Showing papers on "Docosahexaenoic acid published in 2019"

Effects of Omega-3 Fatty Acids on Immune Cells.

Abstract: Alterations on the immune system caused by omega-3 fatty acids have been described for 30 years. This family of polyunsaturated fatty acids exerts major alterations on the activation of cells from both the innate and the adaptive immune system, although the mechanisms for such regulation are diverse. First, as a constitutive part of the cellular membrane, omega-3 fatty acids can regulate cellular membrane properties, such as membrane fluidity or complex assembly in lipid rafts. In recent years, however, a new role for omega-3 fatty acids and their derivatives as signaling molecules has emerged. In this review, we describe the latest findings describing the effects of omega-3 fatty acids on different cells from the immune system and their possible molecular mechanisms.

Omega-3 Fatty Acids for the Management of Hypertriglyceridemia: A Science Advisory From the American Heart Association

Abstract: Hypertriglyceridemia (triglycerides 200–499 mg/dL) is relatively common in the United States, whereas more severe triglyceride elevations (very high triglycerides, ≥500 mg/dL) are far less frequent...

Efficacy of omega-3 PUFAs in depression: A meta-analysis.

Abstract: We conducted this meta-analysis of double-blind randomized placebo-controlled trials to estimate the efficacy of omega-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), in the improvement of depression. We applied a systematic bibliographic search in PubMed and EMBASE for articles published prior to 20 December 2017. This meta-analysis was performed using RevMan 5.3 and R 3.4.3, and means and standard deviations were calculated in fixed- or random-effects models based on the results of the Q-test. A sensitivity analysis was also conducted to evaluate the stability of the results, and publication bias was evaluated by a funnel plot and Egger’s linear regression analysis. Our search resulted in 180 articles; we analyzed 26 studies, which included 2160 participants. The meta-analysis showed an overall beneficial effect of omega-3 polyunsaturated fatty acids on depression symptoms (SMD = −0.28, P = 0.004). Compared with placebo, EPA-pure (=100% EPA) and EPA-major formulations (≥60% EPA) demonstrated clinical benefits with an EPA dosage ≤1 g/d (SMD = −0.50, P = 0.003, and SMD = −1.03, P = 0.03, respectively), whereas DHA-pure and DHA-major formulations did not exhibit such benefits. Current evidence supports the finding that omega-3 PUFAs with EPA ≥ 60% at a dosage of ≤1 g/d would have beneficial effects on depression. Further studies are warranted to examine supplementation with omega-3 PUFAs for specific subgroups of subjects with inflammation, severity of depression, and the dose response for both EPA and DHA supplementation.

Lipid Accumulation and Chronic Kidney Disease

Abstract: Obesity and hyperlipidemia are the most prevalent independent risk factors of chronic kidney disease (CKD), suggesting that lipid accumulation in the renal parenchyma is detrimental to renal function. Non-esterified fatty acids (also known as free fatty acids, FFA) are especially harmful to the kidneys. A concerted, increased FFA uptake due to high fat diets, overexpression of fatty acid uptake systems such as the CD36 scavenger receptor and the fatty acid transport proteins, and a reduced β-oxidation rate underlie the intracellular lipid accumulation in non-adipose tissues. FFAs in excess can damage podocytes, proximal tubular epithelial cells and the tubulointerstitial tissue through various mechanisms, in particular by boosting the production of reactive oxygen species (ROS) and lipid peroxidation, promoting mitochondrial damage and tissue inflammation, which result in glomerular and tubular lesions. Not all lipids are bad for the kidneys: polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) seem to help lag the progression of chronic kidney disease (CKD). Lifestyle interventions, especially dietary adjustments, and lipid-lowering drugs can contribute to improve the clinical outcome of patients with CKD.

