restricted diet varying in fish and fish oil content was followed for 8 weeks. Subjects were randomized to one of four groups: (1) control (sunflower oil capsules, no seafood); (2) lean fish (3 x 150 g portions of cod/week); (3) fatty fish (3 x 150 g portions of salmon/week); (4) fish oil (DHA/EPA capsules, no seafood). The macronutrient composition of the diets was similar between the groups and the capsule groups, were single-blinded.
A total of 324 men and women aged 20-40 years, BMI 27.5-32.5 kg/m(2) from Iceland, Spain and Ireland.
Anthropometric data were collected at baseline, midpoint and endpoint. Confounding factors were accounted for, with linear models, for repeated measures with two-way interactions. The most important interactions for weight loss were (diet x energy intake), (gender x diet) and (gender x initial-weight).
An average man in the study (95 kg at baseline receiving 1600 kcal/day) was estimated to lose 3.55 kg (95% CI, 3.14-3.97) (1); 4.35 kg (95% CI, 3.94-4.75) (2); 4.50 kg (95% CI, 4.13-4.87) (3) and 4.96 kg (95% CI, 4.53-5.40) on diet (4) in 4 weeks, from baseline to midpoint. The weight-loss from midpoint to endpoint was 0.45 (0.41-0.49) times the observed weight loss from baseline to midpoint. The diets did not differ in their effect on weight loss in women. Changes in measures of body composition were in line with changes in body weight.
In young, overweight men, the inclusion of either lean or fatty fish, or fish oil as part of an energy-restricted diet resulted in approximately 1 kg more weight loss after 4 weeks, than did a similar diet without seafood or supplement of marine origin. The addition of seafood to a nutritionally balanced energy-restricted diet may boost weight loss.
To assist health professionals who counsel patients with overweight and obesity, a systematic review was undertaken to determine types of weight-loss interventions that contribute to successful outcomes and to define expected weight-loss outcomes from such interventions.
A search was conducted for weight-loss-focused randomized clinical trials with >or=1-year follow-up. Eighty studies were identified and are included in the evidence table.
The primary outcomes were a measure of weight loss at 6, 12, 24, 36, and 48 months. Eight types of weight-loss interventions-diet alone, diet and exercise, exercise alone, meal replacements, very-low-energy diets, weight-loss medications (orlistat and sibutramine), and advice alone-were identified. By using simple pooling across studies, subjects mean amount of weight loss at each time point for each intervention was determined.
Efficacy outcomes were calculated by meta-analysis and provide support for the pooled data. Hedges' gu was combined across studies to obtain an average effect size (and confidence level).
A mean weight loss of 5 to 8.5 kg (5% to 9%) was observed during the first 6 months from interventions involving a reduced-energy diet and/or weight-loss medications with weight plateaus at approximately 6 months. In studies extending to 48 months, a mean 3 to 6 kg (3% to 6%) of weight loss was maintained with none of the groups experiencing weight regain to baseline. In contrast, advice-only and exercise-alone groups experienced minimal weight loss at any time point.
Weight-loss interventions utilizing a reduced-energy diet and exercise are associated with moderate weight loss at 6 months. Although there is some regain of weight, weight loss can be maintained. The addition of weight-loss medications somewhat enhances weight-loss maintenance.
Information is lacking on the potential effect of n-3 polyunsaturated fatty acids (PUFAs) on the adipose tissue of patients with type 2 diabetes.
We evaluated whether n-3 PUFAs have additional effects on adiposity, insulin sensitivity, adipose tissue function (production of adipokines and inflammatory and atherogenic factors), and gene expression in type 2 diabetes.
Twenty-seven women with type 2 diabetes without hypertriglyceridemia were randomly allocated in a double-blind parallel design to 2 mo of 3 g/d of either fish oil (1.8 g n-3 PUFAs) or placebo (paraffin oil).
Although body weight and energy intake measured by use of a food diary were unchanged, total fat mass (P < 0.019) and subcutaneous adipocyte diameter (P < 0.0018) were lower in the fish oil group than in the placebo group. Insulin sensitivity was not significantly different between the 2 groups (measured by homeostasis model assessment in all patients and by euglycemic-hyperinsulinemic clamp in a subgroup of 5 patients per group). By contrast, atherogenic risk factors, including plasma triacylglycerol (P < 0.03), the ratio of triacylglycerol to HDL cholesterol (atherogenic index, P < 0.03), and plasma plasminogen activator inhibitor-1 (P < 0.01), were lower in the fish oil group than in the placebo group. In addition, a subset of inflammation-related genes was reduced in subcutaneous adipose tissue after the fish oil, but not the placebo, treatment.
