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n-3 Fatty Acids in the Brain and Retina: Evidence for Their Essentiality

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... The strong affinity of brain lipids for C22:6n-3 suggested a requirement for n-3 EFAs, but this requirement is difficult to study because n-3 EFAD develops only under extreme dietary conditions (125). An essential role for C22:6n-3 in brain and retinal PLs was described by Neuringer and Connor, who demonstrated C18:3n-3 deficiency in Rhesus monkeys fed during gestation diets with safflower oil (ratio of n-6 to n-3 of 255:1) as the sole source of fat (126). Their offspring reared on the same diet developed abnormal electroretinograms when compared with the control group, consisting of offspring fed soybean oil (ratio of n-6 to n-3 of 7). ...
... Learning capacity, as tested in a spatial reversal learning task, was not affected, possibly because of the observed compensatory increase of n-6 PUFAs, particularly C22:5n-6, in PL. Retinal n-3 PUFA deficiency was reversed at the ages of 10 and 24 months by feeding a fish oil diet rich in C20:5n-3 and C22:6n-3 (126). An EAR has not been set based on the correction of deficiency as a result of lack of data on the n-3 FA requirement in healthy subjects (115). ...
... Animal studies demonstrated impairment in the visual process, altered learning behavior, and low brain C22:6n-3 content resulting from a deficiency in C18:3n-3 and its metabolites C20:5n-3 and C22:6n-3 (125). Permanent learning defects and alterations in synaptic function in the brain, observed in EFAD during pregnancy, can be prevented by feeding n-3 EFAs (126). In addition, a correlation has been noted between diet-induced changes in C22:6n-3 in the retina and a modification of electrical potentials induced in rod outer segments by light stimulation. ...
... Although many experts believe that cholesterol-lowering diets are nutritionally adequate, concerns have been raised about their potentially harmful effects on an individual's psychological and physical well-being (Lifshitz & Moses, 1989;Mauer, 1985;Muldoon & Manuck, 1992;Muldoon, Manuck, & Matthews, 1990;Newman, Browner, & Hulley, 1990;Pugliese, Weyman-Daum, Moses, & Lifschitz, 1987). Essential fatty acids are important components of cerebral tissue (Neuringer, Anderson, & Connor, 1988;Neuringer & Connor, 1986). Although dietary studies with animals have yielded conflicting results (Caffrey & Patterson, 1971;Greenwood & Winocur, 1990), they have raised the possibility that diets low in essential fatty acids may adversely affect cognitive development and learning in humans (Bourre, Piciotti, Dumont, Pascal, & Durand, 1990). ...
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The Dietary Intervention Study in Children (DISC), a 2-arm, multicenter intervention study, examined the efficacy and safety of a diet lower in total fat, saturated fatty acids, and cholesterol than the typical American child's diet. A total of 663 8- to 10-year-old children with elevated low-density lipoprotein cholesterol levels were randomly assigned to either an intervention or a usual-care group. Intervention included group and individual counseling sessions to assist participants in adopting a dietary pattern containing 28% or less of calories from total fat (<8% as saturated fat, up to 9% as polyunsaturated fat, and 11% as monounsaturated fat) and dietary cholesterol intake of less than 75 mg/1,000 kcal. The dietary intervention reduced low-density lipoprotein cholesterol levels, and 3-year results showed no adverse effects for children in the intervention group in terms of academic functioning, psychological symptoms, or family functioning.
... Flax oil is rich in alpha-linolenic acid (ALA), an omega-3 fatty acid important for nervous system development, visual acuity [12], and for reducing incidences of diabetes, cancer, and other diseases in humans [13]. Fish-fed omega-3-fatty acid-rich flax seed showed an improved performance and fatty acid profile [14,15]. ...
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Winter cropping can be used to achieve a double benefit for producers: as soil cover and an additional economic crop cycle. Flax (Linum usitatissimum L.) is a spring crop growing in the northern region of the US and used as a fall cover crop in some southern states. In this study, eight seed-type flax varieties were evaluated for production as a fall/winter crop for the Commonwealth of Virginia, a mid-latitude region. Mixed results were obtained; however, the crop showed winter tolerance and potential productivity, especially when the frequency of sub-zero winter temperatures was low. Planting too early in the fall allows for significant stem development that increases susceptibility to physical damage by snowstorms and winter frost. Seed yield was low compared to spring-planted crops; however, it reached up to 400 kg ha−1 in some varieties. Seed weights were comparable to those found elsewhere for the same or other varieties, and seed protein and crude fat content ranged from 228–270 and 189–234 g kg−1, respectively. Across years and varieties, P, K, Mg, Ca, and S averaged 7.74, 9.88, 3.88, 2.86, and 2.35 g kg−1, respectively. Mineral elements Fe, Zn, Mn, Cu, and B averaged 95, 62, 21, and 10 mg kg−1, respectively. However, early maturity in spring ahead of other grains subjected it to significant losses to wild birds. Fall-planted flax has potential as a cover crop and may be harvested for seed, which in addition to a summer crop, provides a producer with economic returns from two crop cycles per year.
... The work presented herein aims to advance us a step further in that direction. The brain is the most lipid-rich organ and consumes about 20% of the body's total energy 16,17 . Thus, insults and injuries to the brain (e.g. ...
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Discovery of reliable signatures for the empirical diagnosis of neurological diseases—both infectious and non-infectious—remains unrealized. One of the primary challenges encountered in such studies is the lack of a comprehensive database representative of a signature background that exists in healthy individuals, and against which an aberrant event can be assessed. For neurological insults and injuries, it is important to understand the normal profile in the neuronal (cerebrospinal fluid) and systemic fluids (e.g., blood). Here, we present the first comparative multi-omic human database of signatures derived from a population of 30 individuals (15 males, 15 females, 23–74 years) of serum and cerebrospinal fluid. In addition to empirical signatures, we also assigned common pathways between serum and CSF. Together, our findings provide a cohort against which aberrant signature profiles in individuals with neurological injuries/disease can be assessed—providing a pathway for comprehensive diagnostics and therapeutics discovery.
... The brain is the most lipid-rich organ and consumes about 20% of the body's total energy. 16, 17 Thus, insults and injuries to the brain (e.g. TBI), and the associated disruption of blood supply can generate a metabolic crisis that, if unresolved, can increase brain atrophy and worsen outcomes. ...
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Discovery of reliable signatures for the empirical diagnosis of neurological diseases – both infectious and non-infectious – remains unrealized. One of the primary challenges encountered in such studies is the lack of a comprehensive database representative of a signature background that exists in healthy individuals, and against which an aberrant event can be assessed. For neurological insults and injuries, it is important to understand the normal profile in the neuronal (cerebrospinal fluid) and systemic fluids (e.g., blood). Here, we present a comparative multi-omic human database of of serum and cerebrospinal fluid signatures derived from a population of 30 individuals (15 males, 15 females, 23–74 years) as a first step towards establishing a comprehensive database in future. In addition to empirical signatures, we also assigned common pathways between serum and CSF. Together, our findings provide a strategy to establish a biomarker baseline against which aberrant signature profiles in individuals with neurological injuries/disease can be assessed – providing a pathway for comprehensive diagnostics and therapeutics discovery.
... 5 Many advantages have been reported among the various studies in the literature about the efficacy of breastfeeding on brain development, which is mainly attributable to the abundant presence of bioactive compounds , and the essential fatty acids in the breast milk, moreover, it has been proven that breastfeeding enhance the long-term outcomes in these children. [6][7][8][9] In this context, arachidonic acid and docosahexaenoic acid are two fatty acids that were previously reported to be associated with the developmental outcomes of the retina, nerve cells and brain. Both of these amino acids have also been found in breast milk and are not present in other milk formulas as cow's milk that are usually administered to newborns. ...
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Many advantages have been reported among the various studies in the literature about the efficacy of breastfeeding on brain development, which is mainly attributable to the abundant presence of the bioactive compounds and the essential fatty acids in breast milk. Moreover, it has been proven that breastfeeding enhanced long-term outcomes in children. In this context, arachidonic acid and docosahexaenoic acid are two fatty acids that were previously reported to be associated with the developmental outcomes of the retina, nerve cells and brain. Both of these amino acids have also been found in breast milk, and they are not present in other milk formulas as cow’s milk which is usually administered to newborns. In the present literature review, we aim to discuss the impact of exclusive breastfeeding on neurodevelopment. The findings from various studies indicate the strong effect of breastfeeding on the neurodevelopmental outcomes as compared to the administration of other milk formulas. Another finding from previous literature, the favorable events that are obtained from breastfeeding were also found to be sustained to the school-age of these children. On the other hand, evidence regarding the efficacy of breastfeeding on brain development in preterm infants is still poor. As a result, further studies are needed to furtherly validate this point. The main mechanisms by which favorable neurodevelopmental outcomes are obtained following breastfeeding are the nutritional values that are found within the breast milk along with the physical interactions between the mothers and infants during breastfeeding.
... Introduction Long-chain polyunsaturated fatty acids (LCPUFA), such as docosahexaenoic acid (DHA) and arachidonic acid (AA), are important structural components of the human brain that mainly accumulate during the third trimester of pregnancy and early infancy [1][2][3]. Human breast milk contains DHA, AA, and their fatty acid precursors [4] but, historically, infant formula contained only the precursors alpha linoleic acid and linoleic acid, which infants, especially those born preterm, may not be able to effectively synthesise into DHA and AA [5]. ...
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Lack of preformed long-chain polyunsaturated fatty acids (LCPUFA) in infant formula has been hypothesised as contributing to cognitive differences between breast-fed and formula-fed infants. Previous systematic reviews found no cognitive differences between infants fed formula with LCPUFA and those fed formula without, but focused on early developmental measures, such as Bayley Scales of Infant Development, which are poorly differentiating and not predictive of cognitive ability in childhood. This systematic review examined the effect of randomising infants to formula supplemented with LCUFA vs unsupplemented formula on cognitive function ≥ age 2.5 years. We searched Medline, Embase the Cochrane Central Register of Controlled Trials without date limit, following a pre-published protocol according to PRISMA guidelines. We conducted random effects meta-analyses in RevMan v5.4 and followed GRADE and Cochrane Guidelines to evaluate strength of evidence and potential for bias. We included 8 trial cohorts which randomised participants between 1993 and 2004 and analyse 6 previously unpublished outcomes provided by various trialists. Age at the last available cognitive test ranged from 3.3 to 16 years. The pooled mean difference in Wechsler Preschool and Primary Scale of Intelligence-Revised from four trials in term-born children showed no benefit of LCPUFA: -0.04 points (95% confidence interval -5.94 to 5.85, 95% prediction interval -14.17 to 14.25). The pooled mean difference in Wechsler Abbreviated Scale of Intelligence score from two trials in preterm-born children also showed no benefit of LCPUFA: -7.71 (95% CI -24.63 to 9.22, 95% PI -97.80 to 82.38). Overall quality of evidence was low, due to substantial heterogeneity, low rates of follow-up, and indications of selective publication. The long-term effect of LCPUFA supplementation in term and preterm-born infants on cognition is highly uncertain and includes potential for large benefit as well as large harm. Based on our findings, LCPUFA supplementation of infant formula is not recommended until further robust evidence excludes long-term harm. Study registration PROSPERO registration numbers CRD42018105196 and CRD42018088868.
