Concentration Of Omega-6 Fatty Acids Research Articles

Associations between plasma fatty acid concentrations and schizophrenia: a two-sample Mendelian randomisation study

Although studies suggest that concentrations of omega-3 and omega-6 fatty acids are lower in individuals with schizophrenia, evidence for beneficial effects of fatty acid supplementation is scarce. Therefore, in this study, we aimed to determine whether omega-3 and omega-6 fatty acid concentrations are causally related to schizophrenia. We did a two-sample Mendelian randomisation study, using deidentified summary-level data that were publicly available. Exposure-outcome relationships were evaluated using the inverse variance weighted two-sample Mendelian randomisation method using results from genome-wide association studies (GWASs) of fatty acid concentrations and schizophrenia. GWAS results were available for European (fatty acids) and European and Asian (schizophrenia) ancestry samples. Overall age and gender information were not calculable from the summary-level GWAS results. Weighted median, weighted mode, and Mendelian randomisation Egger regression methods were used as sensitivity analyses. To address underlying mechanisms, further analyses were done using single instruments within the FADS gene cluster and ELOVL2 gene locus. FADS gene cluster and ELOVL2 gene causal effects on schizophrenia were calculated by dividing the single nucleotide polymorphism (SNP)-schizophrenia effect estimate by the SNP-fatty acid effect estimate with standard errors derived using the first term from a delta method expansion for the ratio estimate. Multivariable Mendelian randomisation was used to estimate direct effects of omega-3 fatty acids on schizophrenia, independent of omega-6 fatty acids, lipoproteins (ie, HDL and LDL), and triglycerides. Mendelian randomisation analyses indicated that long-chain omega-3 and long-chain omega-6 fatty acid concentrations were associated with a lower risk of schizophrenia (eg, inverse variance weighted odds ratio [OR] 0·83 [95% CI 0·75-0·92] for docosahexaenoic acid). By contrast, there was weak evidence that short-chain omega-3 and short-chain omega-6 fatty acids were associated with an increased risk of schizophrenia (eg, inverse variance weighted OR 1·07 [95% CI 0·98-1·18] for α-linolenic acid). Effects were consistent across the sensitivity analyses and the FADS single-SNP analyses, suggesting that long-chain omega-3 and long-chain omega-6 fatty acid concentrations were associated with lower risk of schizophrenia (eg, OR 0·74 [95% CI 0·58-0·96] for docosahexaenoic acid) whereas short-chain omega-3 and short-chain omega-6 fatty acid concentrations were associated with an increased risk of schizophrenia (eg, OR 1·08 [95% CI 1·02-1·15] for α-linolenic acid). By contrast, estimates from the ELOVL2 single-SNP analyses were more imprecise and compatible with both risk-increasing and protective effects for each of the fatty acid measures. Multivariable Mendelian randomisation indicated that the protective effect of docosahexaenoic acid on schizophrenia persisted after conditioning on other lipids, although evidence was slightly weaker (multivariable inverse variance weighted OR 0·84 [95% CI 0·71-1·01]). Our results are compatible with the protective effects of long-chain omega-3 and long-chain omega-6 fatty acids on schizophrenia, suggesting that people with schizophrenia might have difficulty converting short-chain polyunsaturated fatty acids to long-chain polyunsaturated fatty acids. Further studies are required to determine whether long-chain polyunsaturated fatty acid supplementation or diet enrichment might help prevent onset of schizophrenia. National Institute for Health Research Biomedical Research Centre at University Hospitals Bristol and Weston NHS Foundation Trust and the University of Bristol.