A moderate dose of n-3 PUFAs for 2 mo reduced adiposity and atherogenic markers without deterioration of insulin sensitivity in subjects with type 2 diabetes. Some adipose tissue inflammation-related genes were also reduced. These beneficial effects could be linked to morphologic and inflammatory changes in adipose tissue. This trial was registered at clinicaltrials.gov as NCT0037.
Activity energy expenditure (AEE) is the modifiable component of total energy expenditure (TEE) derived from all activities, both volitional and nonvolitional. Because AEE may affect health, there is interest in its estimation in free-living people. Physical activity questionnaires (PAQs) could be a feasible approach to AEE estimation in large populations, but it is unclear whether or not any PAQ is valid for this purpose. Our aim was to explore the validity of existing PAQs for estimating usual AEE in adults, using doubly labeled water (DLW) as a criterion measure. We reviewed 20 publications that described PAQ-to-DLW comparisons, summarized study design factors, and appraised criterion validity using mean differences (AEE(PAQ) - AEE(DLW), or TEE(PAQ) - TEE(DLW)), 95% limits of agreement, and correlation coefficients (AEE(PAQ) versus AEE(DLW) or TEE(PAQ) versus TEE(DLW)). Only 2 of 23 PAQs assessed most types of activity over the past year and indicated acceptable criterion validity, with mean differences (TEE(PAQ) - TEE(DLW)) of 10% and 2% and correlation coefficients of 0.62 and 0.63, respectively. At the group level, neither overreporting nor underreporting was more prevalent across studies. We speculate that, aside from reporting error, discrepancies between PAQ and DLW estimates may be partly attributable to 1) PAQs not including key activities related to AEE, 2) PAQs and DLW ascertaining different time periods, or 3) inaccurate assignment of metabolic equivalents to self-reported activities. Small sample sizes, use of correlation coefficients, and limited information on individual validity were problematic. Future research should address these issues to clarify the true validity of PAQs for estimating AEE.
Epidemiological research indicates that long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) improve insulin resistance. The aim of this study was to investigate the effects of seafood consumption on insulin resistance in overweight participants during energy restriction.
In this 8 week dietary intervention, 324 participants (20-40 years, BMI 27.5-32.5 kg/m(2), from Iceland, Spain and Ireland) were randomised by computer to one of four energy-restricted diets (-30E%) of identical macronutrient composition but different LC n-3 PUFA content: control (n = 80; no seafood; single-blinded); lean fish (n = 80; 150 g cod, three times/week); fatty fish (n = 84; 150 g salmon, three times/week); (4) fish oil (n = 80; daily docosahexaenoic/eicosapentaenoic acid capsules, no other seafood; single-blinded). Fasting glucose, insulin, adiponectin, plasma triacylglycerol and fatty acids in erythrocyte membrane were measured at baseline and endpoint. Insulin resistance was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR). Linear models with fixed effects and covariates were used to investigate the effects of seafood consumption on fasting insulin and HOMA-IR at endpoint in comparison with the control group.
Of the participants, 278 (86%) completed the intervention. Fish oil intake was a significant predictor of fasting insulin and insulin resistance after 8 weeks, and this finding remained significant even after including weight loss, triacylglycerol reduction, increased LC n-3 PUFA in membranes or adiponectin changes as covariates in the statistical analysis. Weight loss was also a significant predictor of improvements.
LC n-3 PUFA consumption during energy reduction exerts positive effects on insulin resistance in young overweight individuals, independently from changes in body weight, triacylglycerol, erythrocyte membrane or adiponectin.
ClinicalTrials.gov NCT00315770.
Background: Information is lacking on the potential effect of n−3 polyunsaturated fatty acids (PUFAs) on the adipose tissue of patients with type 2 diabetes.
Objective: We evaluated whether n−3 PUFAs have additional effects on adiposity, insulin sensitivity, adipose tissue function (production of adipokines and inflammatory and atherogenic factors), and gene expression in type 2 diabetes.
Design: Twenty-seven women with type 2 diabetes without hypertriglyceridemia were randomly allocated in a double-blind parallel design to 2 mo of 3 g/d of either fish oil (1.8 g n−3 PUFAs) or placebo (paraffin oil).
Results: Although body weight and energy intake measured by use of a food diary were unchanged, total fat mass (P < 0.019) and subcutaneous adipocyte diameter (P < 0.0018) were lower in the fish oil group than in the placebo group. Insulin sensitivity was not significantly different between the 2 groups (measured by homeostasis model assessment in all patients and by euglycemic-hyperinsulinemic clamp in a subgroup of 5 patients per group). By contrast, atherogenic risk factors, including plasma triacylglycerol (P < 0.03), the ratio of triacylglycerol to HDL cholesterol (atherogenic index, P < 0.03), and plasma plasminogen activator inhibitor-1 (P < 0.01), were lower in the fish oil group than in the placebo group. In addition, a subset of inflammation-related genes was reduced in subcutaneous adipose tissue after the fish oil, but not the placebo, treatment.
