Omega-3 Long-chain Polyunsaturated Fatty Acids Research Articles

Creation of a database to assess effects of omega-3, omega-6 and total polyunsaturated fats on health: methodology for a set of systematic reviews

ObjectiveTo create a database of long-term randomised controlled trials (RCTs) comparing higher with lower omega-3, omega-6 or total polyunsaturated fatty acid (PUFA), regardless of reported outcomes, and to develop methods...

Plasma oxylipins respond in a linear dose-response manner with increased intake of EPA and DHA: results from a randomized controlled trial in healthy humans

The health effects of long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) are partly mediated by their oxidized metabolites, i.e., eicosanoids and other oxylipins. Some intervention studies have demonstrated that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increase systemic concentrations of n-3 PUFA-derived oxylipins and moderately decrease arachidonic acid-derived oxylipins. There is no information on the dose-response of oxylipin concentrations after n-3 PUFA intake. The aim of this study was to quantify oxylipins in human plasma samples from an intervention study in which participants were randomly assigned to different daily intakes of EPA and DHA for 12 mo. Healthy adult men and women with low habitual fish consumption (n=121) were randomly assigned to receive capsules providing doses of n-3 PUFAs reflecting 3 patterns of consumption of oily fish [1, 2, or 4 portions/wk with 3.27 g EPA+DHA (1:1.2, wt:wt) per portion] or placebo. Oxylipins were quantified in plasma after 3 and 12 mo. Relative and absolute changes of individual oxylipins were calculated and concentrations were correlated with the dose and the content of EPA and DHA in blood lipid pools. Seventy-three oxylipins, mostly hydroxy-, dihydroxy-, and epoxy-PUFAs, were quantified in the plasma samples. After 3 and 12 mo a linear increase with dose was observed for all EPA- and DHA-derived oxylipins. Cytochrome-P450-derived anti-inflammatory and cardioprotective epoxy-PUFAs increased linearly with n-3 PUFA dose and showed low interindividual variance (r2>0.95). Similarly, 5, 12-, and 15-lipoxygenase-derived hydroxy-PUFAs as well as those formed autoxidatively increased linearly. These include the precursors of so-called specialized pro-resolving lipid mediators (SPMs), e.g., 17-hydroxy-DHA and 18-hydroxy-EPA. Plasma concentrations of biologically active oxylipins derived from n-3 PUFAs, including epoxy-PUFAs and SPM-precursors, increase linearly with elevated intake of EPA and DHA. Interindividual differences in resulting plasma concentrations are low. This trial was registered at controlled-trials.com as ISRCTN48398526.

Methyl-end desaturases with ∆12 and ω3 regioselectivities enable the de novo PUFA biosynthesis in the cephalopod Octopus vulgaris

The interest in understanding the capacity of aquatic invertebrates to biosynthesise omega-3 (ω3) long-chain (≥C20) polyunsaturated fatty acids (LC-PUFA) has increased in recent years. Using the common octopus Octopus vulgaris as a model species, we previously characterised a ∆5 desaturase and two elongases (i.e. Elovl2/5 and Elovl4) involved in the biosynthesis of LC-PUFA in molluscs. The aim of this study was to characterise both molecularly and functionally, two methyl-end (or ωx) desaturases that have been long regarded to be absent in most animals. O. vulgaris possess two ωx desaturase genes encoding enzymes with ∆12 and ω3 regioselectivities enabling the de novo biosynthesis of the C18 PUFA 18:2ω6 (LA, linoleic acid) and 18:3ω3 (ALA, α-linolenic acid), generally regarded as dietary essential for animals. The O. vulgaris ∆12 desaturase (“ωx2”) mediates the conversion of 18:1ω9 (oleic acid) into LA, and subsequently, the ω3 desaturase (“ωx1”) catalyses the ∆15 desaturation from LA to ALA. Additionally, the O. vulgaris ω3 desaturase has ∆17 capacity towards a variety of C20 ω6 PUFA that are converted to their ω3 PUFA products. Particularly relevant was the affinity of the ω3 desaturase towards 20:4ω6 (ARA, arachidonic acid) to produce 20:5ω3 (EPA, eicosapentaenoic acid), as supported by yeast heterologous expression, and enzymatic activity exhibited in vivo when paralarvae were incubated in the presence of [1-14C]20:4ω6. These results confirmed that several routes enabling EPA biosynthesis are operative in O. vulgaris whereas ARA and docosahexaenoic acid (DHA, 22:6ω3) should be considered essential fatty acids since endogenous production appears to be limited.