Fatty Acid Profiles and Production in Marine Phytoplankton

Abstract: Microalgae are the primary producers of carbon in marine ecosystems, fixing carbon and subsequently generating various biomolecules such as carbohydrates, proteins and lipids. Most importantly, microalgae are the generators and main suppliers of ω3 polyunsaturated fatty acids (ω3PUFA) in the marine ecosystem, which have a fundamental importance for the functioning and quality of the whole marine food web. A meta-analysis of over 160 fatty acid profiles of 7 marine phytoplankton phyla reveals not only a phyla-specific, but also a highly class-specific PUFA production of marine phytoplankton. The highest EPA (Eicosapentaenoic acid; 20:5ω3) production per total fatty acids was found in 2 classes of Haptophyta and in Ochrophyta, while Dinophyta and the Haptophyte Emiliana huxleyi show the highest production of DHA (Docosahexaenoic acid; 22:6ω3). An important precursor for EPA, Stearidonic acid (SDA, 18:4ω3) is found in high proportions in Cryptophyta and the Chlorophta class Pyramimonadophyceae. Per unit of carbon, Chlorophyta and Cyanobacteria were the poorest producers of highly unsaturated fatty acids (HUFA). The remaining phyla had a similar HUFA contribution per unit of carbon but with different compositions. The nutritional and environmental effects on the phytoplankton PUFA production is summarized and shows a lowering of the PUFA content under stressful environmental conditions.

How does high DHA fish oil affect health? A systematic review of evidence

Abstract: The health benefits of fish oil, and its omega-3 long chain polyunsaturated fatty acid content, have attracted much scientific attention in the last four decades. Fish oils that contain higher amounts of eicosapentaenoic acid (EPA; 20:5n-3) than docosahexaenoic acid (DHA; 22:6n-3), in a distinctive ratio of 18/12, are typically the most abundantly available and are commonly studied. Although the two fatty acids have traditionally been considered together, as though they were one entity, different physiological effects of EPA and DHA have recently been reported. New oils containing a higher quantity of DHA compared with EPA, such as fractionated and concentrated fish oil, tuna oil, calamari oil and microalgae oil, are increasingly becoming available on the market, and other oils, including those extracted from genetically modified oilseed crops, soon to come. This systematic review focuses on the effects of high DHA fish oils on various human health conditions, such as the heart and cardiovascular system, the brain and visual function, inflammation and immune function and growth/Body Mass Index. Although inconclusive results were reported in several instances, and inconsistent outcomes observed in others, current data provides substantiated evidence in support of DHA being a beneficial bioactive compound for heart, cardiovascular and brain function, with different, and at times complementary, effects compared with EPA. DHA has also been reported to be effective in slowing the rate of cognitive decline, while its possible effects on depression disorders are still unclear. Interestingly, gender- and age- specific divergent roles for DHA have also been reported. This review provides a comprehensive collection of evidence and a critical summary of the documented physiological effects of high DHA fish oils for human health.

The Influence of Omega-3 Fatty Acids on Skeletal Muscle Protein Turnover in Health, Disuse, and Disease

Abstract: Ingestion of omega-3 fatty acids is known to exert favorable health effects on a number of biological processes such as improved immune profile, enhanced cognition, and optimized neuromuscular function. Recently, data have emerged demonstrating a positive influence of omega-3 fatty acid intake on skeletal muscle. For instance, there are reports of clinically-relevant gains in muscle size and strength in healthy older persons with omega-3 fatty acid intake as well as evidence that omega-3 fatty acid ingestion alleviates the loss of muscle mass and prevents decrements in mitochondrial respiration during periods of muscle-disuse. Cancer cachexia that is characterized by a rapid involuntary loss of lean mass may also be attenuated by omega-3 fatty acid provision. The primary means by which omega-3 fatty acids positively impact skeletal muscle mass is via incorporation of eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) into membrane phospholipids of the sarcolemma and intracellular organelles. Enrichment of EPA and DHA in these membrane phospholipids is linked to enhanced rates of muscle protein synthesis, decreased expression of factors that regulate muscle protein breakdown, and improved mitochondrial respiration kinetics. However, exactly how incorporation of EPA and DHA into phospholipid membranes alters these processes remains unknown. In this review, we discuss the interaction between omega-3 fatty acid ingestion and skeletal muscle protein turnover in response to nutrient provision in younger and older adults. Additionally, we examine the role of omega-3 fatty acid supplementation in protecting muscle loss during muscle-disuse and in cancer cachexia, and critically evaluate the molecular mechanisms that underpin the phenotypic changes observed in skeletal muscle with omega-3 fatty acid intake.

