Figure 1 - uploaded by Hamidreza Raeisi-Dehkordi
Content may be subject to copyright.
Source publication
Context
The results of human clinical trials investigating the effects of flaxseed on glucose control and insulin sensitivity are inconsistent.
Objective
The present study aimed to systematically review and analyze randomized controlled trials assessing the effects of flaxseed consumption on glycemic control.
Data Sources
PubMed, Medline via Ovi...
Contexts in source publication
Context 1
... study selection process is shown in Figure 1. A total of 2592 reports were initially identified; after removing duplicates (n ¼ 1259), 1333 articles remained. ...
Context 2
... effect sizes for the influence of flaxseed on insulin, HbA1c, HOMA-IR, and QUIKI were robust in the leave-one-out sensitivity analysis, suggesting the omission of each single trial did not have a significant effect on the results of meta-analysis, but the effect of flaxseed on blood glucose was sensitive to the study performed by Rhee et al. 50 Removing this study from the analysis rendered the effect of flaxseed on blood glucose nonsignificant (WMD, À1.35 mg/dL; 95%CI, À3.01 to 0.31; P ¼ 0.11) (see Figure S1 in the Supporting Information online). ...
Similar publications
Introduction: Many experimental and clinical trials have suggested that flax-seed might be a potent antihypertensive, but the evidence concerning the effects of flaxseed supplements on plasma C-reactive protein (CRP) concentrations has not been fully conclusive. We assessed the impact of the effects of flaxseed supplementation on plasma CRP concent...
Citations
... Instead, these diets tend to lead to a little decrease in all these measurements. In general, the consumption of nuts and seeds has been shown to have beneficial effects in enhancing fasting blood glucose levels, glycemic regulation, and sensitivity to insulin [95][96][97][98]. Moreover, research has shown that nuts have a beneficial effect on satiety and appetite reduction, potentially explaining why studies have not shown a connection between nuts and obesity [99,100]. ...
Nuts possess a high concentration of essential nutrients and serve as a very effective source of bioactive chemicals that promote health. Therefore, they function as significant and nutritious snacks, while also being incorporated into numerous conventional and contemporary culinary preparations over the globe. It is strongly advised to regularly consume nuts in order to fully capitalize on the nutritional, bioactive, and antioxidant properties they possess, as well as to experience their desired taste and flavor. Robust scientific data indicate that individuals who consistently consume significant quantities of nuts (15 to 30 g of nuts) exhibit reduced prevalence of chronic non-communicable diseases. Nuts have been found to have positive health impacts, such as the potential to manage obesity and decrease the occurrence of cardiovascular disease (CVD), type 2 diabetes, several types of cancer, and other chronic diseases associated with food. The most robust and persistent positive impact of nut consumption is its correlation with decreased incidence of cardiovascular disease (CVD). Nuts find application in several food products within the food industry, encompassing oil, spreads, as well as in other sectors such as cosmetics and medicine, and as a viable source of biodiesel. The objective of this chapter is to provide a comprehensive overview of the characteristics, advantages, and uses of nuts.
... Some herbs and medicinal plants are frequently used for disease treatment or prevention. 14 According to some reports, herbs can help to NAFLD. 11 Curcumin is a yellow pigment derived from Curcuma longa L. (turmeric), that has been proposed to be effective in treating NAFLD. ...
Objectives: Curcumin has antioxidant properties and has been proposed as a potential treatment for NAFLD. The
aim of current systematic review and meta-analysis was to evaluate previous findings for the effect of curcumin
supplementation on glycaemic indices, lipid profile, blood pressure, inflammatory markers, and anthropometric
measurements of NAFLD patients.
Methods: Relevant studies published up to January 2024 were searched systematically using the following databases: PubMed, SCOPUS, WOS, Science Direct, Ovid and Cochrane. The systematic review and meta-analysis
were conducted according to the 2020 PRISMA guidelines. The quality of the papers was assessed the using
the Joanna Briggs Institute (JBI) Critical Appraisal Checklist. Pooled effect sizes were calculated using a random effects model and reported as the WMD and 95% CI. Also, subgroup analyses were done to find probable sources
of heterogeneity among studies.
Results: Out of 21010 records initially identified, 21 eligible RCTs were selected for inclusion in a meta-analysis.