Association between plasma phospholipid omega-3 polyunsaturated fatty acids and type 2 diabetes is sex dependent: The Hunter Community Study

Chronic inflammation drives the development of insulin resistance and type 2 diabetes. Long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) eicosapentaenoic acid (EPA, c20:5n-3) and docosahexaenoic acid (DHA, c22:6n-3) may protect against type 2 diabetes development. The aim of this current study is to determine whether LCn-3PUFA status is associated with type 2 diabetes in the Hunter Community Study. Men and women aged 55-85 years were randomly selected from the electoral roll and invited to participate. Participants were included in the current study if they had plasma phospholipid fatty acid composition data available and diabetes status could be determined. LCn-3PUFA status was determined by fatty acid composition of plasma phospholipids (EPA+DHA, %,w/w). Diabetes was determined according to World Health Organisation criteria. Insulin was measured in n=251 participants and HOMA-IR calculated. In total, n=2092 (diabetes: n=249) participants were included. After adjusting for confounders of diabetes, LCn-3PUFA status was inversely associated with diabetes in overweight/obese females (OR [95%CI]: 0.90 [0.80, 1.00], p=0.045) but not males (p-interactionsex=0.041). Overweight/obese females with diabetes had significantly lower levels of DHA than those without diabetes (mean difference [95%CI]:-0.53 [-0.87,-0.20], p=0.002), with no difference in EPA. LCn-3PUFA was inversely associated with HOMA-IR (r=-0.175, p=0.005). This study provides further evidence of a sex-dependent association between LCn-3PUFA and type 2 diabetes. Causal pathways between LCn-3PUFA and type 2 diabetes merits delineation.

Two Co-Expression Strategies for Eicosapentaenoic Acid Production in Mortierella alpina

The omega-3 long-chain Polyunsaturated Fatty Acid (PUFA) Eicosapentaenoic Acid (EPA) has beneficial effects on human health, leading to its use in health products and foods. The oleaginous microorganism Mortierella alpina has been used in the industrial production of Arachidonic Acid (AA). The omega-3 desaturase oPpFADS17 is a key enzyme in the bioconversion of AA to EPA from Phytophthora parasitica and Glucose-6-Phosphate Dehydrogenase (G6PD2) is a critical enzyme that provide reducing power NADPH for lipid biosynthesis. In this study, we used a double expression cassette and 2A peptide strategies to co-express the these two critical enzymes. Subsequently, we investigated the effects of these strategies on total lipid and EPA accumulation. The recombination strains generated using the above-described strategies exhibited no differences in cell growth, compared with the control strain. Recombination strains generated using the double expression cassette exhibited an increase in total lipids to 43% of the cell dry weight, but did not accumulate EPA. Recombination strains generated using the 2A peptide strategy exhibited increased EPA accumulation, such that this PUFA accounted for 30% of the total lipid content. These co-expression strategies provide the improvements of multi-gene modification in PUFA accumulation in M. alpina.

Omega-3 polyunsaturated fatty acid intake norms and preterm birth rate: a cross-sectional analysis of 184 countries

BackgroundThe preponderance of evidence now indicates that elevated long-chain omega-3 polyunsaturated fatty acid (LC omega-3 PUFA) intake is often associated with reduced risk of preterm birth (PTB). This conclusion is...