... Thus it may be expected that the level of DHA in the retina is influenced by the n-3 fatty acid content of the diet. It has been shown however that whereas many organs and tissues are depleted of DHA during n-3 fatty acid dietary deficiency, the retinal DHA concentrations are conserved for a longer period (Neuringer and Conner, 1986). For instance it has been shown that the level o f DHA in the rods of albino rats fed on fatfree diets for 1 0 -1 2 weeks did not change whereas in other tissues it was depleted (Anderson et al., 1974). ...
Thesis
The purpose of this study was to investigate possible mechanisms for the retinal degeneration seen in adult Refsum disease. This is an inherited disorder in which phytanic acid, a dietary branched chain fatty acid, cannot be catabolised and as a result it accumulates in tissues and serum. Phytanic acid has the same structure as the side chain of the tocopherols (vitamin E), and some of the signs and symptoms seen in patients with severe and chronic vitamin E deficiency are similar to those seen in adult Refsum disease. For these reasons it has been suggested that an accumulation of phytanic acid in membranes may interfere with vitamin E function. Alternatively phytanic acid may exert its pathological effect through alteration of membrane composition and structure, thereby affecting membrane functions. These hypotheses were investigated by studying the effect of modulating phytanic acid and α-tocopherol concentrations on the lipid composition and certain functional parameters of retinal cell lines in culture. Methods were established and validated for (i) the supplementation of the cell lines with reproducible concentrations of phytanic acid and α-tocopherol, (ii) the quantification of various membrane components of interest, (iii) the measurement of membrane fluidity and the membrane transport of choline, and (iv) the determination of the susceptibility of altered membranes to in vitro lipid peroxidation. Results showed a) the phospholipid fraction of retinal cells readily incorporated phytanic acid resulting in an altered membrane fatty acid composition b) there was no competition in uptake between phytanic acid and α-tocopherol, c) the incorporation of phytanic acid increased membrane fluidity and the transport of choline, and d) the incorporation of phytanic acid did not appear to affect the susceptibility of membranes to in vitro lipid peroxidation. Taken together these results suggested that phytanic acid did not interfere with the incorporation and function of α-tocopherol in retinal membranes but directly affected retinal membrane composition, structure and function.
... Introduction Long-chain polyunsaturated fatty acids (LCPUFA), such as docosahexaenoic acid (DHA) and arachidonic acid (AA), are important structural components of the human brain that mainly accumulate during the third trimester of pregnancy and early infancy [1][2][3]. Human breast milk contains DHA, AA, and their fatty acid precursors [4] but, historically, infant formula contained only the precursors alpha linoleic acid and linoleic acid, which infants, especially those born preterm, may not be able to effectively synthesise into DHA and AA [5]. ...
Article
Full-text available
Lack of preformed long-chain polyunsaturated fatty acids (LCPUFA) in infant formula has been hypothesised as contributing to cognitive differences between breast-fed and formulafed infants. Previous systematic reviews found no cognitive differences between infants fed formula with LCPUFA and those fed formula without, but focused on early developmental measures, such as Bayley Scales of Infant Development, which are poorly differentiating and not predictive of cognitive ability in childhood. This systematic review examined the effect of randomising infants to formula supplemented with LCUFA vs unsupplemented formula on cognitive function � age 2.5 years. We searched Medline, Embase the Cochrane Central Register of Controlled Trials without date limit, following a pre-published protocol according to PRISMA guidelines. We conducted random effects meta-analyses in RevMan v5.4 and followed GRADE and Cochrane Guidelines to evaluate strength of evidence and potential for bias. We included 8 trial cohorts which randomised participants between 1993 and 2004 and analyse 6 previously unpublished outcomes provided by various trialists. Age at the last available cognitive test ranged from 3.3 to 16 years. The pooled mean difference in Wechsler Preschool and Primary Scale of Intelligence-Revised from four trials in termborn children showed no benefit of LCPUFA: -0.04 points (95% confidence interval -5.94 to 5.85, 95% prediction interval -14.17 to 14.25). The pooled mean difference in Wechsler Abbreviated Scale of Intelligence score from two trials in preterm-born children also showed no benefit of LCPUFA: -7.71 (95% CI -24.63 to 9.22, 95% PI -97.80 to 82.38). Overall quality of evidence was low, due to substantial heterogeneity, low rates of follow-up, and indications of selective publication. The long-term effect of LCPUFA supplementation in term and preterm- born infants on cognition is highly uncertain and includes potential for large benefit as well as large harm. Based on our findings, LCPUFA supplementation of infant formula is not recommended until further robust evidence excludes long-term harm.
... In particular, the polyunsatured fatty acids and antioxidants contained in breast milk have been directly related to the development of the retina and neural development. 10,11 Since formula feeding is frequently used in developed countries, formulas which are close to breast milk have been developed. For example, docosahexaneoic acid (DHA), which was present in lower amounts in the formulas than in breast milk, has been added to formula foods in recent years. ...
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Background/Objective: Performance of ocular examinations on children who were breastfed, fed with formula, and combination of the two for the first 6 months of age. Subsequently, refractive errors, allergic conjunctivitis, and retinal nerve fiber layer (RNFL) thickness were evaluated. Materials and Methods: The present study included a total of 242 eyes of 121 children (aged 60-84 months, 65 males, 56 females) admitted to the outpatient clinic of our institution. The patients were divided into three groups according to their feeding pattern during their first 6 months postdelivery: breastfed children (Group 1, n = 40), children fed with a combination of breast and formula milk (Group 2, n = 41), and children exclusively fed with formula-milk (Group 3, n = 40). All patients underwent detailed ophthalmologic examinations, and measurements of the RNFLs were recorded. Results: No significant difference was observed between the groups in terms of refractive error. In Group 3, we found that allergic conjunctivitis was significantly higher than in the other groups. In addition, in Group 3, the thickness of the RNFL was found to be significantly higher in the superior quadrants of both the eyes of children than in Groups 1 and 2 (p < 0.05). Conclusions: We found that the type of feeding experienced by infants in their first 6 months has no effect on refractive error but has significant effects on both allergic conjunctivitis and RNFL. To determine the cause of this difference in the RNFL and to further validate the present study, future studies with larger patient groups and animal experiments are needed.
... Thus, differences in nutrient composition between breast milk and infant formula may contribute to the relatively improved CNS developmental outcomes associated with breastfeeding. For example, one component of breast milk, the long-chain omega-3 fatty acid docosahexaenoic acid (DHA), is present at high levels in the brain and retina and accumulates rapidly in the infant brain, a process dependent on both endogenous synthesis and dietary supply (Neuringer and Connor, 1986). DHA is present in breast milk, and in recognition of its role in visual and cognitive development (Carlson and Neuringer, 1999) has been added to infant formulas since 2001. ...
... In addition, the n-3 series of alpha-linolenic acid (C18 : 3, n-3), which are particularly representative fatty acids of perilla oil, can be converted to eicosapentaenoic acid (EPA, C20 : 5, n-3) and docosahexaenoic acid (DHA, C22 : 6, n-3) by desaturation and chain elongation in human bodies [4,5]. ese n-3 series of fatty acids are essential to synthesize brain phospholipids and are known to improve brain function, including learning ability [6]. Vegetable fats also contain high levels of phytosterols and vitamin E, thus have antioxidant activity; these constituents confer oxidative stability for food processing, storage, and distribution [7,8]. ...
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This study was undertaken to evaluate chemical characteristics and oxidative stability of tree-borne seed oils. A total of 15 different fatty acids were identified in six tree-borne seed oils, which included seven types of saturated fatty acids, four types of monounsaturated fatty acids, and four types of polyunsaturated fatty acids. Japanese camphor tree (JCT) had a high content of medium-chain fatty acids (97.94 ± 0.04%), in which fatty acid composition was distinct from those of the other five plant seed oils. Overall, contents of tocopherols, a type of fat-soluble vitamin, ranged between 3.82 ± 0.04 mg/100 g and 101.98 ± 1.34 mg/100 g, respectively. Phytosterol contents ranged from 117.77 ± 1.32 mg/100 g to 479.45 ± 4.27 mg/100 g, respectively. Of all tree-borne seed oils, β -sitosterol was the phytosterol at the highest concentration. Contents of unsaponifiables were between 0.13 ± 0.08 and 2.01 ± 0.02, and values of acid, peroxide, and p -anisidine were between 0.79 ± 0.01 and 38.94 ± 0.24 mg KOH/g, 3.53 ± 0.21 and 127.67 ± 1.79 meq/kg, and 2.07 ± 0.51 and 9.67 ± 0.25, respectively. Oxidative stability of tree-borne seed oils was assessed through measurement of oxidation-induction periods. These results should serve as a foundation to identify the potential of tree-borne seed oils in industrial application as well as in providing fundamental data.
... This raises the question of whether an -3 PUFA deficient animal model produced over several generations is suitable for studies investigating the influence of LC-PUFA on behavior. The biosynthesis of DHA from ALA in rodents is more effective than in nonhuman primates [68], i.e. a longer period of -3 PUFA deprivation (more than one generation) is needed to achieve a reduced DHA concentration in the brain [37,67]. A recent study investigated the effects of -3 PUFA reduction over four generations in Wistar rats and failed to find any significant changes in attention and impulsivity [69]. ...
Article
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Polyunsaturated fatty acids (PUFAs), particularly the omega-3 PUFAs, are thought to be involved in neuronal processes, to play a role in neurodevelopmental disorders and to be important for the integrity of central nervous system functioning. The present study investigated the effects of nutritional omega-3 PUFAs on attentional functions and impulsive behavior in Wistar rats. For this purpose, female Wistar rats were fed an omega-3 deficient diet over several generations, and the dams of the seventh generation were randomly assigned to two diet groups and fed an omega-3 deficient or an omega-3 sufficient diet. In addition, a group of previously untreated dams was fed an omega-3 sufficient diet. The male offspring of these three diet groups were tested using an established paradigm for the assessment of attention and impulsive behavior, i.e. a modified version of the five-choice-serial-reaction-time task (5CSRTT). The present data show that the deficiency of omega-3 PUFAs over generations led to substantial changes in attentional processes and impulsive behaviors. The impairments associated with an omega-3 deficiency were partly corrected by treatment with the omega-3 sufficient diet in the last generation of the omega-3 deficient group which showed substantial improvements in attention parameters. While there were no significant effects of dietary modifications on psychomotor activity levels, there was some evidence for changes in impulsive behavior. In conclusion, transgenerational dietary changes in the availability of omega-3 PUFAs led to changes in attentional processes and impulsive behavior in rats, supporting the hypothesis that omega-3 PUFAs play a role in cognitive and behavioral processes. The present findings offer a promising approach in the investigation of the role of omega-3 PUFAs in a variety of cognitive and behavioral domains.
... In the early months postnatally, DHA increases substantially and constitutes between 25 and 60% of the phospholipid FA in these tissues (3,4). Earlier studies demonstrated that growing rats and monkeys fed a diet deficient in n-3 FA had behavioral changes, abnormal retinal responses to light, and poorer visual acuity development as compared with controls (3,5). These disturbances seem to be irreversible, since visual acuity did not reverse when the animals were fed long-chain n-3 PUFA [LCPUFA(n-3)] as adults, indicating an early critical period for the accumulation of DHA in neural tissues (6). ...