Overall, 1191 participants of both genders, 600 in the intervention and 591 in the control group with NAFLD
were included. There are several limitations in the studies that were included, for instance, the results are
weakened substantially by potential bias or failure to account for potential adulteration (with pharmaceuticals)
or contamination (with other herbs) of the curcumin supplements that were tested. However, previous studies
have reported curcumin to be a safe complementary therapy for several conditions. Our study indicated that
curcumin supplementation in doses of 50− 3000 mg/day was associated with significant change in FBG [WMD: − 2.83; 95% CI: − 4.61, − 1.06), I2 = 51.3%], HOMA-IR [WMD: −0.52; 95% CI: − 0.84, − 0.20), I2= 82.8%], TG [WMD: − 10.31; 95% CI: − 20.00, − 0.61), I
2 = 84.5%], TC [WMD: − 11.81; 95% CI: − 19.65, − 3.96), I
2
= 94.6%], LDL [WMD: − 8.01; 95% CI: − 15.79, − 0.24), I
2 = 96.1%], weight [WMD: − 0.81; 95% CI: − 1.28,
− 0.35), I
2= 0.0%] and BMI [WMD: − 0.35; 95% CI: − 0.57, − 0.13), I
2= 0.0%] in adults with NAFLD. There was
no significant change in HbA1C, plasma insulin, QUICKI, HDL, SBP, DBP, CRP, TNF-α and WC after curcumin
therapy. Subgroup analysis suggested a significant changes in serum FBG, TG, SBP, WC in RCTs for intervention
durations of ≥ 8 weeks, and SBP, TG, LDL, HDL, BMI, WC in RCTs with sample size > 55 participants.
Conclusion: Curcumin supplementation in doses of 50− 3000 mg/day over 8–12 weeks was associated with significant reductions in levels of FBG, HOMA-IR, TG, TC, LDL, weight and BMI in patients with NAFLD. Previous
studies have reported curcumin as a safe complementary therapy for several diseases. We would suggest that
should curcumin supplements be used clinically in specific conditions, it should be used with caution. Also,
difference in grades of NAFLD may effect the evaluated outcomes, so it is suggested that future studies be
conducted with an analyses on subgroups according to their NAFLD grade. Furthermore, because of the failure to
conduct independent biochemical assessment of the turmeric/curcumin product used in most studies as well as
potential sources of bias, results should be interpreted with caution.
... The relationship between NUTSDS consumption and decreased mortality among MAFLD patients can be understood through multiple underlying mechanisms.NUTSDS is replete with bene cial compounds, including unsaturated fatty acids, protein, ber, vitamin E, potassium, magnesium, and a plethora of phytochemicals. A series of interventional studies have elucidated the capacity of NUTSDS to modulate lipid pro les, notably by diminishing total and LDL cholesterol levels while concurrently augmenting HDL cholesterol in a dose-correlated manner [32][33][34].Beyond lipid regulation, compelling evidence points towards NUTSDS's role in enhancing metabolic parameters, including optimizing fasting glucose levels, bolstering glycemic regulation, and augmenting insulin sensitivity [35][36][37][38][39].Delving deeper into vascular health, NUTSDS has been implicated in the attenuation of endothelial dysfunction [40,41], a reduction in lipid peroxidation [40], and the mitigation of insulin resistance [42]. Such effects could potentially decrease cardiovascular-associated mortalities in those with MAFLD. ...
Background
Recently, the designation "Metabolic Associated Fatty Liver Disease" (MAFLD) has emerged to more holistically depict the disease's multifaceted nature. Within this framework, patients are stratified as either metabolically healthy (MH) or metabolically unhealthy (MU). The unique nutrient composition of nuts and seeds (NUTSDS) suggests potential health advantages, potentially mitigating premature mortality risks.This research delves into the impact of NUTSDS consumption on all-cause mortality within the diverse MAFLD categories.
Methods
We embarked on a prospective cohort investigation involving 13,762 participants, drawn from a nationally representative pool of the National Health and Nutrition Examination Survey. Mortality events and underlying causes were tracked through a linkage with death records until December 31, 2019. To elucidate the connection between NUTSDS intake and mortality across MAFLD categories, we employed both the Weighted Cox proportional hazards regression and Restricted Cubic Spline (RCS) analytical methods.The robustness of our results is further buttressed by a series of stratified and sensitivity assessments.