Influence of different intravenous lipid emulsions on fatty acid status and laboratory and clinical outcomes in adult patients receiving home parenteral nutrition: A systematic review

Patients who have chronic intestinal failure require home parenteral nutrition (HPN) support. Intravenous lipid emulsions (IVLEs) are a vital part of HPN. The conventional IVLE is based on pure soybean oil, which contains a high concentration of omega-6 fatty acids. Alternative IVLEs are commercially available. These contain various oil blends and have different fatty acid compositions from soybean oil that could provide benefit to patients on HPN. The aim of this systematic review is to assess the effects of different IVLEs in adult patients requiring HPN. A systematic literature search was conducted up to October 2019 using relevant search terms in the Medline, EMBASE and CINAHL databases. Only randomised controlled trials (RCTs) in adults on HPN that compared two or more IVLEs were included. Data were extracted and the Cochrane Collaboration's tool for assessing risk of bias was used. Six articles were identified for inclusion in this systematic review. Studies differed according to sample size, duration and the IVLEs compared. Four studies found no increased risk of adverse effects related to the different IVLEs, whilst one study found a higher frequency of serious adverse events with soybean oil. One study found higher serum α-tocopherol with the blend of soybean oil, medium chain triglycerides, olive oil and fish oil. Inflammatory markers were not affected by different IVLEs in three studies. Differences in liver function tests were minimal, but one study found slight abnormalities in patients receiving soybean oil. IVLEs containing olive oil or fish oil modified the blood fatty acid profile. No studies reported essential fatty acid deficiency. There may be benefits of using alternative IVLEs to soybean oil-based emulsions in adults requiring HPN, although there is currently insufficient evidence to determine superiority of one formulation over another. More and larger RCTs are required in this area.

Serum omega-3 and omega-6 fatty acid concentrations and natural fertility.

Are serum omega-3 and omega-6 essential fatty acid concentrations associated with the probability of conceiving? There is no strong association between serum concentrations of omega-3 and omega-6 fatty acids and the probability of conceiving naturally. Omega-3 and omega-6 fatty acid serum concentrations have been shown to play an important role in reproduction in animal models, while conflicting results have been reported in human studies of infertile women. It is unknown to what extent omega fatty acid serum concentrations impact natural fertility. A nested, case-control study was conducted consisting of 200 participants [fertile: conceived within 3cycles of attempt (n= 50), subfertile: conceived within 4 and 12cycles of attempt (n= 100) and infertile: did not conceive within 12cycles of attempt (n= 50)] randomly selected from the Time to Conceive cohort, a prospective time-to-pregnancy study (2008 to 2015). In the Time to Conceive study, women aged 30-44years who were trying to conceive for <3months and had no history of infertility were recruited and followed until the end of their pregnancy or ~1year of pregnancy attempt. For this study, serum collected early in the woman's pregnancy attempt was analysed for anti-Müllerian hormone (AMH) and omega-3 and omega-6 fatty acid concentrations by liquid chromatography-mass spectrometry. The primary outcome was a positive home pregnancy test. The secondary outcomes were miscarriage and serum AMH level. A discrete-time Cox proportional hazards model was used to estimate the fecundability ratio. The odds ratios for miscarriage were calculated using logistic regression. The association between serum omega fatty acid concentrations and AMH level (natural log transformed) was analysed using Pearson's Correlation. A total of 200 women provided 1321cycles for analysis.Mean omega-3, omega-6 and omega-6:omega-3 ratios did not significantly differ between the fertile, subfertile and infertile groups. There were no associations (all fecundability ratios ~1.0) between pregnancy and individual omega-3 fatty acid concentrations, including alpha-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid, or omega-6 fatty acids, including linoleic acid (LA), dihommo-gamma linolenic acid and arachidonic acid. There was no significant association between any individual omega fatty acid serum concentration and the age-adjusted odds of miscarriage. No association was found between any serum omega fatty acid concentration and AMH. This study is limited by the sample size. Omega-3 and omega-6 fatty acid concentrations were derived from serum provided at a single timepoint in the first cycle of enrollment. Serum concentrations may therefore not be representative of all critical timepoints in the menstrual cycle or throughout their attempts to conceive. Additionally, women enrolled in this study were 30years of age and older, and therefore the findings may not apply to younger women. These data would suggest that omega-3 and omega-6 serum levels are not associated with natural fertility or risk of miscarriage. However, due to the above-mentioned limitations, future investigation is still needed to determine whether omega-3 fatty acid supplementation may benefit women planning to conceive naturally. This study was supported by the Division of Reproductive Endocrinology and Infertility at the University of North Carolina at Chapel Hill, by the NIH/NICHD (R21 HD060229-01 and R01 HD067683-01) and, in part, by the Intramural Research Program of the National Institute of Environmental Health Sciences (Z01ES103333). Dr. Jukic received vitamin D supplements for a research study from Theralogix, Inc. The authors have no other conflicts of interest to disclose. N/A.