Conclusions: A moderate dose of n−3 PUFAs for 2 mo reduced adiposity and atherogenic markers without deterioration of insulin sensitivity in subjects with type 2 diabetes. Some adipose tissue inflammation-related genes were also reduced. These beneficial effects could be linked to morphologic and inflammatory changes in adipose tissue. This trial was registered at clinicaltrials.gov as NCT0037.
This is the protocol for a review and there is no abstract. The objectives are as follows:
The objective of this review will be to determine the effectiveness of fish oils, containing eicosapentaenoic acid, to decrease weight loss, increase duration of survival and improve quality of life for those patients with incurable cancer and cachexia.
Lipid decomposition studies in frozen fish have led to the development of a simple and rapid method for the extraction and purification of lipids from biological materials. The entire procedure can be carried out in approximately 10 minutes; it is efficient, reproducible, and free from deleterious manipulations. The wet tissue is homogenized with a mixture of chloroform and methanol in such proportions that a miscible system is formed with the water in the tissue. Dilution with chloroform and water separates the homogenate into two layers, the chloroform layer containing all the lipids and the methanolic layer containing all the non-lipids. A purified lipid extract is obtained merely by isolating the chloroform layer. The method has been applied to fish muscle and may easily be adapted to use with other tissues.
Background: Dietary docosahexaenoic acid (DHA) has triacylglycerol-lowering potential and undergoes in vivo retroconversion to eicosapentaenoic acid (EPA) in humans. Hormone replacement therapy (HRT) influences circulating lipid concentrations and fatty acid metabolism. DHA supplementation has not been studied in postmenopausal women. Objective: We studied the effects of supplementation with DHA (free of EPA) on the resulting elevation in EPA and on selected cardiovascular disease risk factors in postmenopausal women. Design: Women receiving (n = 18) and not receiving (n = 14) HRT completed a randomized, double-blind, placebo-controlled cross-over trial with a DHA supplement (2.8 g DHA/d). A washout period of ≥ 6 wk divided the two 28-d intervention periods. Fasting blood samples were collected for analysis. Results: In all women, DHA supplementation was associated with significant changes (P < 0.05), including 20% lower serum triacylglycerol concentrations, 8% higher HDL-cholesterol concentrations, a 28% lower overall ratio of serum triacylglycerol to HDL cholesterol, and a 7% decrease in resting heart rate. DHA supplementation resulted in a 45% lower net increase (P = 0.02) in EPA and a 42% lower (P = 0.0028) estimated percentage retroconversion of DHA to EPA [ΔEPA/ (ΔEPA + ΔDHA) X 100] in women receiving than in those not receiving HRT. Conclusion: With DHA supplementation, the accumulation of EPA in serum phospholipids is significantly attenuated in postmenopausal women receiving HRT compared with that in women not receiving HRT. DHA supplementation can also favorably influence selected cardiovascular disease risk factors in postmenopausal women.
Background: Regular exercise and consuming long-chain n-3 fatty acids (FAs) from fish or fish oil can independently improve cardiovascular and metabolic health, but combining these lifestyle modifications may be more effective than either treatment alone. Objective: We examined the individual and combined effects of n-3 FA supplements and regular exercise on body composition and cardiovascular health. Design: Overweight volunteers [body mass index (BMI; in kg/m2): >25] with high blood pressure, cholesterol, or triacylglycerols were randomly assigned to one of the following interventions: fish oil (FO), FO and exercise (FOX), sunflower oil (SO; control), or SO and exercise (SOX). Subjects consumed 6 g tuna FO/d (≈1.9 g n-3 FA) or 6 g SO/d. The exercise groups walked 3 d/wk for 45 min at 75% age-predicted maximal heart rate. Plasma lipids, blood pressure, and arterial function were assessed at 0, 6, and 12 wk. Body composition was assessed by dual-energy X-ray absorptiometry at 0 and 12 wk only. Results: FO supplementation lowered triacylglycerols, increased HDL cholesterol, and improved endothelium-dependent arterial vasodilation (P < 0.05). Exercise improved arterial compliance (P < 0.05). Both fish oil and exercise independently reduced body fat (P < 0.05). Conclusions: FO supplements and regular exercise both reduce body fat and improve cardiovascular and metabolic health. Increasing intake of n-3 FAs could be a useful adjunct to exercise programs aimed at improving body composition and decreasing cardiovascular disease risk.
