Online Library: Omega 3 fatty acids
Prenatal fatty acid status and child adiposity at age 3 y: results from a US pregnancy cohort
Source: Am J Clin Nutr 2011; 93(4):780-788
Affiliation: Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, USA
Abstract: In this study an enhanced maternal-fetal n-3 PUFA status was associated with lower childhood adiposity.
High consumption of omega-3 polyunsaturated fatty acids decrease plasma homocysteine: A meta-analysis of randomized, placebo-controlled trials.
Source: Nutrition. 2011 Apr 16. [Epub ahead of print]
Affiliation: Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China; APCNS Centre of Nutrition and Food Safety, Hangzhou, China.
Abstract: High consumption of ω-3 polyunsaturated fatty acids (PUFAs) has been associated with lower plasma homocystine (Hcy) levels, but intervention studies in humans have been inconclusive. The objective was to systematically evaluate the effects of ω-3 PUFA supplementation on plasma Hcy levels. Eleven trials including 702 subjects were analyzed. The outcomes studied were plasma Hcy level. Eleven randomized, placebo-controlled trials were included in this meta-analysis. Supplementation with ω-3 PUFAs was associated with a significant decrease in plasma Hcy level (weighted mean difference -1.59 μmol/L, 95% confidence interval -2.34 to -0.83) compared with control subjects. This meta-analysis suggested that ω-3 PUFA supplementation can decrease plasma Hcy levels. The implications of these findings remain to be elucidated.
Fatty acids, the immune response, and autoimmunity: a question of n-6 essentiality and the balance between n-6 and n-3.
Source: Lipids. 2003;38(4):323-341
Affiliation: School of Chemical and Life Sciences, University of Greenwich at Medway, Chatham Maritime, Kent ME4 4TB, United Kingdom.
Abstract: The essentiality of n-6 polyunsaturated fatty acids (PUFA) is described in relation to a thymus/thymocyte accretion of arachidonic acid (20:4n-6, AA) in early development, and the high requirement of lymphoid and other cells of the immune system for AA and linoleic acid (1 8:2n-6, LA) for membrane phospholipids. Low n-6 PUFA intakes enhance whereas high intakes decrease certain immune functions. Evidence from in vitro and in vivo studies for a role of AA metabolites in immune cell development and functions shows that they can limit or regulate cellular immune reactions and can induce deviation toward a T helper (Th)2-like immune response. In contrast to the effects of the oxidative metabolites of AA, the longer-chain n-6 PUFA produced by gamma-linolenic acid (18:3n-6, GLA) feeding decreases the Th2 cytokine and immunoglobulin (Ig)G1 antibody response. The n-6 PUFA, GLA, dihomo-gamma-linolenic acid (20:3n-6, DHLA) and AA, and certain oxidative metabolites of AA can also induce T-regulatory cell activity, e.g., transforming growth factor (TGF)-beta-producing T cells; GLA feeding studies also demonstrate reduced proinflammatory interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha production. Low intakes of long-chain n-3 fatty acids (fish oils) enhance certain immune functions, whereas high intakes are inhibitory on a wide range of functions, e.g., antigen presentation, adhesion molecule expression, Th1 and Th2 responses, proinflammatory cytokine and eicosanoid production, and they induce lymphocyte apoptosis. Vitamin E has a demonstrable critical role in long-chain n-3 PUFA interactions with immune functions, often reversing the effects of fish oil. The effect of dietary fatty acids on animal autoimmune disease models depends on both the autoimmune model and the amount and type of fatty acids fed. Diets low in fat, essential fatty acid deficient (EFAD), or high in long-chain n-3 PUFA from fish oils increase survival and reduce disease severity in spontaneous autoantibody-mediated disease, whereas high-fat LA-rich diets increase disease severity. In experimentally induced T cell-mediated autoimmune disease, EFAD diets or diets supplemented with long-chain n-3 PUFA augment disease, whereas n-6 PUFA prevent or reduce the severity. In contrast, in both T cell- and antibody-mediated autoimmune disease, the desaturated/elongated metabolites of LA are protective. PUFA of both the n-6 and n-3 families are clinically useful in human autoimmune-inflammatory disorders, but the precise mechanisms by which these fatty acids exert their clinical effects are not well understood. Finally, the view that all n-6 PUFA are proinflammatory requires revision, in part, and their essential regulatory and developmental role in the immune system warrants appreciation.