Results
Out of the 13,762 studied participants, representing a weighted national estimate of 58,212,532individuals, 62.73% were MAFLD-diagnosed. Among them, 7.79% were MH-MAFLD, and 54.95% were MU-MAFLD. Over 135,552.9 person-years (median follow-up of 9.58 years), there were 1,558 recorded deaths. The fully adjusted Cox model demonstrated a 15% reduced risk of all-cause mortality with NUTSDS intake (HR, 0.85; 95%CI, 0.74–0.97) in the MAFLD group and a similar risk reduction in the MU-MAFLD group (HR, 0.86; 95%CI, 0.76–0.98). Notably, no such associations were found in the Non-MAFLD and MH-MAFLD groups. RCS analyses suggested a U-shaped mortality curve with optimal NUTSDS consumption levels at 3.79 oz/day for MAFLD and 3.87 oz/day for MU-MAFLD.
Conclusions
These insights accentuate the prospective protective effects of NUTSDS consumption against all-cause mortality in MAFLD individuals, especially salient in the MU-MAFLD demographic.
... Flaxseed oil has different effects, including anti-inflammatory (Oomah, 2001), anti-chemotactic (Monk et al., 2016), antioxidant (Barthet, Klensporf-Pawlik, & Przybylski, 2014), anti-atherosclerotic (Zanwar, Hegde, & Bodhankar, 2014), and anti-microbial (Mohammed & Hameed, 2018). In addition, flaxseed supplementation produces various potentially protective effects against chronic diseases, such as obesity (Mohammadi-Sartang et al., 2017), dyslipidemia , diabetes (Mohammadi-Sartang, Sohrabi, Barati-Boldaji, Raeisi-Dehkordi, & Mazloom, 2018), and metabolic syndrome (Tamtaji et al., 2020). Some trials claimed flaxseed could improve BP in adults (Dodin et al., 2005; Rodriguez-Leyva et al., 2013), whereas others did not (Billinsky et al., 2013;Dewell, Marvasti, Harris, Tsao, & Gardner, 2011). ...
We systematically reviewed randomized clinical trials (RCTs) to elucidate the overall effects of flaxseed oil consumption on blood pressure (BP) in patients with metabolic syndrome and related disorders. PubMed, Scopus, Cochrane Library, and ISI Web of Science databases were systematically searched until March 31, 2020, to find RCTs that examined the effect of flaxseed oil consumption on BP. Weighed mean difference (WMD) was pooled using a random-effects model. Standard methods were used for the assessment of heterogeneity, sensitivity analysis, and publication bias. Meta-analysis of five trials (6 arms) showed significant reductions in systolic (WMD: À3.86 mmHg, 95% CI: À7.59 to À0.13, p = .04) BP (SBP) after flaxseed oil consumption. However, the overall effect illustrated no significant change in diastolic (WMD:
... The intake of flaxseed can also repair damage in the lipidic and glycemic profile, as it is a functional food with a high PUFA content [83]. PUFAs can contribute to reducing specific inflammatory markers and cytokines, ensuring a general improvement of the endothelial function and, consequent, cardioprotective [84,85] and anti-hyperglycemic effects [86][87][88]. ...
... Another mechanism involved in the normalization of the glycemic profile is related to the fact that lignan suppresses the gene expression of phosphoenolpyruvate carboxykinase (PEPCK), which is related to the production of glucose, through gluconeogenesis, helping in glycemic control. The effects of regularization of the glycemic profile have also been attributed to PUFAs found in brown flaxseed [88]. ...
... The functional effects of M. oleifera extend to the strategies for the nutritional management of DM2, taking advantage of its anti-hyperglycemic properties [116,117] as well as its antioxidant potential [118,119]. Therefore, M. oleifera is widely used in human and animal studies, whose primary scope is to determine the anti-hyperglycemic effects of the plant and at the same time its antioxidant property through evaluation of the activity of enzymes, such as SOD (superoxide dismutase), CAT (catalase) and GSH (glutathione peroxidase) [48,88,116,117,120] The anti-hyperglycemic effect of M. oleifera can be attributed to its capacity to enhance the action of insulin [50,117]. This is because the plant has considerable quantities of bioactive phytochemicals (quercetin, kaempferol, chlorogenic acid and alkaloids), which act in synergy, increasing the secretion of insulin and leading to a better use of glucose by the tissues through blockage of hepatic gluconeogenesis [50]. ...