Omega-3 Fatty Acid Addition During Pregnancy

(Abstracted from Cochrane Database Syst Rev 2018;11:CD003402) Preterm birth is a leading cause of disability or death in the first 5 years of life. Higher intake of foods containing omega-3 long-chain polyunsaturated fatty acids (LCPUFAs), such as fish, during pregnancy has been associated with longer gestations and improved perinatal outcomes.

Enhancing Omega-3 Long-Chain Polyunsaturated Fatty Acid Content of Dairy-Derived Foods for Human Consumption.

Omega-3 polyunsaturated fatty acids (n-3 PUFA) are termed essential fatty acids because they cannot be synthesized de novo by humans due to the lack of delta-12 and delta-15 desaturase enzymes and must therefore be acquired from the diet. n-3 PUFA include α-linolenic acid (ALA, 18:3n-3), eicosapentaenoic (EPA, 20:5n-3), docosahexaenoic (DHA, 22:6n-3), and the less recognized docosapentaenoic acid (DPA, 22:5n-3). The three long-chain (≥C20) n-3 PUFA (n-3 LC-PUFA), EPA, DHA, and DPA play an important role in human health by reducing the risk of chronic diseases. Up to the present time, seafood, and in particular, fish oil-derived products, have been the richest sources of n-3 LC-PUFA. The human diet generally contains insufficient amounts of these essential FA due largely to the low consumption of seafood. This issue provides opportunities to enrich the content of n-3 PUFA in other common food groups. Milk and milk products have traditionally been a major component of human diets, but are also among some of the poorest sources of n-3 PUFA. Consideration of the high consumption of milk and its processed products worldwide and the human health benefits has led to a large number of studies targeting the enhancement of n-3 PUFA content in dairy products. The main objective of this review was to evaluate the major strategies that have been employed to enhance n-3 PUFA content in dairy products and to unravel potential knowledge gaps for further research on this topic. Nutritional manipulation to date has been the main approach for altering milk fatty acids (FA) in ruminants. However, the main challenge is ruminal biohydrogenation in which dietary PUFA are hydrogenated into monounsaturated FA and/or ultimately, saturated FA, due to rumen microbial activities. The inclusion of oil seed and vegetable oil in dairy animal diets significantly elevates ALA content, while the addition of rumen-protected marine-derived supplements is the most effective way to increase the concentration of EPA, DHA, and DPA in dairy products. In our view, the mechanisms of n-3 LC-PUFA biosynthesis pathway from ALA and the biohydrogenation of individual n-3 LC-PUFA in ruminants need to be better elucidated. Identified knowledge gaps regarding the activities of candidate genes regulating the concentrations of n-3 PUFA and the responses of ruminants to specific lipid supplementation regimes are also critical to a greater understanding of nutrition-genetics interactions driving lipid metabolism.

Prenatal Omega-6:Omega-3 Ratio and Attention Deficit and Hyperactivity Disorder Symptoms

To evaluate whether higher omega-6:omega-3 (n-6:n-3) long-chain polyunsaturated fatty acid ratio in cord plasma is associated with more symptoms of attention deficit and hyperactivity disorder (ADHD) at 4 and 7years of age. This study was based on a population-based birth cohort in Spain. N-6 arachidonic acid and n-3 eicosapentaenoic and docosahexaenoic acid concentrations were measured in cord plasma. At 4years old, ADHD symptoms were reported by teachers through the ADHD Diagnostic and Statistical Manual of Mental Disorders, 4th ed checklist (n=580). At 7years old, ADHD symptoms were reported by parents through the Conners' Rating Scale-Revised (short form; n=642). The ADHD variable was treated as continuous (score) and as dichotomous (symptom diagnostic criteria). Child and family general characteristics were prospectively collected through questionnaires. We applied pooled zero-inflated negative binomial and logistic regressions adjusted for covariates. A higher omega-6:omega-3 long-chain polyunsaturated fatty acid ratio in cord plasma was associated with a higher ADHD index (incidence rate ratio, 1.13; 95% CI, 1.03, 1.23) at 7years old. The association was not observed at 4years old (incidence rate ratio, 1.04; 95% CI, 0.92-1.18). No associations were found using ADHD symptom diagnostic criteria. High prenatal omega-6:omega-3 long-chain polyunsaturated fatty acid ratio preceded the appearance of subclinical ADHD symptoms during mid-childhood. Our findings suggest that maternal diet during pregnancy may modulate the risk to develop long-term ADHD symptoms in the offspring.