Nutritional Supplementation Aids Weight Gain in HIV-Infected Patients Experiencing Weight Loss
Source: Eur Rev Med Pharmacol Sci, 2010; 14(5): 449-54
Affiliation: Institute of Endocrinology and Nutrition (I.E.N.) School of Medicine, University of Valladolid, Spain
Abstract: (Nutritional treatment for ambulatory patients with acquired immunodeficiency virus infection and previous weight loss using a formula enriched with n3 fatty acids: a randomized prospective trial.)
In a randomized study involving 30 patients infected with HIV who had been experiencing progressive weight loss, oral nutritional supplementation both with or without the addition of omega-3 fatty acids for a period of 3 months was found to be associated with increases in intakes of calories and protein and a significant increase in weight. The authors conclude, "Oral nutritional supplements for a 3-months period were well tolerated and resulted in body weight gain in HIV-infected patients with previous weight loss."
Higher Intake of Omega-3 Fatty Acids May Reduce Risk of Distal Large Bowel Cancer
Source: Am J Epidemiol, 2010; 171(9): 969-979
Affiliation: Epidemiology Branch, National Institute of Environmental Health Sciences,USA
Abstract: In a population-based, case-control study of 1,503 white (716 cases; 787 controls) and 369 African American (213 cases; 156 controls) adults, results indicate that dietary intake of long-chain omega-3 polyunsaturated fatty acids (PUFAs) may be inversely associated with risk of distal large bowel cancer. The authors conclude, "Study results support the hypothesis that long-chain omega-3 PUFAs have beneficial effects in colorectal carcinogenesis. Whether or not the possible benefit of long-chain omega-3 PUFAs varies by race warrants further evaluation."
Omega-3 Fatty Acids May Reduce Postprandial Arterial Stiffness
Source: Clin Nutr, 2010;29(5):678-681
Affiliation: Hugh Sinclair Unit of Human Nutrition and Institute for Cardiovascular and Metabolic Research, Department of Food and Nutritional Sciences, University of Reading, Reading, United Kingdom
Abstract: In a study involving 25 healthy subjects (12 men, 13 women), consumption of a omega-3 polyunsaturated fatty acid-rich meal was found to improve postprandial arterial stiffness. These results suggest that consumption of omega-3 fatty acids may have beneficial effects on arterial stiffness, thereby exerting a cardioprotective effect. They conclude that their results have, "...important implications for the beneficial properties of LC n-3 PUFA and cardiovascular risk reduction."
Consumption of Fatty Fish May Lower Risk of Heart Failure in Middle-Aged and Older Women
Source: Eur J Clin Nutr, 2010;64(6):587-594
Affiliation: Department of Epidemiology, University of Alabama at Birmingham School of Public Health, Birmingham, AL, USA
Abstract: In a prospective study involving 36,234 middle-aged and older women, results indicate that moderate consumption of fatty fish and marine omega-3 fatty acids may be associated with reduced risk of heart failure (HF). The authors of this study conclude, "Moderate consumption of fatty fish (1-2 servings per week) and marine omega-3 fatty acids were associated with a lower rate of first HF hospitalization or death in this population."
Safety and efficacy of fish oil-enriched parenteral nutrition regimen on postoperative patients undergoing major abdominal surgery: a meta-analysis of randomized controlled trials.
Source: JPEN. Journal of parenteral and enteral nutrition. 2010; 34(4):387-94.
Affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, China.
Abstract: To evaluate the safety and efficacy of a fish oil-enriched parenteral nutrition regimen in patients undergoing major abdominal surgery, a meta-analysis of randomized controlled trials was conducted. An electronic search of PubMed, MEDLINE, EMBASE, Academic Search Premier, and China National Knowledge Infrastructure databases was performed in March 2009. RevMan 5.0 was used for statistical analysis. Conclusions: Based on the meta-analysis, fish oil-supplemented parenteral nutrition was safe, improved clinical outcomes, and altered the fatty acid pattern as well as leukotriene synthesis. More laboratory parameters should be considered in future meta-analyses.
