Clinical correlates and heritability of erythrocyte eicosapentaenoic and docosahexaenoic acid content in the Framingham Heart Study

Fish consumption and depression in Korean population: The Korea National Health and Nutrition Examination Survey, 2013-2021

BACKGROUND

Epidemiological studies in some populations showed that dietary intake of fish may be inversely associated with depression, but large studies in Korean population are limited. Thus, we investigated the association between fish consumption and depression, considering the serving size of fish, in Korean adults.

METHODS

This study was based on the data from the Korea National Health and Nutrition Examination Survey (2013-2021), which is a large nationally representative study of Korean population. Fish consumption was assessed with a 24-hour dietary recall, and physician-diagnosed depression status was assessed using questionnaires from the health interview survey. Multivariable logistic regression models adjusting for demographic, lifestyle, and dietary factors were used to calculate odds ratios (OR) and 95 % confidence intervals (CI) for depression.

RESULTS

A total of 31,632 adults aged 19-64 years were included in the analysis. After adjusting for covariates, highest fish consumption (≥4 servings/week) was significantly associated with 26 % lower odds of depression compared to the lowest fish consumption (<1 servings/week) (OR 0.74; 95 % CI, 0.60-0.92, P for trend = 0.007). A similar inverse association was found in female adults (OR 0.76; 95 % CI, 0.59-0.97, P for trend = 0.018), but no significant association was found in male adults (OR 0.75; 95 % CI, 0.49-1.15, P for trend = 0.223).

LIMITATIONS

Since KNHANES is a cross-sectional study, it is difficult to evaluate the causal relationship between fish consumption and depression risk.

CONCLUSIONS

This study results suggest that high fish consumption is associated with lower risk of depression in Korean adults, especially in female adults.

ω-3 Polyunsaturated Fatty Acid Status Testing in Humans: A Narrative Review of Commercially Available Options

There is an increasing body of evidence supporting a link between low intakes of ω-3 long-chain polyunsaturated fatty acids (LCPUFA) and numerous diseases and health conditions. However, few people are achieving the levels of fish/seafood or eicosapentaenoic acid and docosahexaenoic acid intake recommended in national and international guidelines. Knowledge of a person's ω-3 LCPUFA status will benefit the interpretation of research results and could be expected to lead to an increased effort to increase intake. Dietary intake survey methods are often used as a surrogate for measuring ω-3 PUFA tissue status and its impact on health and functional outcomes. However, because individuals vary widely in their ability to digest and absorb ω-3 PUFA, analytical testing of biological samples is desirable to accurately evaluate ω-3 PUFA status. Adipose tissue is the reference biospecimen for measuring tissue fatty acids, but less-invasive methods, such as measurements in whole blood or its components (e.g., plasma, serum, red blood cell membranes) or breast milk are often used. Numerous commercial laboratories provide fatty acid testing of blood and breast milk samples by different methods and present their results in a variety of reports such as a full fatty acid profile, ω-3 and ω-6 fatty acid profiles, fatty acid ratios, as well as the Omega-3 Index, the Holman Omega-3 Test, OmegaScore, and OmegaCheck, among others. This narrative review provides information about the different ways to measure ω-3 LCPUFA status (including both dietary assessments and selected commercially available analytical tests of blood and breast milk samples) and discusses evidence linking increased ω-3 LCPUFA intake or status to improved health, focusing on cardiovascular, neurological, pregnancy, and eye health, in support of recommendations to increase ω-3 LCPUFA intake and testing.

Effect of six month's treatment with omega-3 acid ethyl esters on long-term outcomes after acute myocardial infarction: The OMEGA-REMODEL randomized clinical trial

BACKGROUND

Omega-3 polyunsaturated fatty acids (O3-FA) have been shown to reduce inflammation and adverse cardiac remodeling after acute myocardial infarction (AMI). However, the impact of O3-FA on long-term clinical outcomes remains uncertain.

AIMS

To investigate the impact of O3-FA on adverse cardiac events in long-term follow up post AMI in a pilot-study.

METHODS

Consecutive patients with AMI were randomized 1:1 to receive 6 months of O3-FA (4 g/daily) or placebo in the prospective, multicenter OMEGA-REMODEL trial. Primary endpoint was a composite of major adverse cardiovascular events (MACE) encompassing all-cause death, heart failure hospitalizations, recurrent acute coronary syndrome, and late coronary artery bypass graft (CABG).