Dietary omega-3 and antioxidants improve long-chain omega-3 and lipid oxidation of broiler meat

BackgroundThis study aimed to investigate the possibility of producing broiler meat rich in long-chain n-3 polyunsaturated fatty acids especially eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3) with preventing lipid oxidation of the produced meat by supplementing the diets with linseed oil or fish oil along with vitamin E (Vit. E) or sweet chestnut tannins (SCT) as antioxidants. A total of 144 1-day-old Cobb broiler chicks were divided into six treatments with three replicates, eight chicks each. The treatments were basal diets containing 2 g linseed oil/100 g (T1), 2 g linseed oil/100 g + 200 mg Vit. E/kg (T2) and 2 g linseed oil/100 g + 2 g SCT/kg (T3), 2 g fish oil/100 g (T4), 2 g fish oil/100 g + 200 mg Vit. E/kg (T5), and 2 g fish oil/100 g + 2 g SCT/kg (T6) for 5 weeks. Fatty acid composition, thiobarbituric acid (TBA), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity were determined.ResultsDietary 2 g fish oil/100 g elevated (P ≤ 0.001) long-chain omega-3 polyunsaturated fatty acids in broiler meat mainly EPA and DHA. At the same time, dietary fish oil resulted in a significant decrease (P ≤ 0.001) in α-linolenic acid in broiler meat (6%). However, total omega-3 fatty acids in meat were higher (P ≤ 0.001) with dietary fish oil than with dietary linseed oil. The ratio of n-6:n-3 PUFA was decreased (P ≤ 0.001) in the meat of broilers fed diets containing 2 g fish oil/100 g compared with broilers fed diets containing 2 g linseed oil/100 g. The two sources of antioxidant decreased (P ≤ 0.05) TBA value and increased (P ≤ 0.05) the DPPH radical scavenging activity in broiler meat compared to the diet without antioxidant. No significant differences observed between chicks fed 2 g SCT/kg or 200 mg Vit. E/kg on TBA and DPPH radical scavenging activity.ConclusionsIt is concluded that inclusion of 2 g fish oil/100 g in broiler diets elevated levels of long-chain omega-3 PUFA mainly EPA and DHA, but decreased n-6:n-3 ratio. Moreover, the addition of 2 g SCT/kg diet or 200 mg Vit. E/kg diet as antioxidant sources inhibited lipid oxidation and enhanced antioxidant activity value in broiler meat, and each of them had the same effect.

Boundary Lipids of the Nicotinic Acetylcholine Receptor in Quasi-Native Membranes

The nicotinic acetylcholine receptor (nAChR) is a neurotransmitter receptor and pentameric ligand gated ion channel (pLGIC) critical for signaling across synapses, including the neuromuscular junction. In reconstituted membranes, the nAChR function depends heavily on cholesterol, leading to the hypothesis that nAChR will partition into cholesterol-enriched liquid-ordered domains ("rafts”). Native nAChR membranes are rich in lipids with saturated fatty acid (like palmitic acid) or polyunsaturated fatty acid (PUFA) acyl chains (like docosahexaenoic acid (DHA)). Using coarse-grained molecular dynamics simulations we characterized preferential lipid interactions and partitioning behavior of nAChR in binary membranes (cholesterol and lipids with two palmitic acid acyl chains) ternary membranes (cholesterol, a lipid with two palmitic acid acyl chains, and lipids with either two chains composed of the long-chain omega-3 PUFA DHA or of the omega-6 PUFA linoleic acid). We quantify occupation of non-annular and annular regions by cholesterol and saturated and polyunsaturated lipids. In the absence of PUFAs, cholesterol is enriched in the nAChR annulus in a concentration-dependent manner. Cholesterol is also distributed throughout the non-annular (embedded) sites, while palmatic acyl chains persistently occupy only one interface between the beta and alpha subunits. When lipids containing long-chain PUFA acyl chains are introduced, they displace cholesterol from two additional interfaces. Contrary to expectations, in domain-forming membranes containing PUFAs, the nAChR is observed to consistently partition into PUFA-rich, cholesterol-poor domains. Saturated lipids with either phosphatidylcholine and phosphatidylethanolamine head groups are significantly depleted in such systems, although the extent of depletion is reduced for phosphatidylethanolamine. While nAChR consistently partitions into the cholesterol poor domain, alpha-gamma and delta-beta faces interact more than other faces with the cholesterol-rich domains. We extend this approach to more complex membranes of interest, including more realistic synaptic membranes and the Xenopus oocyte membranes used for electrophysiology.