Fish, n-3 Fatty Acids, and Cardiovascular Diseases in Women of Reproductive Age: A Prospective Study in a Large National Cohort
Source: Hypertension. 2011 Dec 5. [Epub ahead of print]
Affiliation: Maternal Nutrition Group, Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark; Faculty of Food Science and Nutrition, School of Health Sciences, University of Iceland, Læknagardur, Reykjavik, Iceland;
Abstract: Previous studies have indicated a protective effect of long-chain n-3 polyunsaturated fatty acids (LCn3FAs) against cardiovascular disease; however, women are underrepresented in cardiovascular research. The aim of this study was to explore the association between intake of LCn3FAs and the risk of cardiovascular disease in a large prospective cohort of young women (mean age at baseline: 29.9 years [range: 15.7-46.9]). Exposure information on 48 627 women from the Danish National Birth Cohort was linked to the Danish National Patients Registry for information on events of hypertensive, cerebrovascular, and ischemic heart disease used to define a combined measure of cardiovascular diseases. Intake of fish and LCn3FAs was assessed by a food-frequency questionnaire and telephone interviews. During follow-up (1996-2008; median: 8 years), 577 events of cardiovascular disease were identified. Low LCn3FA intake was associated with an increased risk of cardiovascular disease. Restricting the sample to women who had consistently reported similar frequencies of fish intake across 3 different dietary assessment occasions tended to strengthen the relationship. Furthermore, the observed associations were consistent in supplementary analyses where LCn3FA intake was averaged across the 3 dietary assessment occasions, and the associations were persistent for all 3 of the individual outcomes. These findings based on a large prospective cohort of relatively young and initially healthy women indicated that little or no intake of fish and LCn3FAs was associated with an increased risk of cardiovascular disease.
Consumption of salmon v. salmon oil capsules: effects on n-3 PUFA and selenium status
Source: British Journal of Nutrition 2011; 106 :1231-1239
Affiliation: Institute of Food, Nutrition and Human Health, Massey University, Auckland, New Zealand, Department of Human Nutrition, University of Otago, Dunedin, New Zealand
Abstract: Salmon provides long-chain (LC) n-3 PUFA and Se, which are well recognised for their health benefits. The n-3 and Se status of the New Zealand population is marginal. The objective of the present study was to compare the effects of consuming salmon v. supplementation with salmon oil on LC n-3 and Se status. Healthy volunteers (n 44) were randomly assigned to one of four groups consuming 2 × 120 g servings of salmon/week or 2, 4 or 6 salmon oil capsules/d for 8 weeks. Linear regression analysis predictive models were fitted to the capsule data to predict changes in erythrocyte LC n-3 levels with intakes of LC n-3 from capsules in amounts equivalent to that consumed from salmon. Changes in Se status (plasma Se and whole-blood glutathione peroxidase) were compared between the groups consuming salmon and capsules (three groups combined). Salmon, 2, 4 and 6 capsules provided 0•82, 0•24, 0•47 and 0•69 g/d of LC n-3 fatty acids. Salmon provided 7 μg/d and capsules < 0•02 μg/d of Se. The predictive model showed that increases in erythrocyte LC n-3 levels were similar when intakes of LC n-3 from salmon or capsules were consumed. Plasma Se increased significantly more with salmon than with capsules. LC n-3 status was similarly improved with consumption of salmon and capsules, while consuming salmon had the added benefit of increasing Se status. This is of particular relevance to the New Zealand population that has marginal LC n-3 and Se status.
Consumption of omega-3 fatty acids and fish and risk of age-related hearing loss.
Source: Am J Clin Nutr. 2010 Aug;92(2):416-21.
Affiliation: Centre for Vision Research, Department of Ophthalmology, and Westmead Millennium Institute, University of Sydney, Sydney, Australia.
Abstract: Identification of modifiable risk factors that could prevent or slow the development of age-related hearing loss (presbycusis) would be valuable. Dietary polyunsaturated fatty acid (PUFA) intake may be related to age-related hearing loss. The authors aimed to determine the association between dietary intakes of omega-3 (n-3) PUFAs and fish and the risk of presbycusis. The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss (1997-1999 to 2002-2004). The authors collected dietary data by using a semiquantitative food-frequency questionnaire and calculated PUFA and fish intakes. In 2956 participants (aged > or =50 y), they measured presbycusis, which they defined as the pure-tone average of frequencies 0.5, 1.0, 2.0, and 4.0 kHz >25 decibels of hearing loss. Conclusion: There was an inverse association between higher intakes of long-chain n-3 PUFAs and regular weekly consumption of fish and hearing loss. Dietary intervention with n-3 PUFAs could prevent or delay the development of age-related hearing loss.