Omega-3 fatty acid-derived mediators that control inflammation and tissue homeostasis

Abstract: Omega-3 polyunsaturated fatty acids (PUFAs), including eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid, display a wide range of beneficial effects in humans and animals. Many of the biological functions of PUFAs are mediated via bioactive metabolites produced by fatty acid oxygenases such as cyclooxygenases, lipoxygenases and cytochrome P450 monooxygenases. Liquid chromatography-tandem mass spectrometry-based mediator lipidomics revealed a series of novel bioactive lipid mediators derived from omega-3 PUFAs. Here, we describe recent advances on omega-3 PUFA-derived mediators, mainly focusing on their enzymatic oxygenation pathway, and their biological functions in controlling inflammation and tissue homeostasis.

New Insights into Mechanisms of Action for Omega-3 Fatty Acids in Atherothrombotic Cardiovascular Disease

Abstract: Treatment of hypercholesterolemia with statins results in significant reductions in cardiovascular risk; however, individuals with well-controlled low-density lipoprotein cholesterol (LDL-C) levels, but persistent high triglycerides (TG), remain at increased risk. Genetic and epidemiologic studies have shown that elevated fasting TG levels are associated with incident cardiovascular events. At effective doses, omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), lower TG levels but may have additional atheroprotective properties compared to other TG-lowering therapies such as niacin and fibrates. The purpose of this review is to evaluate mechanisms related to the potential benefits of omega-3 fatty acids in atherothrombotic disease. Large randomized clinical trials are currently under way to test the cardiovascular benefits of omega-3 fatty acids at a pharmacologic dosage (4 g/day). A large randomized trial with a prescription EPA-only formulation was shown to reduce a composite of cardiovascular events by 25% in statin-treated patients with established cardiovascular disease or diabetes and other CV risk factors. EPA and DHA have distinct tissue distributions as well as disparate effects on membrane structure and lipid dynamics, rates of lipid oxidation, and signal transduction pathways. Compared to other TG-lowering therapies, EPA has been found to inhibit cholesterol crystal formation, inflammation, and oxidative modification of atherogenic lipoprotein particles. The anti-inflammatory and endothelial benefits of EPA are enhanced in combination with a statin. Omega-3 fatty acids like EPA only at a pharmacologic dose reduce fasting TG and interfere with mechanisms of atherosclerosis that results in reduced cardiovascular events. Additional mechanistic trials will provide further insights into their role in reducing cardiovascular risk in subjects with well-managed LDL-C but elevated TG levels.

Influence of nitrogen limitation on lipid accumulation and EPA and DHA content in four marine microalgae for possible use in aquafeed