A Genetic Score of Predisposition to Low-Grade Inflammation Associated with Obesity May Contribute to Discern Population at Risk for Metabolic Syndrome.

Omega-3 rich diets have been shown to improve inflammatory status. However, in an ex vivo system of human blood cells, the efficacy of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) modulating lipid metabolism and cytokine response is attenuated in overweight subjects and shows high inter-individual variability. This suggests that obesity may be exerting a synergistic effect with genetic background disturbing the anti-inflammatory potential of omega-3 long-chain polyunsaturated fatty acids (PUFA). In the present work, a genetic score aiming to explore the risk associated to low grade inflammation and obesity (LGI-Ob) has been elaborated and assessed as a tool to contribute to discern population at risk for metabolic syndrome. Pro-inflammatory gene expression and cytokine production as a response to omega-3 were associated with LGI-Ob score; and lower anti-inflammatory effect of PUFA was observed in subjects with a high genetic score. Furthermore, overweight/obese individuals showed positive correlation of both plasma C-Reactive Protein and triglyceride/HDLc-index with LGI-Ob; and high LGI-Ob score was associated with greater hypertension (p = 0.047), Type 2 diabetes (p = 0.026), and metabolic risk (p = 0.021). The study shows that genetic variation can influence inflammation and omega-3 response, and that the LGI-Ob score could be a useful tool to classify subjects at inflammatory risk and more prone to suffer metabolic syndrome and associated metabolic disturbances.

Curcumin and/or omega-3 polyunsaturated fatty acids supplementation reduces insulin resistance and blood lipids in individuals with high risk of type 2 diabetes: a randomised controlled trial

BackgroundLowering insulin resistance and dyslipidaemia may not only enhance glycaemic control but also preserve the β-cell function, reducing the overall risk of developing type 2 diabetes (T2D). The current study was aimed to evaluate the effects of curcumin and/or long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) supplementation on glycaemic control and blood lipid levels in individuals at high risk of developing T2D.MethodsThis was a 2 × 2 factorial, randomised, double-blinded, placebo-controlled study. Participants were allocated to either double placebo (PL) or curcumin plus placebo matching for LCn-3PUFA (CC), or LCn-3PUFA plus placebo matching for curcumin (FO), or curcumin plus LCn-3PUFA (CC-FO) for twelve weeks. Primary outcome of the trial was glycaemic indices (HbA1C, fasting glucose and insulin). Insulin resistance and sensitivity is measured using homeostatic model assessment model.ResultsA total of sixty-four participants (PL, n = 16; CC, n = 15; FO, n = 17, CC-FO, n = 16) were included in the final analysis. Post-intervention, HbA1c and fasting glucose remained unchanged across all the groups. Insulin sensitivity was significantly improved in the CC supplemented group (32.7 ± 10.3%) compared to PL (P = 0.009). FO and CC-FO tended to improve insulin sensitivity by 14.6 ± 8.5% and 8.8 ± 7.7% respectively, but the difference did not reach significance. Triglyceride levels were further increased in the PL (26.9 ± 7.4%), however, CC and CC-FO supplementation reduced the triglycerides, FO resulted in the greatest reduction in triglycerides (− 16.4 ± 4.5%, P < 0.001).ConclusionReduction in insulin resistance and triglycerides by curcumin and LCn-3PUFA appears to be attractive strategies for lowering the risk of developing T2D. However, this study failed to demonstrate complimentary benefits of curcumin and LCn-3PUFA on glycaemic control.Trail registrationACTRN12615000559516.