Functional clinical nutrition is an integrative science; it uses dietary strategies, functional foods and medicinal plants, as well as combinations thereof. Both functional foods and medicinal plants, whether associated or not, form nutraceuticals, which can bring benefits to health, in addition to being included in the prevention and treatment of diseases. Some functional food effects from Avena sativa L (oats), Linum usitatissimum L. (brown flaxseed), Glycine max L. (soya) and Moringa oleifera have been proposed for nutritional disorders through in vitro and in vivo tests. A formulation called a bioactive food compound (BFC) showed efficiency in the association of oats, flaxseed and soy for dyslipidemia and obesity. In this review, we discuss the effects of BFCs in other nutritional disorders, as well as the beneficial effects of M. oleifera in obesity, cardiovascular disease, diabetes mellitus type 2, metabolic syndrome, intestinal inflammatory diseases/colorectal carcinogenesis and malnutrition. In addition, we hypothesized that a BFC enriched with M. oleifera could present a synergistic effect and play a potential benefit in nutritional disorders. The traditional consumption of M. oleifera preparations can allow associations with other formulations, such as BFCs. These nutraceutical formulations can be easily accepted and can be used in sweet preparations (fruit and/or vegetable juices, fruit and/or vegetable vitamins, porridges, yogurt, cream, mousses or fruit salads, cakes and cookies) or savory (vegetable purees, soups, broths and various sauces), cooked or not. These formulations can be low-cost and easy-to-use. The association of bioactive food substances in dietary formulations can facilitate adherence to consumption and, thus, contribute to the planning of future nutritional interventions for the prevention and adjuvant treatment of the clinical conditions presented in this study. This can be extended to the general population. However, an investigation through clinical studies is needed to prove applicability in humans.
... Previous studies have demonstrated that flaxseed can be effective at lowering and stabilising the blood glucose response in healthy, pre-diabetic and diabetic individuals [11][12][13][14][15]. The question remains as to whether flaxseed is more effective at maintaining blood glucose at the normal level over 24 h when the portion is given once or spread out throughout the day. ...
... Flaxseed contains n-3 fatty acids alpha-linolenic acid has which has previously been shown to have a positive impact upon glycaemic control [37,38]. A previous systematic review and meta-analysis [14] showed that there was a significant association between flaxseed supplementation and a reduction in blood glucose; however, when subgroup analysis was completed the significant reduction in blood glucose were found only in studies using whole flaxseed but not flaxseed oil and lignan extract. However, the flaxseed oil was approaching significance (p = 0.08). ...
... However, the flaxseed oil was approaching significance (p = 0.08). Although the systematic review by Mohammadi-Sartang et al. [14] highlighted that flaxseed lignan extract had no significant impact on blood glucose, plant lignan has been suggested to be able to lower the risk of cardiovascular diseases as well as inhibit the effect of developing type two diabetes by reducing inflammatory response and insulin resistance [39]. It has been shown that flaxseed lignan secoisolariciresinol diglucoside restricts expression of the phosphoenolpyruvate carboxykinase gene, which is considered the main enzyme in glucose synthesis in the liver [40,41]. ...
PurposeFlaxseed can be effective at lowering and stabilising blood glucose responses. The aim of this study was to determine whether flaxseed could lower blood glucose response more effectively when consumed as a single portion of 30 g, or a split portion consumed three times per day (10 g flaxseed per portion).
Methods
The study was a randomised, repeated measures, cross-over design. Fifteen healthy participants consumed either (1) three flaxseed muffins containing a total of 30 g of flaxseed once in the morning, (2) three flaxseed muffins consumed at three different timepoints across the day (10 g flaxseed per muffin) or (3) three control muffins consumed at three different timepoints across the day (0 g flaxseed). The 24-h blood glucose response was measured using a continuous glucose monitor.
ResultsThe results of this study demonstrated that flaxseed muffins given three times a day were effective at lowering and maintaining blood glucose levels over 24 h, compared to the control muffins and that both flaxseed treatments resulting in a lower blood glucose iAUC during the night.Conclusion
The results of this study indicated that adding flaxseed to a daily diet produced a lower glucose profile over 24 h in a free-living context compared to the control muffins.