Omega-3 fatty acid (n-3 FA) blood levels and intake have been inversely associated with risk for sudden cardiac death, but their relationship with all-cause mortality is unclear. The purpose of this study was to determine the extent to which baseline blood n-3 FA levels are associated with reduced risk for all-cause mortality in patients with stable coronary heart disease.
The Heart and Soul study used a prospective cohort design with a median follow-up of 5.9 years. Patients were recruited between 2000 and 2002 from 12 outpatient facilities in the San Francisco Bay Area. Standard cardiovascular risk factors, demographics, socioeconomic status, health behaviors, and inflammatory markers were collected at baseline. Fasting blood levels of eicosapentaenoic and docosahexaenoic acids were measured and expressed as a percent of total blood FAs. Vital status was assessed with annual telephone interviews and confirmed by review of death certificates. There were 237 deaths among 956 patients. Cox proportional hazards models were used to evaluate the extent to which blood eicosapentaenoic and docosahexaenoic acids were independently associated with all cause mortality. Compared with patients having baseline eicosapentaenoic and docosahexaenoic acids levels below the median (<3.6%), those at or above the median had a 27% decreased risk of death (hazard ratio, 0.73; 95% confidence interval, 0.56-0.94). This association was unaffected by adjustment for age, sex, ethnicity, center, socioeconomic status, traditional cardiovascular risk factors, and inflammatory markers (hazard ratio, 0.74; 95% confidence interval, 0.55-1.00, P<0.05).
In these outpatients with stable coronary heart disease, blood n-3 FA levels were inversely associated with total mortality independent of standard and emerging risk factors, suggesting that reduced tissue n-3 FA levels may adversely impact metabolism.
Animal studies suggest that increased consumption of the long-chain omega-3 polyunsaturated fatty acids, eicosapentaenoic acid and docosahexaenoic acid, can protect against the development of obesity in animals exposed to an obesogenic diet and reduce body fat when already obese. There is also evidence that increased intakes of these fatty acids can reduce body fat in humans, but human studies are relatively few and have generally been conducted over short time periods with small sample sizes, making it difficult to draw definitive conclusions. Reported reductions in body fat may result from appetite-suppressing effects, adipocyte apoptosis and changes of gene expression in skeletal muscle, heart, liver, intestine and adipose tissues that suppress fat deposition and increase fat oxidation and energy expenditure. We conclude that increased intakes of long-chain omega-3 fatty acids may improve body composition, but longer-term human studies are needed to confirm efficacy and determine whether increasing omega-3 intakes might be an effective strategy to combat obesity.
The National Cholesterol Education Program (NCEP) recommends a low-saturated-fat, low-cholesterol diet, with weight loss if indicated, to correct elevated plasma cholesterol levels. Weight loss accomplished by simple caloric restriction or increased exercise typically increases the level of high-density lipoprotein (HDL) cholesterol. Little is known about the effects on plasma lipoproteins of a hypocaloric NCEP diet with or without exercise in overweight people.
We tested the hypothesis that exercise (walking or jogging) will increase HDL cholesterol levels in moderately overweight, sedentary people who adopt a hypocaloric NCEP diet. We randomly assigned 132 men and 132 women 25 to 49 years old to one of three groups: control, hypocaloric NCEP diet, or hypocaloric NCEP diet with exercise. One hundred nineteen of the men and 112 of the women returned for testing after one year.
After one year, the subjects in both intervention groups had reached or closely approached NCEP Step 1 dietary goals and reduced their mean body fat significantly (range of reduction in mean fat weight, 4.0 to 7.8 kg). Weight loss on the NCEP diet alone did not significantly change HDL cholesterol levels in either the men or the women as compared with the subjects in the control group. Plasma levels of HDL cholesterol increased significantly more in the men who exercised and dieted (mean [+/- SE] change, +13 +/- 3 percent) than in the men who only dieted (+2 +/- 3 percent, P less than 0.01) or the men who acted as controls (-4 +/- 2 percent, P less than 0.001). HDL cholesterol levels remained about the same in the women who exercised and dieted (+1 +/- 2 percent); they were higher than in the women who only dieted (-10 +/- 3 percent, P less than 0.01), but not higher than in the controls (-3 +/- 3 percent).
Regular exercise in overweight men and women enhances the improvement in plasma lipoprotein levels that results from the adoption of a low-saturated-fat, low-cholesterol diet.
This investigation determined the accuracy of self-reports of physical activity compared to observations obtained surreptitiously. Subjects were 44 adults engaged in 1 h of their preferred physical activity while actual activity levels were surreptitiously obtained and compared to immediate self-reported estimates of physical activity. Results indicated that subjects were moderately accurate in recalling their physical activity levels (R = 0.62) but underestimated sedentary activities and overestimated aerobic activities by over 300%. Males overestimated their activity relative to females, and obese subjects underestimated their activity levels compared to normal-weight subjects. Finally, a number of two-way interactions that moderated the accuracy of those subjects engaging in high chronic levels of physical activity were observed.