Long-Chain Polyunsaturated Fatty Acids in the Green Microalga Lobosphaera incisa Contribute to Tolerance to Abiotic Stresses.

Lobosphaera incisa is a green microalga that accumulates high levels of the valuable omega-6 long-chain polyunsaturated fatty acids (LC-PUFA) arachidonic acid (ARA, 20:4n-6) in triacylglycerols (TAG) under nitrogen (N) starvation. LC-PUFA accumulation is a rare trait in photosynthetic microalgae with insufficiently understood physiological significance. In this study, RNAi was attempted, for the first time in L. incisa, to produce knockdown lines for the Δ5 desaturase gene. Two lines, termed modified lines, which were isolated during screening for transgenic events, demonstrated alterations in their LC-PUFA profile, ARA-biosynthesis gene expression and lipid class distribution. In line M5-78, which appeared to carry a mutation in the Δ6 elongase gene, LC-PUFA were substituted by 18:3n-6 in all glycerolipids. Line M2-35, for which the exact genetic background has not been established, displayed a dramatic reduction in 20:4n-6, concomitant with an augmented proportion of 18:1n-9, in particular in the extraplastidial membrane lipids and TAG. The physiological responses of the modified lines to stressful conditions were compared with the wild type and the Δ5 desaturase mutant. In the N-replete cells of modified lines, the frequency of lipid droplets was reduced, while a number of starch grains increased, suggesting altered partitioning of assimilated carbon into reserve products. Furthermore, both lines exhibited reduced ability to accumulate TAG under N deprivation and recover from N starvation. Both lines demonstrated lower photosynthetic pigment contents, impairments in photosynthesis under a range of stressful conditions, and less efficient functioning of photoprotection under optimal conditions. Possible implications of fatty acids modifications in the stress response of L. incisa are addressed.

Omega-3 Long-Chain Polyunsaturated Fatty Acids, EPA and DHA: Bridging the Gap between Supply and Demand.

The omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic (DHA, 22:6n-3) acids, are well accepted as being essential components of a healthy, balanced diet, having beneficial effects on development and in mitigating a range of pathological conditions. However, their global supply from all the traditional sources of these nutrients is insufficient to satisfy human nutritional requirements. For two decades there has been considerable research carried out into all possible alternatives to the main sources of n-3 LC-PUFA, marine fish oil and fishmeal, driven largely by the aquaculture sector, as both the major user and provider of EPA and DHA. In the last few years these efforts have focused increasingly on the development of entirely new supplies of n-3 LC-PUFA produced de novo. Recently, this has resulted in various new sources of EPA and/or DHA that are already available or likely to available in the near future. In this short review, we briefly summaries the current gap between supply and demand of EPA and DHA for human requirements, the role of aquaculture in providing n-3 LC-PUFA to human consumers, the range of potential novel sources, and suggest how these new products could be used effectively. We conclude that all the new sources have potentially important roles to play in increasing the supply of n-3 LC-PUFA so that they are available more widely and in higher concentrations providing more options and opportunities for human consumers to obtain sufficient EPA and DHA to support more healthy, balanced diets.

Effect of Eicosapentaenoic Acid Supplementation on Paraoxonase 2 Gene Expression in Patients with Type 2 Diabetes Mellitus: a Randomized Double-blind Clinical Trial.