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The aim of this research was to investigate the effect of fish oil supplementation, in the third trimester of pregnancy and early lactation period of healthy pregnant Danish women. Forty-four pregnant women were randomly allocated to fish oil supplementation (1.3 g EPA and 0.9 g DHA per day) from week 30 of gestation (FO-group) or to a control regimen (olive oil or no oil; controls). The FO-group was randomly subdivided into women stopping fish oil supplementation at delivery [FO(pregn)], and women continuing supplementation for an additional 30 d [FO(pregn/lact)]. Thirty-six women agreed to collect milk samples at days 4, 16, and 30 postpartum. The FA composition of the milk samples was determined by GLC. At days 4, 16, and 30 in lactation, FO(pregn/lact) women (n = 12) had, respectively 2.3 (P = 0.001), 4.1 (P = 0.001), and 3.3 (P = 0.001) times higher mean contents of LCPUFA(n-3) in their breast milk compared with controls (n = 13), and 1.7 (P = 0.005), 2.8 (P = 0.001), and 2.8 (P = 0.001) times higher LCPUFA(n-3) contents, respectively, at these days compared with FO(pregn) women (n = 11). The latter group did not differ significantly from controls with regard to LCPUFA(n-3) content in the breast milk. Similar results were obtained when analyzing separately for effects on the milk content of DHA. Dietary supplementation with 2.7 g LCPUFA(n-3) per day from week 30 of gestation and onward more than tripled the LC-PUFA(n-3) content in early breast milk; supplementation limited to pregnancy only was much less effective.
... The possible imbalance of AA to EPA/DHA, either in the diet or through altered metabolism, has several implications for brain function, because (1) DHA ideally constitutes *33% of the fatty acids in the cerebral cortex (the dry weight of the brain being 60% phospholipids), optimizing membrane fluidity and receptor nesting sites (Chang et al. 2009;Bradbury 2011); and (2) EPA is also the precursor for the series 3 eicosanoids (prostaglandins, thromboxanes, and leukotrienes), which are anti-inflammatory and necessary for cell communication (Neuringer and Connor 1986;Singh 2005;Chang et al. 2009;Bradbury 2011). The O6 20-carbon four-unsaturatedbond AA is the precursor of the pro-inflammatory two series of eicosanoids (Harris et al. 2009;Lenihan-Geels et al. 2013). ...
Article
Objective: To examine fatty acid profiles, their response to omega-3 fatty acid (Ω3) supplementation, and associations with clinical status and treatment response in youth with mood disorders. Methods: In a placebo-controlled 2X2 design, 7-14 year-olds (N = 95) in parallel pilot trials (depression N = 72; bipolar N = 23) were randomly assigned to 12 weeks of Ω3 supplementation (1.4 g eicosapentaenoic acid [EPA], 0.2 g docosahexaenoic acid [DHA], and 0.27 g other Ω3 per day); psychoeducational psychotherapy (PEP); their combination; or placebo (mainly oleic and linoleic acid) alone. Blood was drawn at baseline (N = 90) and endpoint (n = 65). Fatty acid levels were expressed as percent of total plasma fatty acids. Correlational and moderator/mediator analyses were done with SPSS Statistics 23. Results: At baseline: (1) DHA correlated negatively with alpha-linolenic acid (ALA) (r = -0.23, p = 0.029); (2) Arachidonic acid (AA, Ω6) correlated negatively with global functioning (r = -0.24, p = 0.022); (3) Total Ω3 correlated negatively with age (r = -0.22, p = 0.036) and diastolic blood pressure (r = -0.31, p = 0.006). Moderation: Baseline ALA moderated response to Ω3 supplementation: ALA levels above the sample mean (lower DHA) predicted significantly better placebo-controlled response (p = 0.04). Supplementation effects: Compared to placebo, 2 g Ω3 per day increased EPA blood levels sevenfold and DHA levels by half (both p < 0.001). Body weight correlated inversely with increased EPA (r = -0.52, p = 0.004) and DHA (r = -0.54, p = 0.003) and positively with clinical mood response. Mediation: EPA increase baseline-to-endpoint mediated placebo-controlled global function and depression improvement: the greater the EPA increase, the less the placebo-controlled Ω3 improvement. Conclusion: Ω3 supplementation at 2 g/day increases blood levels substantially, more so in smaller children. A possible U-shaped response curve should be explored.
... Estudos pioneiros conduzidos por Neuringer (30) e Connor (31) , em 1986 e 1992 demonstraram ser necessária uma provisão adequada de ácido docosahexaenoíco em três períodos da vida: gestação, lactação e infância. ...
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Os lipídios são formados por diversos compostos químicos bastante diferentes entre si, sendo os ácidos graxos as substâncias presente em maior quantidade.A ingestão inadequada de ácidos graxos poliinsaturados têm sido relacionados com diversas doenças, tais como: doenças cardiovasculares; doenças autoimunes, alguns tipos de câncer e artrite reumatoíde. Para entender os efeitos dos lipídios no organismo animal é necessário conhecer a composição lipídica dos alimentos, bem como as etapas de absorção e digestão destes compostos. Os ácidos graxos, componentes lipídicos presentes em maior quantidade nos alimentos, estão esteriifcados como triacilglicerol e fosfolipídio. Estes compostos têm uma importância fisiológica para manutenção das estruturas, funções e integridade das membranas celulares, e isto faz com que o organismo animal tenha uma série de mecanismos para alterar o número de átomos de carbono e de duplas ligações de um ácido graxo, para que este seja adequado à necessidade da membrana celular. A razão entre o consumo de ácidos graxos w6 ew3 na dieta é um importante fator para determinar a ingestão adequada de lipídios, bem como prevenir o aparecimento de doenças. O objetivo desta revisão é descrever os mecanismos bioquímicos envolvidos na digestão, absorção e metabolismo dos lipídios, destacando a importância dos ácidos graxos ômega 3 na nutrição humana.
... It belongs to the genus Linum and family Linaceae. It has been a rich source of 2 essential fatty acids, alpha-linolenic acid (Lorgeril et al., 1999;Foulk et al., 2002) and linoleic acid (Bloedon and Szapary, 2004;Lorgeril et al., 1999), which on metabolism lead to the synthesis of DHA (docosa hexaeenoic acid), an indispensible metabolite for the optimal development of nervous system and maturation of visual acuity (retina) in infants (Neuringer and Connor, 1986;Uauy et al., 1996). Studies on early civilizations like Greeks and Egyptians reveal its use as food as well as laxative (Berglund, 2002). ...
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Four inter and eight intraspecific hybrids, obtained after crossing 6 cultivated and 2 wild species of Linum, were evaluated in detail for assessment of crossability and evaluation of various agro-morphological traits along with the screening for linseed rust resistance. In this study interspecific hybridization between Linum species with different chromosome numbers (L. grandiflorum) failed to produce hybrids whereas species with equal chromosome (L. angustifolium) numbers responded well. Analysis of variance revealed significant differences among entries for all the traits. The intraspecific hybrids (T-397 x HimAlsi-1) revealed higher seed yield over the interpsecific hybrids due to involvement of both elite cultivated parents. The interspecific hybrids were observed to superior for yield contributing traits i.e. T-397 x L. angustifolium for primary and secondary branches, HimAlsi-2 x L. angustifolium for capsules and biological yield per plant, Kangra Local x L. angustifolium for seeds per capsule and harvest index. The hybrids having wild species L. angustifolium as one of the parents appeared to be important for the improvement of the cultivated linseeds as T-397 x L. angustifolium recorded highest crossability. All hybrids were rust resistant highlighting the importance of wild species as a potential source of rust resistant genes for breeding programs.. © Society for the Advancement of Breeding Research in Asia and Oceania (SABRAO) 2016.
... Long chain PUFAs are predominant fatty acids of brain lipids, especially phos-pholipids, which are important in the nervous system. 42 Also, the activity of membrane-associated enzymes, neurotransmitters and cognitive function can be influenced by the changes in the fatty acid composition of the membranes. [43][44][45] Determination of the fatty acid composition of the brain revealed that it was also affected by dietary fat. ...
Article
Western life style, and high calorie diet in particular is causing major health problems such as insulin resistance, hepatic steatosis and heart disease in the modern age. High fat diet (HFD) induces similar changes in mice, such as increased body weight, hypercholesterolemia and accumulation of triglycerides in the liver. These changes can be ameliorated by the administration of some Lactobacillus species. The focus of this study was to analyze the fatty acid content of liver, heart and brain tissues of mice fed HFD and administered with either Lactobacillus plantarum WCFS1 or Lactobacillus rhamnosus LA68, and to analyze the fatty acid content of these organs after a two months washout period. The fatty acid composition of mouse liver tissue changed significantly due to probiotic administration during a 12 weeks HFD regime and active Lactobacillus administration had a slightly reversing effect toward the standard mouse diet group, but after the washout period these changes disappeared. The fatty acid composition of the heart and brain tissues was significantly changed in the HFD regime but probiotic administration had no significant influence on the fatty acid profile of these two organs. Upon the 8 weeks washout period the only remaining beneficial effect was the significantly lower mouse weight in the supplemented groups compared to the HFD group.
... 9 Because animals cannot synthesize n-3 PUFAs, humans depend on their diet for this nutrient. 10 Marine animals contain a relatively high concentration of n-3 PUFAs because aquatic plants synthesize these molecules. ...
Article
Although a rich source of n-3 polyunsaturated fatty acids (PUFAs) that may confer multiple health benefits, some fish also contain methyl mercury (MeHg), which may harm the developing fetus. U.S. government recommendations for women of childbearing age are to modify consumption of high-MeHg fish to reduce MeHg exposure, while recommendations encourage fish consumption among the general population because of the nutritional benefits. The Harvard. Center for Risk Analysis convened an expert panel (see acknowledgments) to quantify the net impact of resulting hypothetical changes in fish consumption across the population. This paper estimates the impact of prenatal n-3 intake on cognitive development. Other papers quantify the negative impact of prenatal exposure to MeHg on cognitive development, and the extent to which fish consumption protects against coronary heart disease mortality and stroke in adults. This paper aggregates eight randomized controlled trials (RCTs) comparing cognitive development in controls and in children who had received n-3 PUFA supplementation (seven studies of formula supplementation and one study of maternal dietary supplementation). Our analysis assigns study weights accounting for statistical precision, relevance of three endpoint domains (general intelligence, verbal ability, and motor skills) to prediction of IQ and age at evaluation. The study estimates that increasing maternal docosahexaenoic acid (DHA) intake by 100 mg/day increases child IQ by 0.13 points. The paper notes that findings were inconsistent across the RCTs evaluated (although our findings were relatively robust to changes in the weighting scheme used). Also, for seven of the eight studies reviewed, effects are extrapolated from formula supplementation to maternal dietary intake.
... Human fetuses and young infants have limited ability to synthesise n-3 LCPUFA de novo and are supplied via maternal (placental transfer, breast milk) or external (formula) sources. Deprivation of n-3 LCPUFA, both prenatally and after birth, has deleterious effects on learning abilities, memory and visual grating acuity in monkeys, infants and rats (41,42) . ...