Because both aerobic exercise and fish oil ingestion have been shown to decrease plasma lipids, we examined the effects of combining these modalities in hyperlipidemic subjects. Thirty-four subjects were randomly assigned to one of four groups as follows: fish oil and exercise (FE), N = 7, 50 ml of oil daily and 3 d.wk-1 of aerobic exercise; fish oil (F), N = 7, 50 ml of oil daily; corn oil (CN), N = 10, 50 ml of oil daily; and control (C), N = 10. Blood samples were drawn at baseline and at the end of 4, 8, and 12 wk. The FE and F groups showed significantly lower triglycerides with respect to treatment as compared to the CN and C groups. The FE, F, and CN groups exhibited lower total cholesterol values than the control group but were not different from each other. HDL cholesterol was significantly increased after treatment in the FE and F groups as compared to the CN and C groups. Serum apo-B, LDL cholesterol, and LDL protein decreased significantly in the FE group but not the F group from baseline to 12 wk. VO2max increased and percent fat decreased only in the FE group. In conclusion, aerobic exercise improved the effects of fish oil on LDL cholesterol and apo-B and improved fitness and body composition in hyperlipidemic subjects.
Obesity is a major factor contributing to hypertension and increased risk of cardiovascular disease. Regular consumption of dietary fish and omega3 fatty acids of marine origin can lower blood pressure (BP) levels and reduce cardiovascular risk. This study examined the potential effects of combining dietary fish rich in omega3 fatty acids with a weight loss regimen in overweight hypertensive subjects, with ambulatory BP levels as the primary end point. Using a factorial design, 69 overweight medication-treated hypertensives were randomized to a daily fish meal (3.65 g omega3 fatty acids), weight reduction, the 2 regimens combined, or a control regimen for 16 weeks. Sixty-three subjects with a mean+/-SEM body mass index of 31.6+/-0.5 kg/m2 completed the study. Weight fell by 5.6+/-0.8 kg with energy restriction. Dietary fish and weight loss had significant independent and additive effects on 24-hour ambulatory BP. Effects were greatest on awake systolic and diastolic BP (P<0.01); relative to control, awake pressures fell 6.0/3.0 mm Hg with dietary fish alone, 5.5/2.2 mm Hg with weight reduction alone, and 13.0/9.3 mm Hg with fish and weight loss combined. These results also remained significant after further adjustment for changes in urinary sodium, potassium, or the sodium/potassium ratio, as well as dietary macronutrients. Dietary fish also significantly reduced 24-hour (-3.1+/-1.4 bpm, P=0.036) and awake (-4.2+/-1.6 bpm, P=0. 013) ambulatory heart rates. Weight reduction had a significant effect on sleeping heart rate only (-3.2+/-1.7 bpm, P=0.037). Combining a daily fish meal with a weight-reducing regimen led to additive effects on ambulatory BP and decreased heart rate. The effects were large, suggesting that cardiovascular risk and antihypertensive drug requirements are likely to be reduced substantially by combining dietary fish meals rich in omega3 fatty acids with weight-loss regimens in overweight medication-treated hypertensives. The reduction in heart rate seen with dietary fish suggests a cardiac/autonomic component, as well as vascular effects, of increased consumption of omega3 fatty acid from fish.
Rats fed dietary fats rich in 20- and 22-carbon polyenoic fatty acids deposit less fat and expend more energy at rest than rats fed other types of fats. We hypothesized that this decrease in energetic efficiency was the product of: (a) enhanced peroxisomal fatty acid oxidation and/or (b) the up-regulation of genes encoding proteins that were involved with enhanced heat production, i.e. mitochondrial uncoupling proteins (UCP-2, UCP-3) and peroxisomal fatty acid oxidation proteins. Two groups of male Fisher 344 rats 3-4 week old (n=5 per group) were pair fed for 6 weeks a diet containing 40% of its energy fat derived from either fish oil or corn oil. Epididymal fat pads from rats fed the fish oil diet weighed 25% (P < 0.05) less than those found in rats fed corn oil. The decrease in fat deposition associated with fish oil ingestion was accompanied by a significant increase in the abundance of skeletal muscle UCP-3 mRNA. The level of UCP-2 mRNA skeletal muscle was unaffected by the type of dietary oil, but the abundance of UCP-2 mRNA in the liver and heart were significantly lower (P < 0.05) in rats fed fish oil than in rats fed corn oil. In addition to inducing UCP-3 expression, dietary fish oil induced peroxisomal acyl-CoA oxidase gene expression 2-3 fold in liver, skeletal muscle and heart. These data support the hypothesis that dietary fish oil reduces fat deposition by increasing the expression of mitochondrial uncoupling proteins and increasing fatty acid oxidation by the less efficient peroxisomal pathway.