Abstract: Microalgae are regarded as a promising alternative that can replace fishmeal and fish oil in aquaculture. Under N-limitation, many microalgae species change their carbon storage patterns in favor of neutral lipids (NLs) mainly in the form of triacylglycerol (TAG), but fatty acids in polar lipids (PL) are nutritionally more available for fish than those esterified into NLs. In the present study, the effect of N-limitation on the lipid content and fatty acid profiles in different lipid class of Phaeodactylum tricornutum, Isochrysis aff. galbana clone T-Iso, Rhodomonas baltica and Nannochloropsis oceanica were investigated. The microalgae cells were cultivated by two different methods, batch and semi-continuous culture, to create strong and moderate N-limitation, and this in turn will significantly affect the biomass and lipid productivity. All four species accumulated lipids mainly in the form of TAG in response to strong nitrogen limitation. N. oceanica, however accumulated 51% of the dry weight as lipid in moderate nitrogen limitation and up to 87% of the fatty acid was in TAG. Isochrysis aff. galbana clone T-Iso was the only species where the fraction of polyunsaturated fatty acid (PUFA), especially the fraction of docosahexaenoic acid (DHA) increased with increasing nitrogen limitation. Total lipid productivity showed no increase in batch culture although stronger nitrogen limitation led to lipid accumulation. P. tricornutum had the highest eicosapentaenoic acid (EPA) content, while N. oceanica showed the highest EPA productivity due to the high content of lipid. The highest DHA productivity was found in Isochrysis aff. galbana clone T-Iso from moderate N-limitation mainly due to the high biomass productivity. Based on the results from the current study, N. oceanica and T-Iso are two promising microalgae strains as long-term sustainable source of n-3 long chain -PUFAs under moderate N-limitation. As shown in the present study, increased lipid content in microalgal cells due to strong N-limitation induction may not increase the lipid productivity because biomass production usually is reduced. Therefore, a combination of approaches such as metabolic engineering, conditioning and selection may be needed to further increase the n-3 LC-PUFA productivity without substantial loss of biomass.

Alpha-Linolenic and Linoleic Fatty Acids in the Vegan Diet: Do They Require Dietary Reference Intake/Adequate Intake Special Consideration?

Abstract: Good sources of the long-chain n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) include cold-water fish and seafood; however, vegan diets (VGNs) do not include animal-origin foods. Typically, US omnivores obtain enough dietary EPA and DHA, but unless VGNs consume algal n-3 supplements, they rely on endogenous production of long-chain fatty acids. VGN diets have several possible concerns: (1) VGNs have high intakes of linoleic acid (LA) as compared to omnivore/non-vegetarian diets. (2) High intakes of LA competitively interfere with the endogenous conversion of alpha-linolenic acid (ALA) to EPA and DHA. (3) High somatic levels of LA/low ALA indicate a decreased ALA conversion to EPA and DHA. (4) Some, not all VGNs meet the Dietary Reference Intake Adequate Intake (DRI-AI) for dietary ALA and (5) VGN diets are high in fiber, which possibly interferes with fat absorption. Consequently, health professionals and Registered Dietitians/Registered Dietitian Nutritionists working with VGNs need specific essential fatty acid diet guidelines. The purpose of this review was: (1) to suggest that VGNs have a DRI-AI Special Consideration requirement for ALA and LA based on VGN dietary and biochemical indicators of status and (2) to provide suggestions to ensure that VGNs receive adequate intakes of LA and ALA.

Reduction of high-fat diet-induced liver proinflammatory state by eicosapentaenoic acid plus hydroxytyrosol supplementation: involvement of resolvins RvE1/2 and RvD1/2.

Abstract: High-fat diet (HFD)-fed mice show obesity with development of liver steatosis and a proinflammatory state without establishing an inflammatory reaction. The aim of this work was to assess the hypothesis that eicosapentaenoic acid (EPA) plus hydroxytyrosol (HT) supplementation prevents the inflammatory reaction through enhancement in the hepatic resolvin content in HFD-fed mice. Male C57BL/6J mice were fed an HFD or a control diet and supplemented with EPA (50 mg/kg/day) and HT (5 mg/kg/day) or their respective vehicles for 12 weeks. Measurements include liver levels of EPA, DHA and palmitate (gas chromatography), liver resolvins and triglyceride (TG) and serum aspartate transaminase (AST) (specific kits) and hepatic and serum inflammatory markers (quantitative polymerase chain reaction and enzyme-linked immunosorbent assay). Compared to CD, HFD induced body weight gain, liver steatosis and TG accumulation, with up-regulation of proinflammatory markers in the absence of histological inflammation or serum AST changes; these results were accompanied by higher hepatic levels of resolvins RvE1, RvE2, RvD1 and RvD2, with decreases in EPA and DHA contents. EPA+HT supplementation in HFD feeding synergistically reduced the steatosis score over individual treatments and increased the hepatic levels of EPA, DHA and resolvins, with attenuation of proinflammatory markers. Lack of progression of HFD-induced proinflammatory state into overt inflammation is associated with resolvin up-regulation, which is further increased by EPA+HT supplementation eliciting steatosis attenuation. These findings point to the importance of combined protocols in hepatoprotection due to the involvement of cross-talk mechanisms, which increase effectiveness and diminish dosages, avoiding undesirable effects.