Testing the Effects of Dietary Seafood Consumption on Depressive Symptoms.

This chapter presents a protocol for assessing the effects dietary seafood consumption on depressive symptoms. We designed a cross-sectional study of 206 participants recruited in two Torres Strait Island communities. Depressive symptoms were assessed using the adapted Patient Health Questionnaire-9 (aPHQ-9), diet was analyzed with a structured questionnaire, omega-3 and omega-6 fatty acid concentrations were measured via a capillary dried blood spot system, and plasma levels of triglycerides and cholesterol were measured by gas-phase chromatography. Finally, we tested the relationship between seafood consumption, blood lipid concentrations, and depression scores using independent samples t-tests and a logistic and quantile regression model.

Evaluating Pig Performance, Carcass Merit and Processed Pork Quality when Chestnuts and Acorns are fed to Duroc-Influenced Pig Genetics During Late Finishing

ObjectivesThe objective of this study was to determine the effects of feeding chestnuts and acorns on growth performance, carcass quality and further processed products of Duroc/Duroc crossbred finishing barrows.Materials and MethodsBarrows (n = 30) were individually housed in pens, blocked by body weight and randomly assigned to one of three treatments: control (n = 10), inclusion of acorns at 15% of the diet (n = 7), inclusion of chestnuts at 15% of the diet (n = 13). Pigs were fed ad libitum for 28 d prior to harvest. Feed refusal and individual pig weights were collected every 7 d and used to calculate average daily gain (ADG), gain-to-feed (G:F), and average daily feed intake (ADFi). Following harvest, carcass quality was determined by objective color (L*, a* and b*), fat composition and marbling scores. Fat samples were removed from four fat depots (backfat, seam, jowl, kidney and pelvic) and analyzed for fatty acid composition. Sample chops were removed between the 10th and 11th rib of the left side of each carcass and analyzed for fatty acid composition, moisture and fat content. Bellies were removed from the left side of each carcass, further processed into bacon slabs and analyzed for slice quality, fatty acid composition, moisture and fat content. Carcass characteristics and bacon quality were analyzed using GLM procedure of SAS. Growth performance and fatty acid composition were analyzed using MIXED procedure of SAS. Significance was determined at P-value &lt; 0.05.ResultsNo differences were detected for ADG and ADFi across treatments (P &gt; 0.05). Barrows fed chestnut diets had a greater G:F when compared to control (P &lt; 0.05) or acorn fed barrows (P &lt; 0.05). Dietary treatments did not impact (P &gt; 0.05) carcass characteristics or carcass quality. Inclusion of chestnuts or acorns within the diet did not impact (P &gt; 0.05) moisture and fat content of chops and bacon slices (P &gt; 0.05). Moreover, feeding acorns led to similar concentrations (P &gt; 0.05) of palmitoleic acid (16:1) and linoleic acid (18:2n6c) when compared to the control diet. However, feeding diets containing acorns led to greater proportions (P &lt; 0.01) of palmitoleic acid and linoleic acid similar to barrows fed diets containing chestnuts. No difference (P &gt; 0.05) for stearic acid (18:0) were observed between control and chestnut treatments, however, both were found to have greater amounts (P &lt; 0.01) of stearic acid when compared to the acorn treatment. Acorns increased (P &lt; 0.01) the total concentration of omega-6 fatty acids (n-6) when compared to chestnut diets, but no differences (P &gt; 0.05) were observed between acorn and control diets. Inclusion of acorns reduced (P &lt; 0.05) total saturated fatty acids (SFA) when compared to control and chestnut treatments; however total polyunsaturated fatty acids (PUFA) were increased (P &lt; 0.05) when acorns were included in the diet. When evaluating PUFA:SFA ratio, no differences (P &gt; 0.05) were found between control and chestnut diets. Including acorns in the diet, resulted in an increased (P &lt; 0.05) PUFA:SFA ratio.ConclusionInclusion of acorns and chestnuts did not negatively impact carcass characteristics, carcass quality or bacon quality, nevertheless, including acorns altered overall fatty acid composition while minimal differences were observed between diets containing chestnuts and the control.