... Another systematic review and meta-analysis of flaxseed consumption for glycemic control concluded that whole flaxseed consumption improved glycemic control (Mohammadi-Sartang et al., 2018). This effort identified 25 RCTs with a WMD for blood glucose of −2.94 mg/dL (95% CI: −5.31 to −0.56; P = 0.015). ...
Seeds play important roles in human nutrition and health since ancient time. The term “specialty” has recently been applied to seeds to describe high‐value and/or uncommon food products. Since then, numerous studies have been conducted to identify various classes of bioactive compounds, including polyphenols in specialty seeds. This review discusses nutrients, fat‐soluble bioactives, polyphenols/bioactives, antioxidant activity, bioavailability, health benefits, and safety/toxicology of commonly consumed eight specialty seeds, namely, black cumin, chia, hemp, flax, perilla, pumpkin, quinoa, and sesame. Scientific results from the existing literature published over the last decade have been compiled and discussed. These specialty seeds, having numerous fat‐soluble bioactives and polyphenols, together with their corresponding antioxidant activities, have increasingly been consumed. Hence, these specialty seeds can be considered as a valuable source of dietary supplements and functional foods due to their health‐promoting bioactive components, polyphenols, and corresponding antioxidant activities. The phytochemicals from these specialty seeds demonstrate bioavailability in humans with promising health benefits. Additional long‐term and well‐design human intervention trials are required to ascertain the health‐promoting properties of these specialty seeds.
... The health-promoting effects of flaxseed have been described in many studies related to gastrointestinal diseases (Strojný et al., 2014;Laurino et al., 2017), including functions in hepatoprotection (-Andrejčáková et al. 2016) and hypocholesterolaemic benefits (Sopková et al., 2017). Other positive effects of flaxseed include assistance in the prevention of diabetes (Mohammadi-Sartang et al., 2018), cancer (Calado et al., 2018), and cardiovascular diseases (Bomba et al., 2012;Prasad and Jadhav, 2016). Flaxseed is a rich plant source of n-3 polyunsaturated fatty acids (PUFA), mainly essential a-linolenic acid (ALA). ...
... Dietary flaxseed improved body condition score in pigs receiving 5, 10, or 15% concentration (Juárez et al., 2010), piglets (Andrejčáková et al., 2016;Sopková et al., 2017;Vlčková et al., 2018) and mice with gut infections receiving 10% flaxseed in the diet. On the other hand, high portion of flaxseed in the diet fed for a long time period (more then 6 weeks) could cause lose weight in mice Pourjafari et al., 2019) and humans (Mohammadi-Sartang et al., 2018) or had no effect on body condition score (Rodriguez-Leyva et al., 2013). ...
Xylene is a common pollutant in the environment that enters the body of animals and humans in various ways, but most often through the respiratory tract and adversely affects their overall health. However, xylene effects after oral exposure have not been sufficiently studied. This study aimed to investigate the effects of xylene exposure on the mouse organism and to identify possible beneficial effects of flaxseed on such exposure. Eighty mice were divided into four groups: control group C (basal diet + no xylene exposure), group X (oral exposure by 400 mg/kg/day xylene), group F (10% flaxseed supplementation of basal diet), and group XF (10% dietary flaxseed + oral exposure by xylene). Experimental trial took 14 days. Clinical examination, spectroscopic analysis of tissue aminotransferases, total lactate dehydrogenase (TLDH), and acetylcholinesterase (AchE) activities, electrophoretic analysis of LDH isoenzymes, western blot and immunohistochemical analysis of apoptosis as well as routine histology of the kidneys and jejunum, and transmission electron microscopy of the liver were performed. Marked restlessness in group X and high weight losses in mice of all groups were recorded during the experiment. Xylene promoted apoptosis (caspase-3 expression) without causing marked structural changes in the liver and jejunum, although renal cortex structure was affected adversely. In the brain, liver, and kidney of mice, xylene increased levels of liver transaminases, LDH, and decreased AchE activities, reflecting cell membrane damage. Flaxseed feeding improved animal behaviour, leakage of enzymes and prevented selected tissue toxic damage induced by xylene by protecting cell membrane integrity and fluidity and by suppressing apoptosis. These results point at the protective effect of flaxseed consumption on mice.