Polyunsaturated fatty acid production by Yarrowia lipolytica employing designed myxobacterial PUFA synthases.

Abstract: Long-chain polyunsaturated fatty acids (LC-PUFAs), particularly the omega-3 LC-PUFAs eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA), have been associated with beneficial health effects. Consequently, sustainable sources have to be developed to meet the increasing demand for these PUFAs. Here, we demonstrate the design and construction of artificial PUFA biosynthetic gene clusters (BGCs) encoding polyketide synthase-like PUFA synthases from myxobacteria adapted for the oleaginous yeast Yarrowia lipolytica. Genomic integration and heterologous expression of unmodified or hybrid PUFA BGCs yielded different yeast strains with specific LC-PUFA production profiles at promising yield and thus valuable for the biotechnological production of distinct PUFAs. Nutrient screening revealed a strong enhancement of PUFA production, when cells were phosphate limited. This represents, to the best of our knowledge, highest concentration of DHA (16.8 %) in total fatty acids among all published PUFA-producing Y. lipolytica strains. Sustainable sources are needed to meet the demand for long-chain polyunsaturated fatty acids. Here the authors construct an artificial biosynthetic gene cluster in Y. lipolytica capable of producing a high concentration of PUFAs.

Metabolic engineering to enhance biosynthesis of both docosahexaenoic acid and odd-chain fatty acids in Schizochytrium sp. S31

Abstract: Docosahexaenoic acid (DHA, C22:6) and odd-chain fatty acids (OCFAs, C15:0 and C17:0) have attracted great interest, since they have been widely used in food and therapeutic industries, as well as chemical industry, such as biodiesel production and improvement. The oil-producing heterotrophic microalgae Schizochytrium sp. 31 is one of main DHA-producing strains. Recently, it was found that Schizochytrium can also synthesize OCFAs; however, contents and titers of DHA and OCFAs in Schizochytrium are still low, which limit its practical application. In this study, we found that acetyl-CoA carboxylase suffered from a feedback inhibition by C16-CoA in Schizochytrium, and relief of the inhibition resulted in improved both lipid content and the ratio of OCFAs in total fatty acids. Based on this finding, a novel strategy for elevating both DHA and OCFAs contents was established. First, the total lipid accumulation was increased by overexpressing a malic enzyme from Crypthecodinium cohnii to elevate NADPH supply. Second, the inhibition effect on acetyl-CoA carboxylase was relieved by overexpressing a codon-optimized ELO3 gene from Mortierella alpina, which encodes an elongase enzyme responsible for converting C16 into C18 fatty acids. After the above two-step engineering, contents of DHA and OCFAs were increased by 1.39- and 3.30-fold, reaching a level of 26.70 and 25.08% of dry cell weight, respectively, which are the highest contents reported so far for Schizochytrium. The titers of DHA and OCFAs were elevated by 1.08- and 2.57-fold, reaching a level of 3.54 and 3.32 g/L, respectively. Notably, the OCFAs titer achieved was 2.66-fold higher than the highest reported in Escherichia coli (1.25 g/L), implying potential value for industry application. To reveal the potential metabolic mechanism for the enhanced biosynthesis of both DHA and OCFAs, LC–MS metabolomic analysis was employed and the results showed that the pentose phosphate pathway and the glycolysis pathway were strengthened and intracellular propionyl-CoA concentration were also significantly increased in the engineered Schizochytrium, suggesting an increased supply of NADPH, acetyl-CoA, and propionyl-CoA for DHA and OCFAs accumulation. The discovery provides a new source of OCFAs production, and proposes a new strategy to improve contents and titers of both DHA and OCFAs in Schizochytrium. These will be valuable for improving commercial potential of Schizochytrium and guiding the engineering strategy in other fatty acids producing heterotrophic microalga.