Dietary intake of fish, omega-3, omega-6 polyunsaturated fatty acids and vitamin D and the prevalence of psychotic-like symptoms in a cohort of 33,000 women from the general population.
Source: BMC Psychiatry. 2010 May 26;10:38.
Affiliation: Department of Neuroscience, Psychiatry, Ulleråker, Uppsala University, Uppsala, Sweden.
Abstract: Low intake of fish, polyunsaturated fatty acids (PUFA) and vitamin D deficiency has been suggested to play a role in the development of schizophrenia. The authors wanted to evaluate the association between the intake of different fish species, PUFA and vitamin D and the prevalence of psychotic-like symptoms in a population-based study among Swedish women. Dietary intake was estimated using a food frequency questionnaire among 33,623 women aged 30-49 years at enrollment (1991/92). Information on psychotic-like symptoms was derived from a follow-up questionnaire in the years 2002/03. Participants were classified into 3 predefined levels: low, middle and high frequency of symptoms. The association between diet and psychotic-like symptoms was summarized in terms of relative risks (RR) and corresponding 95% confidence intervals and was evaluated by energy-adjusted multinomial logistic regression. 18,411 women were classified as having a low level of psychotic-like symptoms, 14 395 as middle and 817 as having a high level. The risk of high level symptoms was 53% lower among women who ate fish 3-4 times per week compared to women who never ate fish. The risk was also lower for women with a high intake of omega-3 and omega-6 PUFA compared to women with a lower intake of these fatty acids. The effect was most pronounced for omega-6 PUFAs. The RR comparing the highest to the lowest quartile of omega-6 PUFAs intake was 0.78. Women in the highest compared with the lowest quartile of vitamin D consumption experienced a 37% lower risk of psychotic-like symptoms. Conclusion: The findings raise a possibility that adult women with a high intake of fish, omega-3 or omega-6 PUFA and vitamin D have a lower rate of psychotic-like symptoms.
Effect of omega-3 fatty acids supplementation on endothelial function: a meta-analysis of randomized controlled trials.
Affiliation: State Key Laboratory of Cardiovascular Disease, Department of Evidence Based Medicine.
Abstract: Inverse association was reported between omega-3 fatty acids (FAs) supplementation and the risk of cardiovascular disease. Identifying the effect of omega-3 FAs on endothelial function may contribute to explain the association. The authors conducted a meta-analysis to assess the effect of omega-3 FAs supplementation on endothelial function, as measured by flow-mediated dilation (FMD) and endothelium-independent vasodilation (EIV). Randomized placebo-controlled trials (RCTs) were identified from the databases of PubMed, EMBASE and Cochrane library by two investigators and the pooled effects were measured by weighted mean difference (WMD), together with 95% confidence intervals (CIs). Subgroup and meta-regression analyses were used to explore the source of between-study heterogeneity. Totally 16 eligible studies involving 901 participants were finally included in meta-analysis. Compared with placebo, omega-3FAs supplementation significantly increased FMD by 2.30%, at a dose ranging from 0.45 to 4.5 g/d over a median of 56 days. Subgroup analyses suggested that the effect of omega-3 FAs on FMD might be modified by the health status of the participants or the dose of supplementation. Sensitivity analyses indicated that the protective effect of omega-3 on endothelial function was robust. No significant change in EIV was observed after omega-3 FAs supplementation. Conclusion: Supplementation of omega-3 fatty acids significantly improves the endothelial function without affecting endothelium-independent dilation.
Circulating omega-3 polyunsaturated fatty acids and subclinical brain abnormalities on MRI in older adults: the cardiovascular health study.
Affiliation: University of Eastern Finland, Institute of Public Health and Clinical Nutrition, Kuopio, Finland.