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Neurodevelopment has been linked, among other factors, to maternal and early infant diets. The objective of this review, which is part of the NUTRIMENTHE research project ‘The effect of diet on the mental performance of children’ ( www.nutrimenthe.com ), was to update current evidence on the effects of nutritional interventions such as iron, folic acid or n -3 long-chain polyunsaturated fatty acid (LCPUFA) supplementation during pregnancy and/or in early life on the mental performance and psychomotor development of children. In May 2014, we searched MEDLINE and The Cochrane Database of Systematic Reviews for relevant studies published since 2009. The limited updated evidence suggests that iron supplementation of infants may positively influence the psychomotor development of children, although it does not seem to alter their mental development or behaviour. The use of multivitamin-containing folic acid supplements during pregnancy did not benefit the mental performance of the offspring. Evidence from randomised controlled trials (RCT) did not show a clear and consistent benefit of n -3 LCPUFA supplementation during pregnancy and/or lactation on childhood cognitive and visual development. Caution is needed when interpreting current evidence, as many of the included trials had methodological limitations such as small sample sizes, high attrition rates, and no intention-to-treat analyses. Taken together, the evidence is still inconclusive. Large, high-quality RCT to assess the effects of supplementation with iron, LCPUFA or folic acid are still needed to further clarify the effects of these, and other nutrients, on neurodevelopment. Recent recommendations from scientific societies are briefly presented.
Article
Homeostasis of reactive oxygen species is required to maintain sperm maturation and capacitation. Docosahexaenoic acid (DHA) is accumulated in testicles and spermatozoa and has the ability to manipulate the redox status. The effects of dietary n-3 polyunsaturated fatty acid (n-3 PUFA) deficiency from early life to adulthood on the physiological and functional properties of males under the redox imbalance of testicular tissue deserve attention. The consecutive injection of hydrogen peroxide (H2O2) and tert-butyl hydroperoxide (t-BHP) for 15 days to induce oxidative stress in testicular tissue was used to elucidate the consequences of testicular n-3 PUFA deficiency. The results indicated that reactive oxygen species treatment in adult male mice with DHA deficiency in the testis could reduce spermatogenesis and disrupt sex hormone production, as well as trigger testicular lipid peroxidation and tissue damage. N-3 PUFA deficiency from early life to adulthood resulted in higher susceptibility to testicular dysfunction in the germinal function of supplying germ cells and the endocrine role of secreting hormones through the mechanism of aggravating mitochondria-mediated apoptosis and destruction of blood testicular barrier under oxidative stress, which might provide a basis for humans to reduce susceptibility to chronic disease and maintain reproductive health in adulthood through dietary interventions of n-3 PUFAs.
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The archaeological evidence of flax cultivation dates back to >6000 BC and it is considered as one of the oldest and most useful crops. Components of flax have diverse uses. Cultivar development of flax is currently focused on enhancing the oil content and nutritional value to meet the demand of nutraceutical market supply, as an alternate source of fish oil, a rich source of eicosapentaenoic acid (EPA, C20:5) and docosahexaenoic acid (DHA, C22:6). Growing awareness about the role of diet and quest for human wellness has fuelled interest in ‗Functional foods‘ and functional attributes of many traditional foods are being reinvented. Flaxseed is cultivated in many parts of world for fiber, oil as well as for medicinal purposes and also as nutritional product. Flax continues to surge forward in its recognition as a functional food. It is the richest known source of alpha-linolenic acid, the phytoestrogen, lignans, as well as being a good source of soluble fiber. Flax is also very important fibrous bast plant, both for valuable textile fibres and composites applications and for bioactive compounds used in folk medicine, nutraceuticals and functional food. Flax seeds are rich in valuable fatty acids, amino-acids, phytoestrogens, cyclolinopeptides, lecithin, waxes, lignin, pectin, mucilage, etc. ω-3 and ω-6 polyunsaturated fatty acids (PUFA) are effective preventing cardiovascular and heart diseases. The flax seed has been shown to possess significant antioxidant and anti-inflammatory functions. In this review, composition, essential fatty acids,omega-3 fatty acid, alpha linolienic acid, proteins, vitamins and minerals, lignans, dietary fiber and uses of flaxseed are discussed.
Thesis
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Background Due to high attrition in randomised controlled trials (RCTs), cognitive effects of infant formula modifications remain uncertain. The aim of this thesis was to test a new method to minimise attrition and, through doing so, to compare differences in academic performance between children previously randomised to either nutritionally modified or standard infant formula. Methods Nine dormant infant formula RCTs conducted in England (1982-2001) were available for linkage to the National Pupil Database. Linkage was based on legal exemption from the need for participant consent. A trusted third party provided de-identified data for up to four candidate pupil matches per participant and agreement-metrics for all shared linkage variables. I completed the linkage of de-identified data, using auxiliary RCT variables and probabilistic methods. Six RCTs (n=1,563) were eligible for analysis, and a further three RCTs were used to assess linkage success and improve multiple imputation of missing data. Participant academic performance was measured using exam grades, with the primary outcome being General Certificate of Secondary Education (GCSE) Maths grades at age 16 years. Modified formula and standard formula groups were compared on an intention-to-treat basis, stratified by trial. Results Within the six trials eligible for analysis, primary outcome data was available for 86% of all participants. Available outcome data was substantially higher than the average of 22% above age 2 years in previous consent-based cognitive follow-ups of the trials. There was no evidence of benefit for GCSE Maths performance for any type of modified formula. Secondary academic outcomes provided weak evidence of harm for one of the formula modifications. Conclusions Unconsented linkage of dormant trials to administrative education data is feasible and leads to higher follow-up rates compared to traditional consented follow-up methods. None of the investigated nutritionally modified formula interventions improved academic performance.
Chapter
The association between low omega-3 polyunsaturated fatty acid (PUFA) intake and visual dysfunction has been well documented (Vingrys et al., 2001; SanGiovanni and Chew, 2005; Singh, 2005). This chapter reviews recent research that provides insights into the mechanisms through which these essential fatty acids can act to modulate neural function. A brief overview of the importance of dietary omega-3 fatty acids in sustaining ocular health precedes a discussion of the functional contribution that omega-3 PUFA have as structural components of membranes. The specialized metabolism of these lipids by the retina as well as its accessibility by way of electroretinography render this tissue a useful model in which to consider the functional consequences of omega-3 de+ ciency. These functional losses are discussed with respect to the roles that omega-3 polyunsaturates are known to have in modulating membrane biophysical characteristics and membrane-bound protein function. Laboratory trials indicate that omega-3 metabolites should impact on membranebound protein activity in a predictable fashion, although in vivo animal or human studies fail to consistently demonstrate these effects. This review details possible explanations for the lack of concordance between the in vivo and in vitro outcomes.
Article
Lines of evidence have demonstrated that early-life malnutrition is highly correlated with neurodevelopment and adulthood neuropsychiatric disorders, while some findings are conflicting with each other. In addition, the biological mechanisms are less investigated. We systematically reviewed the evidence linking early-life nutrition status with neurodevelopment and clinical observations in human and animal models. We summarized the effects of special nutritious on neuropsychiatric disorders and explored the underlying potential mechanisms. The further understanding of the biological regulation of early-life nutritional status on neurodevelopment might shed light on precision nutrition at an integrative systems biology framework.
Article
All infants were fed their own mother's milk, and in case of insufficient breast milk, formula feeds were used to meet the total energy requirements on that particular day. Babies who needed more than 15% of energy from formula feeds for more than two days were not included in this study. Milk was expressed by the mothers using Medela breast pump (Medela AG, Medical Technology, Switzerland). Infants were started on feeds as soon as clinical conditions permitted. When the infants tolerated a volume of >140 mL/kg/day by the enteral route, the milk in the fortifier group was enriched with a multinutrient fortifier in the form of a powder in packets, manufactured by a leading multinational drug company. Fortification was started with 1 g of fortifier added to 100 mL of milk on day 1, and gradually increased to 4 g of fortifier added to 100 mL on day 3 or 4 to improve tolerance of fortified milk. Feedings were initially given by continuous and later by intermittent gavage feeding, and finally the infants were cup and breast fed before discharge. Maximum enteral milk intake was kept at 180 mL of milk/kg/day until the infants were breast fed. The nutrient content of 100 mL of fortified human milk (with 4 g of fortifier) and mother's milk at two weeks postpartum is shown in Table 1.
Article
The purpose of this study was to evaluate changes in the quality characteristics of mackerel fish fillet under freezing storage conditions. The changes in product quality were determined by measuring pH, volatile basic nitrogen (VBN); thiobarbituric acid (TBA), lightness (L^*), redness (a^*), yellowness (b^*) values, shearing force, and microbiological evaluation (Total Plate Count, TPC) during 21 days of storage at -20, -5, and -1^{\circ}C, and their shelf-lives were established. TPC as an effective quality indicator was used to estimate the shelf-life via linear regression analysis. The TPC increased steadily with increasing storage periods at every temperature (p (r
Chapter
Fatty acids are distinguished from each other on the basis of their chemical structure. All have a chainlike structure with an acid or carboxyl group (HO-C=0) at one end and a methyl group (CH3) at the other. The rest of the molecule consists of a hydrocarbon (CH2) chain varying in length from 2 to 20 or more carbons. The most common fatty acids in foods have an even number of carbon atoms ranging from 12 to 22 carbons, though shorter, longer, and odd-numbered fatty acids exist.
Chapter
Retinal dystrophies are a heterogeneous group of ocular disorders that result in varying degrees of progressive peripheral or central visual loss.1 Though these dystrophies have traditionally been distinguished by their histopathology, ophthalmoscopic findings, and associated physiologic deficits, advances in genetics and molecular biology have permitted researchers to elucidate the genetic determinants of these clinical and histopathological changes. Techniques such as genetic linkage analysis, positional cloning, and the candidate gene approach have been utilized to associate genomic loci and specific mutations with known disease phenotypes.
Chapter
Composition of the brain is unique in its high concentration of lipid and particularly long-chain polyenoic fatty acids of the omega-6 and omega-3 series. Lipids and fatty acids have an important role in the structural integrity of cellular membranes and as messengers in cell signaling systems. Thus, the composition and balance of these molecules in the brain are critical to the proper development and functioning of the nervous system. Research has shown dietary alterations of omega-6 and omega-3 series fatty acids can trigger dramatic alterations in brain lipid composition. These alterations are associated with changes in physical properties of membranes, alterations in enzyme activities, receptors, carrier-mediated transport, and cellular interactions. This chapter discusses the effects of diet on cell membranes and cell signaling systems; brain growth; brain lipid composition and the synthesis of specific brain lipids, including reference to glycolipids and gangliosides; brain fatty acid synthesis; essential fatty acids and brain development; and the effects of deficiency, excess and balance in terms of ratios and absolute amounts. It discusses the response of the developing brain, specifically the phosphoglycerides in brain cells and brain regions, to diet formulations varying in omega-6/omega-3 fatty acid ratios within the range recommended for infant formulas. Thus, even a variation of omega-6 and omega-3 fatty acids between 4:1 and 7:1 can dramatically affect the lipid composition of the developing brain. In this regard it is important to optimize diet-induced alterations during brain development.
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Docosahexaenoic acid (DHA) accumulates in nerve endings of the brain during development. It is released from the membrane during ischemia and electroconvulsive shock. DHA optimizes neurologic development, it is neuroprotective, and rat adrenopheochromocytoma (PC12) cells have decreased PLA2 activity when DHA is present. To characterize DHA metabolism in PC12 cells, media were supplemented with [3H]DHA or [3H]glycerol. Fractions of nerve growth cone particles (NGC) and cell bodies were prepared and the metabolism of the radiolabeled substrates was determined by thin-layer chromatography. [3H]glycerol incorporation into phospholipids indicated de novo lipid synthesis. [3H]DHA uptake was more rapid in the cell bodies than in the NGC. [3H]DHA first esterified in neutral lipids and later in phospholipids (phosphatidylethanolamine). [3H]glycerol primarily labeled phosphatidylcholine. DHA uptake was compartmentalized between the cell body and the NGC. With metabolism similar to that seen in vivo, PC12 cells are an appropriate model to study DHA in neurons.