Serum omega-3 and omega-6 fatty acid concentrations and fecundity

Omega fatty acid serum concentrations have been shown to play an important role in reproduction in animal models, with conflicting results in human studies. We sought to determine the association between serum omega-3 and omega-6 fatty acid concentrations and the probability of conceiving, the risk of miscarriage, and ovarian reserve.

Evaluating Pig Performance, Carcass Merit and Processed Pork Quality when Chestnuts and Acorns are fed to Duroc-Influenced Pig Genetics During Late Finishing

ObjectivesThe objective of this study was to determine the effects of feeding chestnuts and acorns on growth performance, carcass quality and further processed products of Duroc/Duroc crossbred finishing barrows.Materials and MethodsBarrows (n = 30) were individually housed in pens, blocked by body weight and randomly assigned to one of three treatments: control (n = 10), inclusion of acorns at 15% of the diet (n = 7), inclusion of chestnuts at 15% of the diet (n = 13). Pigs were fed ad libitum for 28 d prior to harvest. Feed refusal and individual pig weights were collected every 7 d and used to calculate average daily gain (ADG), gain-to-feed (G:F), and average daily feed intake (ADFi). Following harvest, carcass quality was determined by objective color (L*, a* and b*), fat composition and marbling scores. Fat samples were removed from four fat depots (backfat, seam, jowl, kidney and pelvic) and analyzed for fatty acid composition. Sample chops were removed between the 10th and 11th rib of the left side of each carcass and analyzed for fatty acid composition, moisture and fat content. Bellies were removed from the left side of each carcass, further processed into bacon slabs and analyzed for slice quality, fatty acid composition, moisture and fat content. Carcass characteristics and bacon quality were analyzed using GLM procedure of SAS. Growth performance and fatty acid composition were analyzed using MIXED procedure of SAS. Significance was determined at P-value < 0.05.ResultsNo differences were detected for ADG and ADFi across treatments (P > 0.05). Barrows fed chestnut diets had a greater G:F when compared to control (P < 0.05) or acorn fed barrows (P < 0.05). Dietary treatments did not impact (P > 0.05) carcass characteristics or carcass quality. Inclusion of chestnuts or acorns within the diet did not impact (P > 0.05) moisture and fat content of chops and bacon slices (P > 0.05). Moreover, feeding acorns led to similar concentrations (P > 0.05) of palmitoleic acid (16:1) and linoleic acid (18:2n6c) when compared to the control diet. However, feeding diets containing acorns led to greater proportions (P < 0.01) of palmitoleic acid and linoleic acid similar to barrows fed diets containing chestnuts. No difference (P > 0.05) for stearic acid (18:0) were observed between control and chestnut treatments, however, both were found to have greater amounts (P < 0.01) of stearic acid when compared to the acorn treatment. Acorns increased (P < 0.01) the total concentration of omega-6 fatty acids (n-6) when compared to chestnut diets, but no differences (P > 0.05) were observed between acorn and control diets. Inclusion of acorns reduced (P < 0.05) total saturated fatty acids (SFA) when compared to control and chestnut treatments; however total polyunsaturated fatty acids (PUFA) were increased (P < 0.05) when acorns were included in the diet. When evaluating PUFA:SFA ratio, no differences (P > 0.05) were found between control and chestnut diets. Including acorns in the diet, resulted in an increased (P < 0.05) PUFA:SFA ratio.ConclusionInclusion of acorns and chestnuts did not negatively impact carcass characteristics, carcass quality or bacon quality, nevertheless, including acorns altered overall fatty acid composition while minimal differences were observed between diets containing chestnuts and the control.