... This was also confirmed in another study in which flaxseed consumption in patients with metabolic syndrome could result in blood glucose control and insulin resistance decline after 12 weeks [20]. Also, a recently published meta-analysis in this area also indicated this, but with this difference that only whole flaxseed, but not flaxseed oil and lignan extract, has significant effects on controlling glycemic parameters [49]. A possible explanation for the necessity of long-term intervention (≥ 12 weeks) is that improving glucose control and insulin sensitivity require an increase in EPA and Docosahexaenoic acid (DHA) concentrations [50,51] and ALA conversion to these two fatty acids is time-consuming [52]. ...
... Also, the function of the gut microflora is enhanced gradually by flaxseed fiber consumption, which in turn led to improved blood glucose control and insulin function [53,54]. As well, the higher initial concentration of plasma glucose (> 100 mg/dL), the more pronounced changes can be achieved via the flaxseed supplement [49]. ...
Regarding the increasing prevalence of cardiometabolic abnormalities, and its association with non-communicable chronic diseases, providing preventive and therapeutic strategies is a priority. A randomized placebo-controlled study was conducted to assess the effects of combination therapy of milled brown flaxseed and hesperidin during lifestyle intervention on controlling cardiovascular risk in prediabetes. A total of forty-eight subjects were randomly assigned to receive lifestyle intervention plus combination therapy of brown flaxseed (30 g milled) and hesperidin (two 500 mg capsules) or lifestyle modification alone for 12 weeks. Changes from baseline in anthropometric measures, lipid profile and atherogenic indices, glucose homeostasis parameters, and inflammatory biomarkers was assessed as a primary end point. Anthropometric data comparison between the two groups showed a significant reduction in weight (p = 0.048). Waist circumference reduction was about twice that of the control group (− 6.75 cm vs − 3.57 cm), but this difference was not statistically significant. Comparison of blood pressure changes throughout the study indicated a greater reduction in blood pressure in the intervention group rather than control group (− 5.66 vs. − 1.56 mmHg, P = 0.049). Improvements of lipid profile and atherogenic indices, glucose homeostasis parameters, and inflammatory biomarkers in flaxseed-hesperidin group was significantly more than the control group after 12 weeks of intervention (p < 0.05). Our results indicate that co-administration of flaxseed and hesperidin as an adjunct to lifestyle modification program is more effective than lifestyle modification alone in the metabolic abnormalities remission of prediabetic patients. Trial registration: The trial was registered with ClinicalTrials.gov, number NCT03737422. Registered 11 November 2018. Retrospectively registered, https://clinicaltrials.gov/ct2/results?cond=&term=NCT03737422&cntry=&state=&city=&dist=.
... Another plant source of v-3 fatty acid is flaxseed. However, Mohammadi-Sartang et al., in their systematic review and metaanalysis, concluded that whole flaxseed, but not flaxseed oil, has significant effects on improving glycemic control [33]. ...
Objective:
Chia seed oil is the richest source of plant-based ω-3 fatty acid, α-linolenic acid, but its potential and mechanisms of action to treat obesity are unclear. The aim of the study was to evaluate the effects of chia oil (ChOi) supplementation on body composition and insulin signaling in skeletal muscles of obese mice.
Methods:
Male C57 BL/6 mice (n = 8/group) were fed regular control chow or a high-fat diet (HFD) for 135 d. Another HFD group additionally received ChOi from 90 to 135 d.
Results:
Consumption of ChOi reduced fat mass accumulation and increased lean mass as evidenced by nuclear magnetic resonance. Moreover, obese mice treated with ChOi showed higher tyrosine phosphorylation of insulin receptor substrate 1, greater activation of protein kinase B, and increased translocation of glucose transporter type 4 in skeletal muscle tissue in response to insulin. ChOi supplementation improved glucose levels and insulin tolerance; decreased serum insulin, leptin, and triacylglycerols; and increased blood high-density lipoprotein cholesterol levels. All these effects caused by the use of ChOi seemed to be independent of the resolution of inflammation because the markers of inflammation were not altered in animals fed the HFD.
Conclusion:
The molecular effects observed in muscle tissue together with changes in body composition may have contributed to the increased glucose tolerance and to the healthy phenotype presented by obese animals treated with ChOi.