Chapter
The rubber tree is a perennial plantation crop, although in many parts of Africa the tree exists in a semi-wild state, the original rubber plantations having fallen into a state of neglect. The tree grows in hot, humid climates, maturing in about 5 years and can be tapped for rubber latex for up to 20 years. About four seeds are borne in a dehiscent fruit which, on drying, disperses the seeds by an explosive mechanism. The Nigerian Rubber Research Institute estimates that seed yield from rubber plantations varies from 100 to 150 kg/ha, depending on soil fertility and crop density. Most humid tropical countries grow or are capable of growing the rubber tree to some extent. Estimates of rubber seed production from 200 000 ha of rubber plantations in Nigeria are about 20 000 tonnes per annum. Yields of kernel from rubber seeds range from 57% to 63%, with a mean of 60.5% and current estimates (Nwokolo and Akpapunam, 1986) are that Nigeria’s rubber estates are capable of yielding 12 000 tonnes of full-fat rubber seed meal annually. This in turn, can yield about 5500 tonnes of rubber seed oil and about 6000 tonnes of defatted protein meal for animal and human nutrition. Most countries of West and Central Africa have considerable land areas under rubber tree plantations. In West Africa, Liberia has an even more extensive hectarage under rubber than Nigeria. Countries of South East Asia and Latin America, which currently produce most of the natural rubber of the world, have tremendous potential to produce rubber seed oil and rubber seed protein for human and animal use.
Chapter
The question of whether ω3FA are essential nutrients in human development has been discussed in Chapter 1 and reviewed recently (Innis 1991; Nettleton 1993). Although existing data can be criticized for not being definitive or failing to demonstrate deficiency symptoms unequivocally, researchers active in this area are taking the position that ω3FA are essential for the optimum development of neural tissues in fetal development (Carlson and Salem 1991; Hoffman and Uauy 1992; Innis 1992). The most convincing data come from studies on premature infants and measurements in neural tissues. Measurement of red blood cell fatty acid composition and serum phospholipid fatty acids are important tools, as an indirect reflection of neural tissue composition and the availability of ωFA.
Chapter
Dietary intake of fatty acids may be related to dementia and cognitive function through a number of plausible mechanisms, such as atherosclerosis and thrombosis, inflammation, via an effect on brain development and membrane functioning, or via accumulation of beta-amyloid. This review gives an overview of the few studies that have investigated the relationship between fatty acid intake (including the fatty acids from fish) and cognitive function or dementia. The most consistent findings so far are a positive association between saturated fat, cholesterol, and dementia or cognitive impairment and an inverse association between fish or n-3 fatty acids and dementia or cognitive impairment. Additionally, limitations on dietary intake studies and possible mechanisms behind the investigated associations are discussed. Since diet is a risk factor that is suitable for intervention these results are hopeful and potentially very important. This chapter was based on a review published in The Journal of Nutrition, Health & Aging 2000;4:202–207 by Kalmijn S, entitled ‘Fatty acid intake and the risk of dementia and cognitive decline: a review of clinical and epidemiological studies.’
Chapter
Excess dietary fatty acids and excess dietary carbohydrate are stored in adipose tissue as triacylglycerols. Insulin is the major hormone that stimulates this process of fat storage. Fatty acids are a prime fuel for humans and lower animals; they can be stored as triacylglycerols in large amounts in fat cells.
Article
Background and objective: Long-chain polyunsaturated fatty acids, especially docosahexaenoic acid, have been suggested as a nutrition factor affecting visual and neurobehavioral development of preterm infants. Several randomized controlled trials (RCTs) have investigated the effect of supplementation of long-chain polyunsaturated fatty acids on preterm infants. We conducted a systematic review and meta-analysis to examine the efficacy of long-chain polyunsaturated fatty acid supplementation of formula or breast milk on the neurodevelopment outcomes of preterm infants. Methods: Two authors searched PubMed and Cochrane Library (CENTRAL) for RCTs assessing efficacy of long-chain polyunsaturated fatty acids supplementation on the neurobehavioral and development outcomes of preterm infant. Human RCTs which supplemented long-chain polyunsaturated fatty acids during lactation and assessed neurodevelopment were included. The quality of each RCT was assessed, and the results of eligible trials were included in the systematic review and meta-analysis. Results: We included 11 RCTs with 2272 total participants. Methodologic limitations existed to some extent in most RCTs that were included. Because the age of the participants from different trails was not the same, different scales and indexes had been assessed from different RCTs. Our meta-analysis indicated a significant effect of long-chain polyunsaturated fatty acids supplementation on the neurodevelopment of preterm infants assessed by the Mental Development Index of the Bayley Scales at one to three years of age versus the control groups. Conclusion: Analysis of our consolidated data indicates that long-chain fatty acid supplementation results in a significant improvement in the neurodevelopment of preterm infants as assessed by the Mental Development Index at one to three years of age. The available evidence suggests that long-chain polyunsaturated fatty acid supplementation during lactation may accelerate the pace of neurodevelopment in preterm infants, although their final developmental outcome may be unchanged.
Chapter
Fats and oils (collectively called lipids) constitute a substantial portion of our diets. About 35–40% of dietary energy (Europe, North America) comes from fat. Fat, at about 9 cal/g, is calorically dense compared to both protein and carbohydrate at about 4 cal/g. About 95% of dietary fat is composed of triglycerides. The remaining portion of fat in our diets is made up of other lipids such as cholesterol and phospholipid. Fatty acids are the building blocks of the majority of these lipids. Recently, much interest has been focused on the types of fatty acids in our diets, including saturated, mono-unsaturated, and polyunsaturated fatty acids (including both the ω-6 and ω-3 types). Nutritionally, the only essential lipids in our diets are the so-called essential fatty acids, linoleic acid (ω-6) and some ω-3 (linolenic acid and/or docosahexaenoic acid). The advent of hydrogenation to produce such products as margarines has introduced the unnatural trans fatty acids. Due to the concern over fat consumption, the development of fat substitutes for foods is an active area of research. Medium-chain triglycerides have been used as an alternative source of fat energy for those individuals unable to digest normal fats in the diet. These topics are discussed in detail in this chapter.
Chapter
Omega-3 (or n−3) fatty acids are accumulated in membrane phospholipids primarily as docosahexaenoate (22:6, omega-3). Brain and retina contain by far the highest concentrations of this fatty acid of any tissue. The content of docosahexaenoate is third highest in testes, but its concentration is several fold lower in that tissue than in brain and retina (Salem et al, 1986: Birkle and Bazan, 1986; Bazan and Reddy, 1985).
Chapter
It is necessary to ensure that brain cells receive adequate supplies, especially of lipids, during their differentiation and multiplication. A lipidic anomaly could result in altered function of the membranes and a greater susceptibility of the membranes to aggression, particularly toxic.
Chapter
Recognition of α-linolenic acid (LnA)* as an EFA in higher animals has been late in forthcoming, in sharp contrast to the abundance of reports demonstrating the essentiality of LA in many animal species, including humans.1 Evidence for an essential role in LnA in vision of Rhesus monkeys has been described,2 and cases of human LnA deficiency have been reported3.
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In this study, the effects of water current on omega-3 (n-3) fatty acids of trout (Oncorhynchus mykiss) were investigated. Compared with group B the fish of group A showed a higher content of the individual n-3 fatty acids C18:3 n-3, C18:4 n-3, C20:4 n-3, C20:5 n-3 (p<0.05) and a lower content of C22:6 n-3 which was, however, compensated as a result of the total share of n-3 fatty acids.
Article
Essential oils are reported to have a wide range of biological activity. However till now only a few investigations have been carried out to study an in vivo effect of essential oils application. We studied the effect of essential oil composition given to mice in drinking water on its fatty acid composition of brain and liver. We found that content of fatty acids in mice liver and brain depends both on the animal's age and on concentration of tested essential oils in drinking water.
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The fatty acid compositions of Tilapia rendalli, T. zilli and Oreochromis aurea reared in cages located in Seyhan Dam Lake, O. niloticus reared in freshwater ponds and Tilapia spp. from the Seyhan River were compared. The fatty acid levels of Tilapia spp. from the Seyhan River were significantly higher than those of the other groups (p < 0.05). Total ω-3 fatty acid values were significantly different for all groups and the highest level were found in Tilapia spp. (p < 0.05). The ratio of ω-3/ ω-6 for Tilapia spp., O. aurea, T. rendalli, T. zilli and O. niloticus were 1.95, 1.37, 1.29, 1.21 and 1.12, respectively.
Article
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Gray matter, white matter, and myelin were isolated from the frontal lobes of the brains of humans aged 10 months, 6 yr, 9 yr, and 55 yr. The major lipids, including ethanolamine glycerophosphatides (EGP), serine glycerophosphatides (SGP), choline glycerophosphatides (CGP), sphingomyelin, cerebroside, cerebroside sulfate, and ceramide were isolated by column chromatography and their fatty acid and fatty aldehyde compositions were determined by gas–liquid chromatography. EGP and SGP from myelin had a fatty aldehyde composition which differed from that of EGP and SGP from gray matter; octadecenaldehydes were present in much higher proportions in these lipids from myelin than in those from gray matter. EGP and SGP also contained high proportions of 20- and 22-carbon polyunsaturated fatty acids, whereas CGP contained small proportions of these acids. Each glycerophosphatide from gray matter contained approximately 3- to 6-fold higher proportions of polyunsaturated fatty acids than did the same glycerophosphatide from myelin. Sphingomyelin, cerebroside, cerebroside sulfate, and ceramide also differed in their fatty acid compositions depending upon their tissue source; each sphingolipid from myelin in the younger subjects contained 5- to 9-fold higher proportions of long-chain fatty acids (C19-C26) than did the same sphingolipid from gray matter. The lipids from myelin in the baby (10 months) were very similar to those from myelin in the adult, both with respect to their content of polyunsaturated fatty acids and to their content of long-chain fatty acids. These findings suggest that myelin in the baby is “chemically mature” in its lipid composition at an early age.
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Docosahexaenoic acid [22:6 omega 3; 22:6-(4,7,10,13,16,19)] is the major polyunsaturated fatty acid in the photoreceptor membranes of the retina and in cerebral gray matter. It must be obtained either from the diet or by synthesis from other omega 3 fatty acids, chiefly alpha-linolenic acid (18:3 omega 3). We tested the effect of dietary omega 3 fatty acid deprivation during gestation and postnatal development upon the fatty acid composition of the retina and cerebral cortex and upon visual function. Rhesus monkeys (Macaca mulatta) were fed semipurified diets very low in 18:3 omega 3 throughout pregnancy, and their infants received a similar diet from birth. A control group of females and their infants received a semipurified diet supplying ample 18:3 omega 3. In near-term fetuses and newborn infants of the deficient group, the 22:6 omega 3 content of phosphatidylethanolamine was one-half of control values in the retina and one-fourth in cerebral cortex. By 22 months of age, the content of 22:6 omega 3 in these tissues approximately doubled in control monkeys, but it failed to increase in the deficient group. Low levels of 22:6 omega 3 in the deficient animals' tissues were accompanied by a compensatory increase in longer-chain omega 6 fatty acids, particularly 22:5 omega 6. Functionally, the deficient animals had subnormal visual acuity at 4-12 weeks of age and prolonged recovery time of the dark-adapted electroretinogram after a saturating flash. Abnormally low levels of 22:6 omega 3 may produce alterations in the biophysical properties of photoreceptor and neural membranes that may underlie these functional impairments. The results of this study suggest that dietary omega 3 fatty acids are retina and brain.