Obesity in hypertensive patients is associated with dyslipidemia and insulin resistance, both of which are improved by weight control. n-3 Fatty acids have diverse effects on mechanisms underlying atherosclerosis, including a decrease in serum triacylglycerols and an increase in HDL(2) cholesterol.
The objective was to examine whether dietary fish enhances the effects of weight loss on serum lipids, glucose, and insulin in 69 overweight, treated hypertensive patients.
Overweight patients being treated for hypertension were randomly assigned to either a daily fish meal (3.65 g n-3 fatty acids), a weight-loss regimen, the 2 regimens combined, or a control group for 16 wk.
Sixty-three subjects completed the study. Weight decreased by a mean (+/-SEM) of 5.6 +/- 0.8 kg with energy restriction. Weight loss decreased fasting insulin (P = 0.003) and the area under the curve for insulin (P = 0.003) and glucose (P = 0.047) during an oral-glucose-tolerance test. The greatest decrease occurred in the fish + weight-loss group. There was no independent effect of fish on glucose or insulin. Fish increased HDL(2) cholesterol (P = 0.004) and decreased HDL(3) cholesterol (P = 0.026) without altering total, LDL, or HDL cholesterol. Weight loss had no effect on these variables. Fasting triacylglycerols fell significantly with fish consumption (29%) and weight loss (26%). The fish + weight-loss group showed the greatest improvement in lipids: triacylglycerols decreased by 38% (P < 0.001) and HDL(2) cholesterol increased by 24% (P = 0.04) compared with the control group.
Incorporating a daily fish meal into a weight-loss regimen was more effective than either measure alone at improving glucose-insulin metabolism and dyslipidemia. Cardiovascular risk is likely to be substantially reduced in overweight hypertensive patients with a weight-loss program incorporating fish meals rich in n-3 fatty acids.
We examined the effect of dietary fats rich in n-3 polyunsaturated fatty acids (PUFA) on mRNA levels in white and brown adipose tissues in rats. Four groups of rats were fed on a low-fat diet (20 g safflower oil/kg) or a high-fat diet (200 g/kg) containing safflower oil, which is rich in n-6 PUFA (linoleic acid), or perilla (alpha-linolenic acid) or fish oil (eicosapentaenoic and docosahexaenoic acids), both of which are rich in n-3 PUFA, for 21 d. Energy intake was higher in rats fed on a high-safflower-oil diet than in those fed on low-fat or high-fish-oil diet, but no other significant differences were detected among the groups. Perirenal white adipose tissue weight was higher and epididymal white adipose tissue weight tended to be higher in rats fed on a high-safflower-oil diet than in those fed on a low-fat diet. However, high-fat diets rich in n-3 PUFA, compared to a low-fat diet, did not increase the white adipose tissue mass. High-fat diets relative to a low-fat diet increased brown adipose tissue uncoupling protein 1 mRNA level. The increases were greater with fats rich in n-3 PUFA than with n-6 PUFA. A high-safflower-oil diet, compared to a low-fat diet, doubled the leptin mRNA level in white adipose tissue. However, high-fat diets rich in n-3 PUFA failed to increase it. Compared to a low-fat diet, high-fat diets down-regulated the glucose transporter 4 mRNA level in white adipose tissue. However, the decreases were attenuated with high-fat diets rich in n-3 PUFA. It is suggested that the alterations in gene expression in adipose tissue contribute to the physiological activities of n-3 PUFA in preventing body fat accumulation and in regulating glucose metabolism in rats.
Epidemiologic evidence shows an inverse relation between fish consumption and death from ischemic heart disease. This beneficial effect is attributed to n-3 fatty acids.
The purpose of this study was to examine the association between plasma phospholipid concentrations of the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and various cardiovascular disease risk factors among Quebecers.
The study population consisted of 1460 subjects aged 18-74 y who participated in the 1990 Quebec Heart Health and Nutrition Survey. Data were obtained through home interviews and clinic visits.
Expressed as the percentage of total fatty acids in plasma phospholipids, the geometric means of EPA, DHA, and their combination were 0.47%, 1.19%, and 1.70%, respectively. Concentrations of n-3 fatty acids were positively associated with fish intake. We found positive associations between EPA and total cholesterol, LDL cholesterol, HDL cholesterol, plasma glucose, and systolic and diastolic blood pressure. We found positive associations between DHA and total cholesterol, the ratio of total to HDL cholesterol, triacylglycerols, systolic blood pressure, and plasma glucose and insulin. We also found positive associations between the ratio of EPA to arachidonic acid and total cholesterol, HDL cholesterol, and systolic blood pressure and a negative association with the ratio of total to HDL cholesterol.