Type 2 diabetes mellitus (T2DM) is recognized as one of the most prevalent metabolic diseases, and it is mostly associated with oxidative stress, atherosclerosis and dyslipidemia. Paraoxonase 2 (PON2) due to its antioxidant properties may play a role in the atherosclerosis development. Although long-chain omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) have been shown to reduce the risk of cardiovascular disease, the exact mechanism of action is still unknown. Our goal in this study was to determine the effect of EPA administration on gene expression of PON2 in patients with T2DM. Present study was a randomized, controlled double-blind trial. Thirty-six patients with T2DM were randomly allocated to receive 2 g/day EPA (n = 18) or placebo (n = 18) for 8 weeks. There were no significant differences between 2 groups concerning demographic or biochemical variables, and dietary intakes as well (p > 0.05). However, patients received EPA showed a significant increase in the gene expression of PON2 compared with placebo group (p = 0.027). In addition, high-density lipoprotein cholesterol increased and fasting blood sugar decreased significantly after EPA supplementation compared with control group. Taken together, supplementation with 2 g/day EPA could be atheroprotective via the upregulation of PON2 in patients with T2DM.Trial RegistrationClinicalTrials.gov Identifier: NCT03258840

Functional mode of action of ASP5736, a selective 5-HT5A receptor antagonist for treatment of cognitive dysfunction in schizophrenia

Docosahexaenoic acid (DHA) is an omega-3 long-chain polyunsaturated fatty acid that accumulates in neural tissues during intrauterine development, particularly in the frontal lobes of the brain. The frontal lobes are responsible for a suite of cognitive abilities referred to as ‘executive functions.’ Executive function skills include attention, working memory (the ability to mentally manipulation information), and inhibitory control (the ability to control or supress inappropriate actions).In this chapter, we briefly review the development of the human brain and the accumulation of DHA in the brain. The main focus is on summarizing the evidence from randomized controlled trials that have supplemented pregnant women with DHA and measured the effects on children’s executive functions. We provide details of the different assessments of executive function that have been used in trials, and summarize the evidence base with respect to dose of DHA used in trials and age when executive functions are measured. We conclude with some recommendations for future trials in this area.

Omega-3 Uzun Zincirli Çoklu Doymamış Yağ Asitleri ve Fenilketonüri

Beyin, retina ve diğer sinir dokuları uzun zincirli çoklu doymamış yağ asitlerinden (UZÇDYA) zengindir. Birçok klinik ve epidemiyolojik çalışma ile omega-3 UZÇDYA’ların çocukluk çağındaki nöral gelişim üzerine olumlu etkileri olduğu kanıtlanmıştır. Uzun zincirli ÇDYA’lar, diyetle alımları yeterli olduğu sürece temel elzem yağ asitlerinden endojen olarak sentezlenebilirler. Aynı zamanda, et, balık, yumurta, karaciğer ve süt ürünleri gibi proteinden zengin besinler eikosapentaenoik asit (EPA) ve dokosaheksaenoik asit (DHA) gibi UZÇDYA’ların en belirgin diyetsel kaynaklarıdır. Bununla birlikte, klasik fenilketonürili (FKÜ) hastalar yüksek plazma fenilalanin konsantrasyonları ve nörolojik hasarı önlemek için diyet protein alımında sıkı ve ömür boyu süren bir sınırlamaya ihtiyaç duyarlar. Bu katı metabolik kontrol sadece düşük miktarda vitamin ve mineral sağlamakla kalmaz, genellikle doymuş yağ asitleri ve ÇDYA’ların da düşük miktarda alınmasına neden olur. Bu nedenle, FKÜ’lü hastalar sağlıklı kontrollerle karşılaştırıldığında UZÇDYA alımları daha az olmakta ve daha düşük plazma ve eritrosit UZÇDYA konsantrasyonlarına sahip olmaktadırlar. Bebeklik ve çocukluk döneminde, UZÇDYA’lar normal nörogelişim için önemlidir. Yetersizliği, okul öncesi ve okul çağındaki FKÜ’lü çocuklarda erken dönemde saptanabilen merkezi sinir sistemi işlev bozukluklarına katkıda bulunabilir. Ayrıca, UZÇDYA yetersizliğinin kronik nörolojik, inflamatuvar ve metabolik bozukluklara neden olabileceği de ileri sürülmektedir. Diğer taraftan, randomize kontrollü çalışmalardan elde edilen veriler, FKÜ’lü hastalardaki UZÇDYA durumunun diyet takviyesi ile iyileştirilebileceğini önermektedir. Bu derleme yazıda, fenilalaninden kısıtlı diyetler ile UZÇDYA arasındaki ilişki incelenmiş ve FKÜ’lü hastalar için UZÇDYA’ların önemi ele alınmıştır.