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Although xerophthalmia due to severe vitamin A deficiency is the leading cause of childhood blindness in the underdeveloped countries, little is known about the proteases (other than collagenase) that are involved in the degradative mechanism. The degree of cellular autolysis and stromal degradation observed histologically in early stages of xerophthalmia and in ulcerating corneas in vitamin A deficient rabbits in this study were, in general, proportional to the levels of the proteases studied. The only major histologic and ultrastructural alteration observed in early xerophthalmic corneas was autolysis of superficial epithelial and stromal cells. In contrast, in the ulcerating corneas the stroma was infiltrated heavily with inflammatory cells and extensive stromal degradation was observed in the central necrotic region of the lesions. Maximal proteolytic activity toward hemoglobin was observed at pH 3.3 for corneal extracts from normal (N) and pair-fed control (C) rabbits and rabbits with early xerophthalmia (X) and ulcerating xerophthalmia (U) corneas. This activity was a cathepsin D-like enzyme per cornea that had a ratio of 1:1:3:16 in the N, C, X, and U corneas. The ratio of cathepsin B-like activity per cornea for N, C, X, and U corneas was 1:2:2:10.
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Membrane fatty acid composition, phospholipid composition, and cholesterol content can be modified in many different kinds of intact mammalian cells. The modifications are extensive enough to alter membrane fluidity and affect a number of cellular functions, including carrier-mediated transport, the properties of certain membrane-bound enzymes, binding to the insulin and opiate receptors, phagocytosis, endocytosis, depolarization-dependent exocytosis, immunologic and chemotherapeutic cytotoxicity, prostaglandin production, and cell growth. The effects of lipid modification on cellular function are very complex. They often vary from one type of cell to another, and they do not exert a uniform effect on all processes in a single cell line. Therefore, it is not yet possible to make any generalizations or to predict how a given system will respond to a particular type of lipid modification. Many of the functional responses probably are caused directly by the membrane lipid structural changes, which affect either bulk lipid fluidity or specific lipid domains. The conformation or quaternary structures of certain transporters, receptors, and enzymes probably are sensitive to changes in the structure of their lipid microenvironment, leading to changes in activity. Prostaglandin production is modulated by the availability of substrate fatty acids stored in the membrane phospholipids, but the underlying chemical mechanism still involves a change in membrane lipid structure. While this is the most likely mechanism, the possibility that the membrane lipid compositional change is an independent event that occurs concurrently but is not causally related to the functional perturbations also must be considered.
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A thin-layer chromatographic procedure for the isolation of tissue phospholipids and their subsequent analysis is described. The method has been applied to the determination of the fatty acids of phosphoglycerides in human brain from the early fetal stage to old age. The study shows changes in the distribution and fatty acid composition of each phosphoglyceride in normal brain, although they are quite small after early childhood. A lipid-specific fatty acid pattern for each of the four major phosphoglycerides was found. Besides this, the pronounced differences between fatty acids of the lipids from the cerebral cortex and from the adjacent white matter justify speaking of a tissue-specific. fatty acid pattern for brain phosphoglycerides. The phospholipids of cerebral white matter contained more monoenoic acid but much less polyunsaturated fatty acid than those of cerebral cortex. The brain phosphoglycerides also showed an age-dependent fatty acid pattern. With increasing age the concentration of the fatty acids of the linoleate family diminished while that of the linolenate family increased. Brain inositol phosphoglycerides, the fatty acid composition of which has not been studied systematically before, were characterized by a large concentration of arachidonate which was nearly as high for white as for gray matter and showed only small changes with age.
Article
This statement proposes recommendations toward increasing the practice of breast feeding. Specific recommendations made for standards of infant formulas as to calorie, protein, fat, vitamin, and mineral levels apply to both milk-based and milk-substitute infant formulas. Such formulas, when used in place of breast-feeding, must supply most or all of the nutrients infants require during the first weeks or months of life. The minimum levels of nutrients per 100 kcal recommended for formulas provide good growth and development in healthy, full-term infants; distinct hazards may be encountered at levels below these. However, no significant advantage is to be gained by providing levels in excess of these minima in normal infants. Recommendations for maximum levels are made only where quantities in excess lead to toxicity; generally, levels near the minima recommended are most desirable because they are the most likely to reflect the composition of human milk, and the least likely to result in any undesirable nutrient to nutrient interaction. The recommendations also can be used as reference standards for formulas for special dietary uses of "medical" formulas. The Committee recommends that "medical" formulas be classified by FDA into a special group under the paragraph dealing with infant formulas.
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A 6-yr-old girl who lost 300 cm of intestine was maintained by total parenteral nutrition. After 5 months on a preparation rich in linoleic acid but low in linolenic acid she experienced episodes of numbness, paresthesia, weakness, inability to walk, pain in the legs, and blurring of vision. Diagnostic analysis of fatty acids of serum lipids revealed marginal linoleate deficiency and significant deficiency of linolenate. When the regimen was changed to emulsion containing linolenic acid neurological symptoms disappeared. Analysis indicated that linoleate deficiency had worsened but linolenate deficiency had been corrected. The requirement for linolenic acid is estimated to be about 0.54% of calories.
Article
— A comparative study of the concentration and fatty acid distribution in diacyl- and triacylgly-cerols. free fatty acids and total phospholipids from rabbit, cattle and toad retina is presented. With respect to the toad, a comparison is made with brain, choroid and plasma lipids. Marked differences in diacylglycerol composition and levels between mammalian and toad retina are found: in the mammal arachidonate predominates (25 per cent), in the toad docosahexaenoate is the main fatty acid (42 per cent). The total phospholipid composition parallels that of the diacylglycerols only in the toad, whereas in the mammalian retina the phospholipids are richer in docosahexaenoate than are the diacylglycerols. It is suggested that there is a relationship between diacylglycerols and phosphoglyceride metabolism in the toad; in the retinas of other species the diacylglycerols may be related to specific phosphatides. In the three species, triacylglycerols show high levels of unsaturation; however, marked differences are found in the distribution of polyunsaturated acyl groups: in the cattle and toad retina docosahexaenoate predominates. whereas in the rabbit a higher proportion of 22:4 is found. Retina free fatty acid pools also show different features in the three species: the cattle retina contains the highest proportion of free 20:4 and 22:6. The triacylglycerol concentration is much higher in the toad choroid than in the retina, although the fatty acid compositions are similar. A possible relationship between these choroid lipids and those of the retina is suggested.
Article
The essential fatty acid requirement for normal pupal-adult ecdysis in Galleria mellonella was studied using non-axenic casein-based semisynthetic diets with or without various 99% pure fatty acids. The abilities of linoleic and linolenic acids to alleviate faulty adult emergence differed markedly, linolenic acid being 10-fold more potent than linoleic acid. One other ω6 polyunsaturated fatty acid, C20:2ω6, resembled its analogue, linoleic acid (18:2ω6), in efficacy at high dosage, but three others, C18:3ω6, C20: ω6 and C20:4ω6 (arachidonic acid), were without effect. Of five ω3 polyunsatures tested, C22:3ω3 and C20:3ω3 were as effective as linolenic acid (C18:3ω3), their shorter-chained analogue. Docosahexaenoic acid (C22:6ω3) was totally ineffective, but eicosapentaenoic acid (C20:5ω3), though supporting no perfect emergences, produced some active adults having wing malformations only, and was therefore considered partially active. It is suggested that a C18 polyunsaturate is physiologically required by G. mellonella and can be derived from various dietary longer-chained analogues by simple carbon chain shortening so long as there are no additional double bonds carboxylwards of an active di- or trienoic sequence. The partial activity of C20:5ω3 suggests there may additionally be a physiological requirement for this or a related long-chain polyunsaturate. The possibility of multiple essential fatty acid requirements in Lepidoptera in general is discussed.
Pregnant rats were fed diets supplemented with oils rich either in n−6 (safflower oil) or in n−3 fatty acids (fish oil).This dietary treatment was continued with the weaned rats up to 90 days of age. The fatty acid composition of brain ethanolamine phosphoglyceride was analyzed at 15, 30, 60 and 90 days of age, in both groups of rats.It was confirmed that: 1.1. Fatty acids of the n−6 and n−3 families undergo reciprocal replacement in the ethanolamine phosphoglyceride molecule according to the dietary levels of these acids.2.2. The desaturating steps in the metabolic conversion of linoleic (n−6) acid are mainly affected in animals fed with high levels of n−3 acids. This is also true in brain. It was found that :3.3. Dietary polyunsaturated, long chain fatty acids of the n−3 family enter the brain and became involved in the metabolism of fatty acids of brain phospholipids.4.4. The levels of unsaturation of brain ethanolamine phosphoglyceride fatty acids is constant in both groups of rats.
Article
Diets free of fat were fed to 9 Cebus monkeys for periods ranging from 8 to 22 months, and diets containing 8% by weight as corn oil were fed to 4 Cebus monkeys. Differences in fatty acid composition and cholesterol concentrations in a wide variety of tissues were determined and their significance discussed. A detailed histological examination of the monkeys was also made. Many of the biochemical and some of the histological changes characteristic of fat deficiency in rats were observed in the Cebus monkeys. The accumulation of increased concentrations of cholesterol esters in the liver and adrenals, which is characteristic of fat deficiency in rats, was not observed in the Cebus monkeys fed diets devoid of fat.
Article
Neural cell membranes naturally contain a large amount of polyunsaturated fatty acid, but the functional significance of this is unknown. An increase in membrane polyunsaturation has been shown previously to affect the high-affinity transport systems for choline and glycine in cultured human Y79 retinoblastoma cells. To test the generality of membrane polyunsaturation effects on transport, we investigated the uptake of other putative neurotransmitters and amino acids by these cells. Taurine, glutamate, and leucine were taken up by both high- and low-affinity transport systems, whereas serine, γ-aminobutyrate, and α-aminoisobutyrate were taken up only by low-affinity systems. The high-affinity taurine and glutamate and low-affinity serine uptake systems were Na+ dependent. Arachidonic acid (20:4) supplementation of Y79 cells produced enrichment of all the major microsomal phosphoglycerides with 20:4, while docosahexaenoic acid (22:6) supplementation produced large increases in the 22:6 content of all fractions except the inositol phosphoglycerides. Enrichment with these polyunsaturated fatty acids facilitated taurine uptake by lowering the K′ of its high-affinity transport system. By contrast, enrichment with oleic acid did not affect taurine uptake. Glutamate, leucine, serine, γ-aminobutyrate, and α-aminoisobutyrate uptake were not affected when the cells were enriched with any of these fatty acids. These findings demonstrate that only certain transport systems are sensitive to the polyunsaturated fatty acid content of the retinoblastoma cell membrane. The various transport systems either respond differently to changes in membrane lipid unsaturation, or they are located in lipid domains that are modified to different extents by changes in unsaturation.