Our results indicate that concentrations of EPA and DHA in plasma phospholipids reflected Quebecer fish consumption. Results also show that EPA and the ratio of EPA to arachidonic acid can positively influence HDL-cholesterol concentrations.
The Depression Outcomes Study of Exercise (DOSE) was a randomized clinical trial to determine whether exercise is an efficacious treatment for mild to moderate major depressive disorder (MDD) in adults ages 20 to 45 years. The specific hypotheses under investigation were (1) active exercise is an efficacious monotherapy for mild to moderate levels of MDD, and (2) there is a dose-response relation between the exercise amount and reduction in depressive symptoms. The primary outcome measure was the Hamilton Rating Scale for Depression (HRSD) collected weekly over 12 weeks. Secondary outcome measures were the Inventory of Depressive Symptoms (clinician and self-report), HRSD scores at 24 weeks, cardiorespiratory fitness, self-efficacy, and quality of life. Eighty men and women who were diagnosed with a Structured Clinical Interview for Depression and who had mild (HRSD 12-16) to moderate (HRSD 17-25) MDD were randomized to one of five doses of exercise: 7.0 kcal/kg/week in 3 days/week; 7.0 kcal/kg/week in 5 days/week; 17.5 kcal/kg/week in 3 days/week; 17.5 kcal/kg/week in 5 days/week; or 3 days/week of stretching and flexibility exercises for 15 to 20 min/session. Participants exercised under supervision in our laboratory over the course of 12 weeks. Symptoms of depression were measured weekly by trained clinical raters blinded to the participant's treatment assignment. The design of the study restricted participant characteristics to mild to moderate MDD and controlled exercise features to permit the evaluation of exercise as a sole treatment for depression. This study is the first to examine dose-response effects of exercise in participants diagnosed with MDD.
Lipid decomposition studies in frozen fish have led to the development of a simple and rapid method for the extraction and purification of lipids from biological materials. The entire procedure can be carried out in approximately 10 minutes; it is efficient, reproducible, and free from deleterious manipulations. The wet tissue is homogenized with a mixture of chloroform and methanol in such proportions that a miscible system is formed with the water in the tissue. Dilution with chloroform and water separates the homogenate into two layers, the chloroform layer containing all the lipids and the methanolic layer containing all the non-lipids. A purified lipid extract is obtained merely by isolating the chloroform layer. The method has been applied to fish muscle and may easily be adapted to use with other tissues.Lipid decomposition studies in frozen fish have led to the development of a simple and rapid method for the extraction and purification of lipids from biological materials. The entire procedure can be carried out in approximately 10 minutes; it is efficient, reproducible, and free from deleterious manipulations. The wet tissue is homogenized with a mixture of chloroform and methanol in such proportions that a miscible system is formed with the water in the tissue. Dilution with chloroform and water separates the homogenate into two layers, the chloroform layer containing all the lipids and the methanolic layer containing all the non-lipids. A purified lipid extract is obtained merely by isolating the chloroform layer. The method has been applied to fish muscle and may easily be adapted to use with other tissues.
This study, conducted between 1998 and 2001 and analyzed in 2002 and 2003, was designed to test (1) whether exercise is an efficacious treatment for mild to moderate major depressive disorder (MDD), and (2) the dose-response relation of exercise and reduction in depressive symptoms.
The study was a randomized 2x2 factorial design, plus placebo control.
All exercise was performed in a supervised laboratory setting with adults (n =80) aged 20 to 45 years diagnosed with mild to moderate MDD.
Participants were randomized to one of four aerobic exercise treatment groups that varied total energy expenditure (7.0 kcal/kg/week or 17.5 kcal/kg/week) and frequency (3 days/week or 5 days/week) or to exercise placebo control (3 days/week flexibility exercise). The 17.5-kcal/kg/week dose is consistent with public health recommendations for physical activity and was termed "public health dose" (PHD). The 7.0-kcal/kg/week dose was termed "low dose" (LD).
The primary outcome was the score on the 17-item Hamilton Rating Scale for Depression (HRSD(17)).
The main effect of energy expenditure in reducing HRSD(17) scores at 12 weeks was significant. Adjusted mean HRSD(17) scores at 12 weeks were reduced 47% from baseline for PHD, compared with 30% for LD and 29% for control. There was no main effect of exercise frequency at 12 weeks.
Aerobic exercise at a dose consistent with public health recommendations is an effective treatment for MDD of mild to moderate severity. A lower dose is comparable to placebo effect.
To estimate the effect of weight-loss interventions on health-related quality of life (HrQoL) in randomized controlled trials (RCTs); to conduct a meta-analysis of weight-loss treatment on depressive symptoms; and, to examine methodological and presentation issues that compromise study validity.