383 Feeding dogs and cats with renal disease: What do we really know.

Dietary management of renal disease involves restricting protein, phosphorus, and sodium in the diet while enhancing the levels of water-soluble vitamins and the long-chain omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA). Recent evidence supports the avoidance of high phosphorus intake in older dogs and cats, even before overt biochemical or clinical signs of renal disease are present. Animals with decreased tubular function as indicated by loss of urine concentration, elevated serum symmetric dimethylarginine (SDMA), and evidence of structural changes on imaging studies, with or without elevations in creatinine, should be fed a diet with a dietary phosphorus level at or below the National Research Council (NRC) minimum requirement for an adult dog or cat. For animals with glomerular disease, loss of plasma proteins (such as albumin) into the urine can result in progressive renal tubular damage. The degree of proteinuria is exacerbated with increased protein intake. The dietary treatment for this form of renal disease involves a reduction of dietary protein intake to the NRC recommended minimum, which will help decrease glomerular capillary pressure and subsequently lessen proteinuria. Dogs can become hyperkalemic as a function of progressive renal disease or secondary to medications, such as the ACE inhibitors enalapril and benazapril, and potassium restriction may be required to prevent potentially fatal hyperkalemic cardiac arrhythmias. Conversely, cats with renal disease often have enhanced loss of potassium through their urine and coupled with poor overall dietary intake may require potassium supplementation as clinical hypokalemia can result in constipation and generalized muscle weakness. Imbalance in orexigenic compounds, such as ghrelin, and anorexigenic compounds, such as cholecystokinin, can also occur with advanced uremia resulting in dysregulation of food intake and progressive cachexia. Appetite stimulants or placement of a feeding tube may be required to deliver optimal nutritional support with advanced renal failure.

Simultaneous extraction and fractionation of omega-3 acylglycerols and glycolipids from wet microalgal biomass of Nannochloropsis gaditana using pressurized liquids

Microalgae are primary producers of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in marine environment and so they are considered promising alternative sources of omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs). Nannochloropsis gaditana is an oleaginous cultivated microalga with an important content of triglycerides and polar lipids which include interesting EPA amounts. In this work, new methods using pressurized liquids for simultaneous extraction and fractionation of neutral and polar lipids from wet microalgal biomass are proposed. Pressurized liquid extraction (PLE) using different solvents, combined or not with pre-treatment of the alga with enzymes, allows one to enrich and fractionate neutral and polar lipids such as triacylglycerols, diacylglycerols, monoacylglycerols, free fatty acids and glycolipids. The use of enzymatic pre-treatment did not show a significant increase in the lipid yield, though a different fractionation of the microalgal lipids was achieved. PLE with a single solvent (hexane at 120 °C) rendered a lipid yield of 17.6%, slightly higher than the traditional Folch method (16.9%), but with a less-toxic solvent and faster extraction technique. In addition, PLE with hexane attained a high triacylglycerols fraction (17.2% ± 3.0). The optimal four-step sequential method developed using pressurized liquids reached a good fractionation characterized by a high content of glycolipids (29.2% ± 2.0) and monoacylglycerols (17.3% ± 1.9), with a lipid recovery of 14.0% ± 1.3 for the original biomass. The analysis by GC/MS of fractions obtained with each method and solvent combination, showed a different composition in fatty acids of fractionated neutral and polar lipid species, especially in saturated and omega-3 fatty acids. Therefore, the proposed fast PLE methods allow the simultaneous extraction and fractionation of the neutral and polar lipids of Nannochloropsis gaditana and produce enriched EPA fractions (up to 53%).