Article
Methods for isolation and characterization of subcellular particles as well as procedures for analysis of lipid class composition are discussed. The literature on distribution of lipids in subcellular particles is then reviewed. Pertinent new data from our laboratories are presented as well. The isolated particles are related to the organelles to which they correspond in the cell and are discussed with regard to heterogeneity and morphological integrity. Confusion can arise with regard to subcellular particles unless it is appreciated that: 1) preparation of particles of high purity generally requires more than the classical differential centrifugation scheme (both differential and gradient centrifugation may be required); 2) it is hazardous to apply exactly the same procedure for all tissues; 3) all subcellular fractions must be thoroughly characterized. The more recently devised DEAE cellulose column and thin-layer chromatographic procedures for analysis of lipid class composition are more reliable than the older hydrolytic or silicie acid column or paper chromatographic techniques. The chief lipid components of mitochondria from all organs and species are lecithin, phosphatidyl ethanolamine, and cardiolipin (diphosphatidyl glycerol). Despite the fact that reports in the literature are in agreement that phosphatidyl inositol is a major component of mitochondria, it is concluded on the basis of new data obtained from highly purified mitochondria and improved analytical methods that phosphatidyl inositol is not a major component of mitochondria. The presence of a relatively large amount of phosphatidyl inositol in mitochondrial preparations is probably related in part to contamination with other particles. Some analytical procedures are demonstrated to give erroneous values for this lipid class. It is also concluded that phosphatidyl serine, phosphatidic acid, sphingomyelin, cerebrosides, and lysophosphatides, reported to occur in mitochondria, are not characteristic mitochondrial components and furthermore that the large amount of uncharacterized mitochondrial phospholipid reported is actually an analytical artifact. Microsomes appear to be similar to mitochondria except that cardiolipin is either low in or absent from microsomes. Available data indicate nuclei to be rather similar to mitochondria and microsomes, at least in some organs. Studies of the fatty acids of subcellular particles indicate that different particles from one organ have very similar fatty acid compositions. It is clear that there are marked variations in fatty acid composition of particles from different organs and from different species. Differences in dietary fat may be associated with marked changes in fatty acid composition, although brain mitochondrial lipids are largely unchanged. Each lipid class from mitochondria of most organs appears to have a fairly characteristic fatty acid composition. Cardiolipin from some organs contains primarily linoleic acid, phosphatidyl ethanolamine contains large amounts of linoleic and higher polyunsaturates, and lecithin is similar to phosphatidyl ethanolamine except that it does not contain as much arachidonic acid and/or other highly unsaturated fatty acids. New data, the first to be reported, are presented for heart mitochondrial cardiolipin, phosphatidyl ethanolamine, and lecithin. It is concluded that there are two basically different types of membranous structures. Myelin is the chief representative of the metabolically stable type of membrane structure while mitochondria represent the more labile type. The two types of membranes have very different in vivo properties and very different lipid compositions. Myelin is characterized by a high content of cholesterol and sphingolipids with more long chain saturated or monoenoic fatty acids while mitochondria are characterized by a low cholesterol content, little or no sphingolipid, and highly unsaturated fatty acids. It is clear that formulations of the myelin type membrane structure such as that of Vandenheuvel cannot apply to mitochondria. It is postulated that membrane structures intermediate between the extremes represented by myelin and mitochondria exist.
Article
Photoreceptor membrane phospholipids contain large quantities of ω3 and ω6 polyunsaturated fatty acids. Attempts to deplete these fatty acids from rod outer segments of rats by feeding a fat-free diet for 10–12 weeks were unsuccessful. Subsequent experiments showed that photoreceptor disc renewal is altered in the absence of dietary ω3 and/or ω6 fatty acids. We conclude that photoreceptor membrane renewal depends upon the availability of polyunsaturated fatty acids.Docosahexaenoic acid in photoreceptor membranes was significantly lowered by raising several generations of animals on modified fat-free diets. Electroretinographic experiments on these animals showed a decreased amplitude of the a-wave, suggesting that normal visual function is dependent upon dietary polyunsaturates.
Article
The fetal brain accumulates long-chain (C20 and 22) polyunsaturated fatty acids--arachidonic and docosahexaenoic--during cell division. De-novo synthesis of these acids does not occur and they are thought to be either directly derived from food or by metabolism from linoleic and linolenic acids, respectively. Administration of isotopically labelled linoleic and linolenic acids to pregnant guineapigs showed that only a small proportion of the label was converted to their respective long-chain polyunsaturated derivatives in the maternal liver. The proportion was increased within the phospholipids (structural lipids) by what appeared to be amultiple processing system which increased chain length and degree of polyunsaturation from maternal liver to placenta, fetal liver, and to fetal brain. Observations in man suggest a similar trend. The porportion of long-chain polyunsaturated acids increased in the phospholipids from maternal blood, cord blood, fetal liver, and fetal brain. These data show that the placenta and fetus are radically modifying the maternal phospholipids so as to achieve the high proportions of the C20 and C22 polyunsaturated fatty acids in the structural lipids of the developing brain.
Article
Continuous-sucrose gradient centrifugation of whole retina homogenates from bovine, frog and rat were found to yield two major bands of rhodopsin-containing material having distinctly different polyunsaturated fatty acid (PUFA) contents. The lowest density band has the highest purity rod outer segment (ROS) membranes and the highest PUFA content whereas the higher density band has a lower PUFA content and contains non-ROS membrane impurities. It follows, that in ROS preparations from whole retinal homogenates in which these two bands are pooled, the measured PUFA content will be lower than that of the purest ROS band. We find that the highest purity ROS band from bovine, frog and rat retinal homogenates have weight-percents of docosahexaenoic acid (22:6ω3) of 50·7±1·4, 50·9±0·6, and 46·2±3·6, respectively, which is equivalent to 47·1, 46·9, and 43·3 mol-percent. Two ROS bands were also isolated from homogenates of semipurified ROS removed from retinas by shaking (i.e. the shakate preparation). Both shakate bands have similar PUFA contents (with weight-percent 22:6ω3 of ≈51·5) and similar phospholipid: rhodopsin ratios. The more dense band has a significantly higher 280 nm/Δ500 nm ratio which probably reflects some nonrhodopsin protein retained in the ROS by the intact plasma membrane. The lowest density band has ROS with disrupted plasma membranes whereas the more dense band has intact plasma membranes. Homogenization of whole retinas introduces considerable non-ROS membrane contamination into the more dense ROS band.We have developed specific procedures (i.e. use of 0·1 mm CaEDTA and an inert argon atmosphere) that inhibit ROS lipid autoxidation and loss of PUFA. The results indicate that if adequate levels of vitamin E are present the maintenance of antioxidant conditions during preparation procedure is not a highly critical factor in determining ROS PUFA content.
Article
Rats were fed for two generations a purified, linolenic acid-deficient diet in which the only source of lipid was purified methyl linoleate. This diet contained about 38 mg linolenic acid/kg diet. Control rats were given the same diet supplemented with methyl linolenate (2,500 mg/kg diet). Male and female rats ranged in age from weaning pups to adults. Lipids were extracted from liver, brain, kidney, spleen, heart, muscle, gastrointestinal tract, lung, ovary, testis, adrenal, plasma, erythrocytes, retina, and adipose tissue. Fatty acids of major phospholipid classes (choline phosphoglycerides, ethanolamine phosphoglycerides, and mixed serine phosphoglycerides plus inositol phosphoglycerides) or of total lipid extracts were measured by gas liquid chromatography. Growth rates and organ weights were similar in control and linolenic acid-deficient rats. The major effect of the deficiency was to lower the proportions of n-3 fatty acids, especially 22:6 n-3, in all the organs analyzed. Docosahexaenoic acid (22:6 n-3) was mainly replaced by 22:5 n-6 in deficient rats. The greatest changes in composition were found in brain, heart, muscle, retina, and liver.
Article
The fatty acid composition of erythrocytes, of plasma choline phosphoglycerides, and of adipose tissue, serum cholesterol, triglyceride and vitamin B12 concentrations, weights, heights and skinfold thickness were determined on 22 vegans and 22 age and sex matched omnivore controls. The fatty acid composition of breast milk from four vegan and four omnivore control mothers, and of erythrocytes from three infants breast fed by vegan mothers and six infants breast fed by omnivore control mothers was determined. The proportions of linoleic acid and its long-chain derivatives were higher, the proportion of the long-chain derivatives of alpha-linolenic acid was lower, and the ratio of 22:5omega3/22:6omega3 was greater in the tissues of the vegans and infants breast-fed by vegans than in controls; the most marked differences were in the proportions of linoleic (18:2omega6) and docosahexenoic (22:6omega3) acids. Weights, skinfold thickness, serum vitamin B12, cholesterol and triglyceride concentrations were less in vegans than in controls. The difference in serum cholesterol concentration was most marked. It is concluded that a vegan-type diet may be the one of choice in the treatment of ischemic heart disease, angina pectoris, and certain hyperlipidemias.
Article
The earlier reports from this laboratory that the renewal of rat photoreceptor membranes was dependent on essential fatty acids have not been confirmed in more recent studies.
Article
Rats were raised for 2 generations on a diet in which 1.25% methyl linoleate was the only source of fat. Control rats were given 1.0% methyl linoleate plus 0.25% methyl linolenate. Lipids were extracted from retinas and their fatty acids were analyzed by gas-liquid chromatography. Docosahexaenoic acid accounted for 33.8% of total fatty acids in control retinas, for 13% of fatty acids in first-generation deficient retinas, and for 2.7% of fatty acids in second-generation deficient retinas.
Article
The vertebrate rod visual cell is anatomically divided into two compartments, the inner segment and the outer segment (Fig. 1). The rod inner segment contains the cellular organelles responsible for most, if not all, of the biosynthetic activity of the cell. One end of the inner segment makes synaptic contact with horizontal and bipolar cells, while the other is connected to the rod outer segments (ROS) via a short connecting cilium. The ROS are made up of hundreds of membraneous discs. Each is free-floating and apparently does not contact other discs or the plasma membrane.
Article
Female rats were fed semi-purified diets containing 10% safflower oil or 10% soybean oil for six weeks prior to mating and through-out pregnancy and lactation. The progeny were weaned to the diet of the dam. Physical, neuromotor and reflex development was monitored in the progeny prior to weaning and learning ability of the mature progeny was assessed in a simple Y-maze test. Brain lipid analyses were conducted in the progeny at birth, 21 and 210 days of age. Inclusion of soybean oil in the diet resulted in higher levels of 22:6omega3 and lower levels of 22:5omega6 in the brain ethanolamine glycerophosphatides. The nature of the dietary fat exerted no effect on the physical development, onset of reflexologic responses or onset of neuromotor co-ordination in the pups. The soybean oil-fed animals spent more time in certain neuromotor activities possibly associated with explorative drive than did their safflower oil-fed counterparts. The performance of the mature soybean oil-fed progeny in the discrimination-learning test was superior to that of progeny fed safflower oil. The association of superior learning capacity with dietary soybean oil-induced incorporation of omega3 fatty acids into the brain glycerophosphatides is offered as support for an essential role for dietary linolenic acid for the young rat.
Article
Rat electroretinograms were measured as a function of dietary supplements of purified ethyl esters of linolenic acid, linoleic acid, and oleic acid. Polyunsaturated fatty acids derived from precursors of linolenic and linoleic acids appear to be important functional components of photoreceptor cell membranes, although in equal dietary concentrations, linolenic acid precursors affect electroretinogram amplitudes to a greater extent than linoleic acid precursors. The electrical response of photoreceptor cell membranes appears to be a function of the position of the double bonds as well as a function of the total number of double bonds in fatty acid supplements.