EPA supplementation improves teacher‐rated behaviour and oppositional symptoms in children with ADHD

Measure efficacy of eicosapentaenoic acid (EPA) in children with attention deficit hyperactivity disorder (ADHD). Randomized controlled trial (RCT) of 0.5 g EPA or placebo (15 weeks) in 92 children (7-12 years) with ADHD. Efficacy measure was Conners' Parent/Teacher Rating Scales (CPRS/CTRS). Fatty acids were analysed in serum phospholipids and red blood cell membranes (RBC) at baseline and endpoint with gas chromatography. EPA improved CTRS inattention/cognitive subscale (p = 0.04), but not Conners' total score. In oppositional children (n = 48), CTRS total score improved ≥25% in 48% of the children receiving EPA vs. 9% for placebo [effect size (ES) 0.63, p = 0.01]. In less hyperactive/impulsive children (n = 44), ≥25% improvement was seen in 36% vs. 18% (ES 0.41, n.s.), and with both these types of symptoms 8/13 with EPA vs. 1/9 for placebo improved ≥25% (p = 0.03). Children responding to treatment had lower EPA concentrations (p = 0.02), higher AA/EPA (p = 0.005) and higher AA/DHA ratios (p = 0.03) in serum at baseline. Similarly, AA/EPA (p = 0.01), AA/DHA (p = 0.038) and total omega-6/omega-3 ratios (p = 0.028) were higher in RBC, probably because of higher AA (p = 0.011). Two ADHD subgroups (oppositional and less hyperactive/impulsive children) improved after 15-week EPA treatment. Increasing EPA and decreasing omega-6 fatty acid concentrations in phospholipids were related to clinical improvement.

Omega-3 and omega-6 fatty acid concentrations in red blood cell membranes relate to schizotypal traits in healthy adults

Reduced omega-3 and omega-6 fatty acids in red blood cell (RBC) membranes are often found in patients with schizophrenia. Here we investigated whether membrane concentrations of these fatty acids might vary as a function of schizotypal traits in non-psychotic individuals. Twenty-five healthy adults completed the O-LIFE schizotypal trait inventory and fatty acid composition of their venous blood samples was analysed via gas–liquid chromatography. Correlations between schizotypy measures and RBC fatty acids were examined and comparisons made between groups high and low on fatty acid measures and schizotypy scores. The omega-6 fatty acids arachidonic, adrenic and docosapentaenoic acid were directly related to positive schizotypal trait measures, as were most omega-3 fatty acids, but none were related to a negative, withdrawn form of schizotypy. Our findings of high RBC concentrations of omega-3 and omega-6 fatty acids in healthy adults with positive schizotypal traits clearly contrast with the low levels often found in schizophrenia, but are quite consistent with evidence that omega-3 fatty acids (notably EPA) can be useful in the treatment of schizophrenic illness.

Omega-3 fatty acids in boys with behavior, learning, and health problems

The purpose of the study reported here was to compare behavior, learning, and health problems in boys ages 6 to 12 with lower plasma phospholipid total omega-3 or total omega-6 fatty acid levels with those boys with higher levels of these fatty acids. A greater frequency of symptoms indicative of essential fatty acid deficiency was reported by the parents of subjects with lower plasma omega-3 or omega-6 fatty acid concentrations than those with higher levels. A greater number of behavior problems, assessed by the Conners' Rating Scale, temper tantrums, and sleep problems were reported in subjects with lower total omega-3 fatty acid concentrations. Additionally, more learning and health problems were found in subjects with lower total omega-3 fatty acid concentrations. (Only more colds and more antibiotic use were reported by those subjects with lower total omega-6 fatty acids.) These findings are discussed in relation to recent findings for omega-3 experimentally deprived animals.