Abstract: Consumption of tuna or other broiled or baked fish, but not fried fish, is associated with fewer subclinical brain abnormalities on magnetic resonance imaging (MRI). The authors investigated the association between plasma phospholipid omega-3 polyunsaturated fatty acids (PUFAs), objective biomarkers of exposure, and subclinical brain abnormalities on MRI. In the community-based Cardiovascular Health Study, 3660 participants aged ¡Ý 65 underwent brain MRI in 1992-1994, and 2313 were rescanned 5 years later. MRIs were centrally read by neuroradiologists in a standardized, blinded manner. Participants with recognized transient ischemic attacks or stroke were excluded. Phospholipid PUFAs were measured in stored plasma collected in 1992-1993 and related to cross-sectional and longitudinal MRI findings. After multivariable adjustment, the odds ratio for having a prevalent subclinical infarct was 0.60 in the highest versus lowest long-chain omega-3 PUFA quartile. Higher long-chain omega-3 PUFA content was also associated with better white matter grade, but not with sulcal or ventricular grades, markers of brain atrophy, or with incident subclinical infarcts. The phospholipid intermediate-chain omega-3 PUFA alpha-linolenic acid was associated only with modestly better sulcal and ventricular grades. However, this finding was not supported in the analyses with alpha-linolenic acid intake. Conclusion: Among older adults, higher phospholipid long-chain omega-3 PUFA content was associated with lower prevalence of subclinical infarcts and better white matter grade on MRI. The authors¡¯ results support the beneficial effects of fish consumption, the major source of long-chain omega-3 PUFAs, on brain health in later life.
Omega-3 fatty acid supplementation in adolescents with borderline personality disorder and ultra-high risk criteria for psychosis: a post hoc subgroup analysis of a double blind randomized controlled trial.
Affiliation: Department of Child and Adolescent Psychiatry, Medical University of Vienna, Vienna, Austria
Abstract: The objective was to investigate whether long-chain omega-3 (n-3) polyunsaturated fatty acids (PUFAs) improve functioning and psychiatric symptoms in young people with borderline personality disorder (BPD) who also meet ultra-high risk criteria for psychosis. The authors conducted a post hoc subgroup analysis of a double-blind, randomized controlled trial. Fifteen adolescents with BPD were randomized to either 1.2 g/day n-3 PUFAs or placebo. The intervention period was 12 weeks. Study measures included the Positive and Negative Syndrome Scale, the Montgomery-Åsberg Depression Rating Scale, and the Global Assessment of Functioning. Side effects were documented with the Udvalg for Kliniske Undersøgelser. Fatty acids in erythrocytes were analyzed using capillary gas chromatography. At baseline, erythrocyte n-3 PUFA levels correlated positively with psychosocial functioning and negatively with psychopathology. By the end of the intervention, n-3 PUFAs significantly improved functioning and reduced psychiatric symptoms, compared with placebo. Side effects did not differ between the treatment groups. Conclusion: Long-chain n-3 PUFAs should be further explored as a viable treatment strategy with minimal associated risk in young people with BPD.
Benefits of omega-3 fatty acid dietary supplementation on health-related quality of life in patients with meibomian gland dysfunction.
Affiliation: Department of Ophthalmology, Fundación Jiménez Díaz, Madrid, Spain.
Abstract: The researchers assessed the impact of a dietary supplement based on the combination of omega-3 essential fatty acids and antioxidants on health-related quality of life in patients with meibomian gland dysfunction (MGD). Patients of either sex (aged 18-85 years) diagnosed with MGD according to criteria identified at a 2011 International Workshop on Meibomian Gland Dysfunction participated in this randomized, double-masked, placebo-controlled study. Group A patients (controls) received an oral placebo supplement and group B patients received the oral study supplement. At baseline and at 3-month follow-up, the patients completed the 36-Item Short Form Health Survey questionnaire using a Spanish validated version. The Physical (PCS) and Mental (MCS) Component Summary scores were the main outcome variables. A total of 61 patients completed the study (group A, n=31; group B, n=30). There were no significant differences in PCS and MCS scores at baseline between the two study groups, but after 3 months of treatment, significantly higher mean PCS and MSC scores were observed in patients treated with the active omega-3 dietary supplement as compared with controls. Moreover, mean differences between values at 3 months as compared with baseline were statistically significant for patients in group B, whereas mean differences in patients assigned to group A were not statistically significant. Conclusion: Dietary supplementation with a combination of omega-3 essential fatty acids and antioxidants had a significant beneficial effect on HRQoL (health-related quality of life) in patients with MGD.