We conducted a structured review of 34 RCTs with weight-loss interventions that reported the relationship between HrQoL and treatment at two or more time points. We also evaluated study quality.
Trials lasted 6 weeks to 208 weeks and evaluated behavioral, surgical, or pharmacologic interventions. Nine of 34 trials showed HrQoL improvements in generic measures. Obesity-specific measures were more likely to show improvement in response to treatment than non-obesity-specific measures. Meta-analysis showed no treatment effect on depressive symptoms. Most trials tracked loss to follow-up and conducted intent-to-treat analysis, but only four trials concealed recruitment staff to randomization and 14 blinded the investigation team to randomization.
HrQoL outcomes, including depression, were not consistently improved in RCTs of weight loss. The overall quality of these clinical trials was poor. Better-designed RCTs using standardized HrQoL measures are needed to determine the extent to which weight loss improves HrQoL.
Diets and Omega-3 polyunsaturated fatty acids have been considered as important factors to reduce the risk of cardiovascular and inflammatory diseases, but there are few details on the effects on healthy subjects. The aim of the present study was to examine the variation of several physiological parameters in healthy subjects on different diets supplemented with Omega-3 fatty acids.
The experiment was carried out on 33 subjects divided into four groups according to a double-blind cross-over design with a 1 : 1 ratio for Omega-3 (vs. placebo) and open-label parallel-groups with a 1 : 1 ratio for the Zone diet (vs. the diet suggested by the Italian National Research Institute for Nutrition and Foods). Blood samples were collected at the beginning of the experiment and after 35 (cross-over) and 70 days. The Profile of Mood States test (POMS) was also performed.
The arachidonic acid/eicosapentaenoic acid ratio (AA/EPA) was strongly reduced by Omega-3 with a supplementary effect of the diet and in particular the Zone diet. The AA/EPA reduction was correlated with a concomitant decrease of insulin and homocysteine levels. The Zone diet reduced skinfold thickness and body fat percentage and also showed antioxidant effects. The mood state changed after Omega-3 supplementation, with an increased POMS index. This was related to a concomitant reduction of AA/EPA and was particularly evident in the Zone diet.
AA/EPA and mood state are differently influenced by diet and Omega-3, body fat is particularly reduced by Zone diet, while blood parameters such as triglycerides/HDL ratio, insulin and homocysteine are related to AA/EPA variations. These findings are discussed in terms of differences in the composition of the diets and the influences of Omega-3 on physiological functions.
There was insufficient evidence to support the use of oral fish oil (on its own or in the presence of other treatments) for the management of the weight loss syndrome often seen in patients with advanced cancer. Many people with advanced cancer develop a distressing weight loss syndrome. To date, treatment of associated symptoms has proved difficult. More recently, novel approaches have included the use of oral fish oils that can contain the omega-3 fatty acid eicosapentaenoic acid (or EPA) to stabilise weight loss and promote weight gain. This review of trials found that in weight losing persons with advanced pancreatic cancer, an EPA nutritional supplement was no better than a non EPA nutritional supplement. However, there was insufficient evidence to draw conclusions about its use in patients who have cancer of other tumour types.
Regular exercise and consuming long-chain n-3 fatty acids (FAs) from fish or fish oil can independently improve cardiovascular and metabolic health, but combining these lifestyle modifications may be more effective than either treatment alone.
We examined the individual and combined effects of n-3 FA supplements and regular exercise on body composition and cardiovascular health.
Overweight volunteers [body mass index (BMI; in kg/m(2)): >25] with high blood pressure, cholesterol, or triacylglycerols were randomly assigned to one of the following interventions: fish oil (FO), FO and exercise (FOX), sunflower oil (SO; control), or SO and exercise (SOX). Subjects consumed 6 g tuna FO/d ( approximately 1.9 g n-3 FA) or 6 g SO/d. The exercise groups walked 3 d/wk for 45 min at 75% age-predicted maximal heart rate. Plasma lipids, blood pressure, and arterial function were assessed at 0, 6, and 12 wk. Body composition was assessed by dual-energy X-ray absorptiometry at 0 and 12 wk only.
FO supplementation lowered triacylglycerols, increased HDL cholesterol, and improved endothelium-dependent arterial vasodilation (P<0.05). Exercise improved arterial compliance (P<0.05). Both fish oil and exercise independently reduced body fat (P<0.05).
FO supplements and regular exercise both reduce body fat and improve cardiovascular and metabolic health. Increasing intake of n-3 FAs could be a useful adjunct to exercise programs aimed at improving body composition and decreasing cardiovascular disease risk.
Correlates of adults’ participation in physical activity: review and update
- Trost