Dietary Bioactive Fatty Acids as Modulators of Immune Function: Implications on Human Health.

Abstract: Diet is major modifiable risk factor for cardiovascular disease that can influence the immune status of the individual and contribute to persistent low-grade inflammation. In recent years, there has been an increased appreciation of the role of polyunsaturated fatty acids (PUFA) in improving immune function and reduction of systemic inflammation via the modulation of pattern recognition receptors (PRR) on immune cells. Extensive research on the use of bioactive lipids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and their metabolites have illustrated the importance of these pro-resolving lipid mediators in modulating signaling through PRRs. While their mechanism of action, bioavailability in the blood, and their efficacy for clinical use forms an active area of research, they are found widely administered as marine animal-based supplements like fish oil and krill oil to promote health. The focus of this review will be to discuss the effect of these bioactive fatty acids and their metabolites on immune cells and the resulting inflammatory response, with a brief discussion about modern methods for their analysis using mass spectrometry-based methods.

Role of phosphatidylcholine-DHA in preventing APOE4-associated Alzheimer's disease

Abstract: Dietary and supplemental intake of the ω-3 fatty acid docosahexaenoic acid (DHA) reduces risk of Alzheimer's disease (AD) and ameliorates symptoms. The apolipoprotein E ( APOE) 4 allele is the strongest risk factor for sporadic AD, exclusive of age. APOE4 carriers respond well to the DHA present in fish but do not respond as well to dietary supplements. The mechanisms behind this varied response remain unknown. I posit that the difference is that fish contain DHA in phospholipid form, whereas fish oil supplements do not. This influences whether DHA is metabolized to nonesterified DHA (free DHA) or a phospholipid form called lysophosphatidylcholine DHA (DHA-lysoPC). Free DHA is transported across the outer membrane leaflet of the blood-brain barrier (BBB) via passive diffusion, and DHA-lysoPC is transported across the inner membrane leaflet of the BBB via the major facilitator superfamily domain-containing protein 2A. I propose that APOE4 carriers have impaired brain transport of free DHA but not of DHA-lysoPC, as a consequence of a breakdown in the outer membrane leaflet of the BBB, putting them at increased risk for AD. Dietary sources of DHA in phospholipid form may provide a means to increase plasma levels of DHA-lysoPC, thereby decreasing the risk of AD.-Patrick, R. P. Role of phosphatidylcholine-DHA in preventing APOE4-associated Alzheimer's disease.

Omega-3 Fatty Acid Intake by Age, Gender, and Pregnancy Status in the United States: National Health and Nutrition Examination Survey 2003–2014

Abstract: Despite the importance of n-3 fatty acids for health, intakes remain below recommended levels. The objective of this study was to provide an updated assessment of fish and n-3 fatty acid intake (i.e., eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and EPA+DHA) in the United States using the 2003–2014 National Health and Nutrition Examination Survey (NHANES) data (n = 45,347)). Over this survey period, toddlers, children, and adolescents (aged 1–19) had significantly lower n-3 fatty acid intake (p < 0.001) compared to adults and seniors, which remained significant after adjusting for caloric intake. Females demonstrated lower n-3 fatty acid intake than males (p < 0.001), with adult and senior women having significantly lower intakes compared to men in the same age categories (p < 0.001) after adjustment for energy intake. Women also consumed less fish than men (5.8 versus 6.1 servings/month, p < 0.001). The estimated intakes of n-3 fatty acids in pregnant women did not differ from non-pregnant women (p = 0.6 for EPA+DHA), although pregnant women reported consuming less high n-3 fatty acid-containing fish than non-pregnant women (1.8 versus 2.6 servings/month, p < 0.001). Our findings indicate that subgroups of the population may be at higher risk of n-3 fatty acid intakes below recommended levels.