Article
MOST vertebrate species require some dietary source of essential fatty acids (EFAs)1,2. A wide range of naturally occurring polyunsaturated fatty acids have been shown to exhibit EFA activity, but they can be classified into two homologous series characterised by the position of the terminal double bonds relative to the methyl (omega) carbon atom. The omega6 series of EFAs all have double bonds in the omega6 and omega9 positions, the omega3 series in the omega3, omega6 and omega9 positions. The metabolic interrelationships of the members of each series are shown in Fig. 1. The naturally occurring 18-carbon parent compounds for each series are linoleic acid (18:2 omega6) and linolenic acid (18:3 omega3) and EFA requirements are usually stated in terms of either or both ot these parent EFAs (p-EFAs)1,3.
Article
Biochemical studies in albino rats fed a lab chow diet (control) showed a 9 to 10 day turnover time for rhodopsin in rod photoreceptor membranes, whereas the turnover time in animals raised on a fat-free diet (experimental) was not easily measurable. The number of phagosomes in the pigment epithelium of the control group was three times that found in the experimetals. These studies support earlier autoradiographic data which suggested that the renewal of new photoreceptor discs in the rat retina is controlled by the availability of polyunsaturated fatty acids.
Article
Rats were reared into a third generation on diets deficient in essential fatty acids supplemented with linoleic acid (18:2 n-6) or linolenic acid (18:3 n-3) with the object of depleting the retina of n-6 or n-3 fatty acids. In the rats fed 18:2 n-6 the percentage by weight of 22:6 n-3 in retinal fatty acids fell from 22.5 to 8.5% in first-generation animals but then remained unchanged in second and third generations. There was no difference in b-wave amplitudes of the electroretinogram between the rats fed 18:2 n-6 and those fed 18:3 n-3. In guinea-pigs fed purified diets low in 18:3 n-3 the percentage by weight of 22:6 n-3 in retinas fell from 8 to less than 0.5% by the third generation. However, there were no statistical differences in the b-wave amplitudes between these animals and those reared on a commercial diet. It is concluded that if n-3 fatty acids are involved in retinal function their role is too subtle to be detected by standard electroretinographic techniques.
Article
Rats were fed a semisynthetic diet containing either sunflower oil or soya oil. Half the litter fed with sunflower oil diet was changed to a soya oil diet when the pups were 15 days old (during active myelination). Fatty acid analysis was then performed on subcellular fractions of the animals fed (a) soya oil, (b) sunflower oil, and (c) soya oil replacing sunflower oil from the 15th day, to determine the speed of the recovery. All material from animals fed sunflower oil showed an important reduction in docosahexaenoic acid (22:6 n-3), compensated by an increase in docosapentaenoic acid (22:5 n-6), whereas arachidonic acid (20:4 n-6) was not affected. In all fractions examined, when sunflower oil was replaced by soya oil in 15-day-old pups the recovery started from the very first day but lasted more than 2 months (this recovery was determined by the increase of 22:6 n-3 up to the normal value and decrease of the 22:5 n-6). In addition a delay was found for myelin recovery, starting only from the 25th day.
Article
Three studies published in this issue of the Journal support the possibility that the consumption of fish may be of special benefit to human health. One of the studies1 shows that the consumption offish by a group of Dutch men correlated inversely with death due to heart disease during a 20-year follow-up period. This result is of special interest because it was obtained with a prospective approach, because an average daily intake of only 30 g offish had a substantial protective effect, and because the relation between fish consumption and death from coronary heart disease seemed to be independent of . . .
Article
Eight capuchins approximately 8 to 12 mth old were maintained on diets supposed to contain all the essential dietary elements, with only the intake of vitamin D subject to variation. Essential fatty acid (EFA) requirements were supplied by corn oil. All the monkeys developed skin lesions, and two were destroyed after self mutilation. EFA deficiency was suspected from the symptoms and organ histology. Analyses of red cell membranes and biopsy and autopsy samples of tissues suggested a specific linolenic acid deficiency. Complete recovery occurred when purified linseed oil was added to the diet.
Article
Three decade s ago nutritional investigation of insects had developed to the point of describing complete qualitative dietar y requirements of several nonfastidious spe cies that readily accepted chemically defined diets, allowing individually deleted nutrients to be assessed in terms of growth and develop­ ment. The antece dents of this phase of insect nutrition may be traced in earl y reviews (41, 197, 274,275, 299). Subsequent proliferation of studies enabled a recent tabular summary (6) to list nutrient requirements of about forty species, diverse in taxonomy and feeding habit s, and notably including sev­ eral plant-feedin g insects, a category long intractable to dietary manipulation. Such a wealth of consolidatory information affords a substantial basis for generalizing the nutritive needs of the class as a whole. The conclusions, many sti ll valid, may be examined in a sequence of general review (65, 73, 149, 150, 153,248), augmented by specialized discussions of parasitic insects (148), phytophagous insects (45, 105, 282), nutr itional pathology (151), nutrition and resistance to biochemicals (125), silkworms (165, 305), m os­ quitoes (54), grasshoppers (60), Diptera (106), bees (132), and plant-suck­ ing insects (10, 11, 207). Information on bulk digestibility and utilization of natural and artificial foods, scattered throughout the foregoing reviews, was recently summarized and critically discussed (126, 296). The impact of sym­ biotic microorganisms on host nutrition has been surveyed (35, 90, 134), as has the bearing of physical and gustatory attributes of experimental diets on the inter pretation of nutritional studies
Article
The lipid composition of synaptic vesicles isolated from adult rat brain was determined. Vesicles contained cholesterol and phospholipid but very little ganglioside, galactolipid, free fatty acid and triglyceride was detected. Ethanolamine and choline phosphoglycerides were the dominant phospholipids. Lysophosphatidyl choline was present in very low amounts. The fatty acid composition of the phosphoglycerides was characterized by high levels of docosahexaenoic acid in the ethanolamine and serine phosphoglycerides, and the absence of long chain fatty acids from the sphingomyelins. All the characteristic features of the lipid composition of the synaptosomal plasma membrane (with the exception of the ganglioside content) were seen in the synaptic vesicle lipids. The results are discussed in terms of the exocytosis mechanism of transmitter release.
Article
Brain monoamine oxidase and 5′-mononucleotidase activities were decreased to 57.0% and 37.6% of control values respectively in rats after a four month period of lipid deprivation. Glucose-6-phosphatase activity increased. On refeeding with either linoleic or linolenic acids, glucose-6-phosphatase values decreased to 35.3% and 58.7% of normal activity respectively, while monoamine oxidase levels returned to normal. However, only linolenic acid was effective in restoring 5′-mononucleotidase activities to normal while linoleic acid produced no change from the deficient values. The results would indicate that linolenic acid may have a biochemical function distinct from linoleic acid in 5′-mononucleotidase metabolism.
Article
— Three dietary levels of essential fatty acids, 30, 0-75 and 007 calorie-%, with a linoleic: linolenic acid ratio of 4:1, were fed to rats for two generations. In the third generation the weight of the cerebrum and the concentration of its lipids and the fatty acid composition of phosphoglycerides were determined from term to 120 days of age. The cerebral weights and the concentrations of phospholipids, cholesterol and cerebrosides differed only slightly between the three dietary groups. The accretion of fatty acids of the linoleic acid series was independent of the dietary essential fatty acid level while the accretion of fatty acids of the linolenic acid series was markedly reduced in the groups with low essential fatty acid supply. The sum of the total polyunsaturated fatty acids in ethanolamine phosphoglycerides differed only slightly between the groups. The proportion of the major polyunsaturated fatty acid of the linoleic acid series was equal between the groups while that of 22:6 (n-3) was much lower in the groups fed 007 calorie % essential fatty acids. In these latter groups the relative concentrations of 22:5 (n-6), 20:3 (n-9) and 22:3 (n-9) were increased. The differences in the fatty acid composition were dependent on the age of the rats. They were largest in newborn rats and diminished with age after weaning.
Article
Transient photodichroism in the frog retina reveals that rhodopsin has a relaxation time of 20 µs. The site rhodopsin occupies in the membrane must therefore be highly fluid. This suggests rhodopsin may be a diffusional carrier.
Article
Dichroism can be photoinduced in a frog retina once it has been fixed with glutaraldehyde. This dichroism is absent in the normal retina because rhodopsin is free to undergo rotational Brownian motion.
Article
Autoradiographic experiments demonstrate that the renewal process of the rod photoreceptors in the rat retina is altered during essential fatty acid deficiency. After the administration of tritiated amino acids, animals raised on a fat-free ration show no evidence of disc formation, while those raised on a normnal ration show disc formation and renewal. The latter process is apparently dependent upon the availability of linoleic or linolenic (or both) fatty acids.
Article
The fatty acid composition of rat photoreceptor membranes was altered by dietary manipulation. A functional alteration was also observed in the component of the electroretinogram which is generated by the photoreceptors. A membrane fatty acid, docosahexaenoic acid, appears to be involved in the transduction process of visual excitation.
Article
—Fatty acids typical of grey matter lipids (C20:4 and C22:6) and of myelin lipids (C20:1 and C24:1) were estimated in developing rat brains. The polyenoic fatty acids (C20:4 and C22:6) are synthesized from the essential fatty acids (C18:2 and C18:3). The results showed that more than 50 per cent of the adult content of the brain polyenoic acids were laid down by day 15. In contrast, the fatty acids characteristic of myelin lipids did not appear in significant quantities until after this time. These findings distinguish biochemically the different periods of brain development associated firstly with cell division (formation of neurons and glial cells) and secondly with myelination. It is of special interest that the period of cell proliferation is accompanied by the appearance in brain lipids of long-chain polyenoic acids derived from the essential fatty acids.
Article
Rats raised for 10 weeks on fat-free or lab chow diets were sacrificed, their retinas removed, and rod outer segments prepared for lipid analysis. No differences were found in the phospholipid composition and only small differences were observed in the fatty acid distribution in the phospholipids of these photoreceptor membranes. The usual indicator of essential fatty acid deficiency, 20:3ω9, accumulated in all of the tissues examined except the retina and the photoreceptor membranes. Since rat photoreceptor membranes are completely renewed every 9 days the retina must have a mechanism for conserving its abundant supply of ω3 polyunsaturates.
Article
To determine the effect of long-term deprivation of linolenate on growth and reproduction, female weanling Long-Evans rats were raised on a diet containing 1.25% methyl linoleate (2.7% of calories) as the only source of fatty acids. Control rats were given 1.0% methyl linoleate and 0.25% methyl lino lenate. Rats in both groups were fertile and gave birth to normal litters. Pups were raised on the diet containing only linoleate, and both males and females were fertile and produced normal pups. Supplementation of third-generation de ficient rats at weaning with the control diet containing linolenate and linoleate did not produce any change in growth compared with littermates continued on the diet that contained only linoleate. Thus, linolenic acid does not appear to be essential for growth or reproduction in rats. Fatty acids of various tissues were analyzed and were found to reflect the compositions of their dietary precursors, as expected; that is, in rats given no dietary w-3 fatty acids, tissue levels of w-3 fatty acids were very low or undetectable. These, 22:5»3and 22:6»3,were re placed by 22:4«6and 22:5*6. J. Nutr. 70Í:937-946, 1971.