CRISPR/Cas9-mediated ablation of elovl2 in Atlantic salmon (Salmo salar L.) inhibits elongation of polyunsaturated fatty acids and induces Srebp-1 and target genes.

Abstract: Atlantic salmon can synthesize polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (20:5n-3), arachidonic acid (20:4n-6) and docosahexaenoic acid (22:6n-3) via activities of very long chain fatty acyl elongases (Elovls) and fatty acyl desaturases (Fads), albeit to a limited degree. Understanding molecular mechanisms of PUFA biosynthesis and regulation is a pre-requisite for sustainable use of vegetable oils in aquafeeds as current sources of fish oils are unable to meet increasing demands for omega-3 PUFAs. By generating CRISPR-mediated elovl2 partial knockout (KO), we have shown that elovl2 is crucial for multi-tissue synthesis of 22:6n-3 in vivo and that endogenously synthesized PUFAs are important for transcriptional regulation of lipogenic genes in Atlantic salmon. The elovl2-KOs showed reduced levels of 22:6n-3 and accumulation of 20:5n-3 and docosapentaenoic acid (22:5n-3) in the liver, brain and white muscle, suggesting inhibition of elongation. Additionally, elovl2-KO salmon showed accumulation of 20:4n-6 in brain and white muscle. The impaired synthesis of 22:6n-3 induced hepatic expression of sterol regulatory element binding protein-1 (srebp-1), fatty acid synthase-b, Δ6fad-a, Δ5fad and elovl5. Our study demonstrates key roles of elovl2 at two penultimate steps of PUFA synthesis in vivo and suggests Srebp-1 as a main regulator of endogenous PUFA synthesis in Atlantic salmon.

FADS1 and FADS2 Polymorphisms Modulate Fatty Acid Metabolism and Dietary Impact on Health.

Abstract: Variants in the FADS gene cluster modify the activity of polyunsaturated fatty acid (PUFA) desaturation and the lipid composition in human blood and tissue. FADS variants have been associated with ...

Omega Fatty Acids and Inflammatory Bowel Diseases: An Overview.

Abstract: Inflammatory bowel diseases (IBD) are chronic, inflammatory processes that affect the gastrointestinal tract and are mainly represented by ulcerative colitis (UC) and Crohn’s disease (CD). Omega 3 (ω3) fatty acids (eicosapentanoic acid and docosahexaenoic acid) show an indispensable role in the inflammatory processes and, for these reasons, we aimed to review the effects of these acids on UC and CD. Databases such as PUMED and EMBASE were searched, and the final selection included fifteen studies that fulfilled the inclusion criteria. The results showed that ω3 fatty acids reduce intestinal inflammation, induce and maintain clinical remission in UC patients, and are related with the reduction of proinflammatory cytokines, decrease disease activity and increase the quality of life of CD patients. Furthermore, the consumption of these fatty acids may be related to a reduced risk of developing IBD. Many studies have shown the beneficial effects of ω3 as adjunctive in the treatment or prevention of UC or CD. Nevertheless, most were performed with a small number of patients and there are many variations in the mode of consumption, the type of food or the type of formulation used. All these factors substantially interfere with the results and do not allow reliable comparisons.

Vegan diet in children and adolescents. Recommendations from the French-speaking Pediatric Hepatology, Gastroenterology and Nutrition Group (GFHGNP).

Abstract: The current craze for vegan diets has an effect on the pediatric population. This type of diet, which does not provide all the micronutrient requirements, exposes children to nutritional deficiencies. These can have serious consequences, especially when this diet is introduced at an early age, a period of significant growth and neurological development. Even if deficiencies have less impact on older children and adolescents, they are not uncommon and consequently should also be prevented. Regular dietary monitoring is essential, vitamin B12 and vitamin D supplementation is always necessary, while iron, calcium, docosahexaenoic acid, and zinc should be supplemented on a case-by-case basis.