RESULTS

A total of 358 patients (62.8% male; 48.1 ± 16.1 years) were followed for a median of 6.6 (IQR: 5.0-9.1) years. Among those receiving O3-FA (n = 180), MACE occurred in 65 (36.1%) compared to 62 (34.8%) of 178 assigned to placebo. By intention-to-treat analysis, O3-FA treatment assignment did not reduce MACE (HR = 1.014; 95%CI = 0.716-1.436; p = 0.938), or its individual components. However, patients with a positive response to O3-FA treatment (n = 43), defined as an increase in the red blood cell omega-3 index (O3I) ≥5% after 6 months of treatment, had lower annualized MACE rates compared to those without (2.9% (95%CI = 1.2-5.1) vs 7.1% (95%CI = 5.7-8.9); p = 0.001). This treatment benefit persisted after adjustment for baseline characteristics (HRadjusted = 0.460; 95%CI = 0.218-0.970; p = 0.041).

CONCLUSION

In long-term follow-up of the OMEGA-REMODEL randomized trial, O3-FA did not reduce MACE after AMI by intention to treat principle, however, patients who achieved a ≥ 5% increase of O3I subsequent to treatment had favorable outcomes.

Fatty Acid Intake and Polyunsaturated Fatty Acid Biomarkers and Risk of Total Knee or Hip Arthroplasty Among Older Women in the Women's Health Initiative

OBJECTIVE

The objective was to determine whether baseline fatty acid intake and erythrocyte omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) can predict risk of total hip arthroplasty (THA) and total knee arthroplasty (TKA) in older women.

METHODS

This was a prospective analysis of 34,990 women in the Women's Health Initiative. Dietary fatty acids were estimated from food frequency questionnaires. Imputed erythrocyte PUFAs were available in a subcohort of 3,428 women. Arthroplasty (THA and TKA), used as a surrogate of severe osteoarthritis, was identified via linked Medicare data. Cox proportional hazards models were constructed to estimate risk of arthroplasty.

RESULTS

Risk of THA was associated with higher intake of arachidonic acid, (multivariable hazard ratio [HR] quartile 4 [Q4] vs Q1: 1.16; 95% confidence interval [CI] 1.01-1.34; P = 0.03) and higher intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA; HR Q4 vs Q1: 1.20; 95% CI 1.05-1.39; P = 0.003). There was a linear trend (P = 0.04) for patients to have a higher risk of THA with higher erythrocyte EPA and DHA in body mass index-adjusted models; however, there was no significant difference in patients who had THAs by quartiles of erythrocyte EPA and DHA (P = 0.10). Dietary fatty acids and erythrocyte PUFAs were not significantly associated with risk of TKA.

CONCLUSION

Higher baseline intakes of arachidonic acid and EPA and DHA were associated with a modestly higher risk of THA. No association was found between fatty acids and patients who had TKAs. Further research in populations with direct measures of osteoarthritis severity is needed to better understand the importance of PUFAs in modulating osteoarthritis and arthroplasty risk.

Very low Omega-3 Index in young healthy students from Palestine

Oily fish is rich in long-chain omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which have been associated with several health benefits. However, fish consumption is generally low in many countries, including the Middle East, resulting in low omega-3 blood levels. In Palestine, no data on the omega-3 blood status is available. The aim of this cross-sectional study was to assess the omega-3 status and related factors in young healthy subjects from Palestine. Omega-3 status was assessed using the Omega-3 Index-defined as the sum of EPA + DHA in relation to the total fatty acid content of erythrocytes. A total of 149 subjects, 50 males and 99 females (age range: 18-24 years), were included in the study. In addition to the Omega-3 Index, data on anthropometrics, physical activity, smoking status, fish intake, dietary supplement intake, blood lipid profile, and whole erythrocyte fatty acid pattern were collected. The mean (SD) Omega-3 Index was 2.56 (0.57)%, with 97.9% of subjects having an index below 4%. The majority of participants (91.8%) consumed less than two portions of fish per week, and only 4% reported taking omega-3 supplements, mostly irregularly. Our findings show that young Palestinian students have an alarmingly low omega-3 status. Further studies are needed to investigate whether the omega-3 status is also low in the general Palestinian population.

Nutritional factors associated with aggression

Although the vast majority of patients in forensic psychiatry are treated using pharmacological agents, clinical and ethical concerns about their use have led to the consideration of alternative strategies to reduce aggression that is common in forensic psychiatric settings. One non-invasive and benign biologically-based treatment approach involves nutrition. This article provides a mini-review of the recent evidence on four salient nutritional factors associated with aggressive behavior, namely omega-3 fatty acids, vitamin D, magnesium, and zinc. The current evidence base indicates that lower omega-3 levels are associated with increased aggression. Although research on vitamin D and zinc in relation to aggressive behavior is more limited, there is initial evidence that they are negatively associated with aggression in healthy participants and in psychiatric samples. The relationship between magnesium and aggression varies depending on how magnesium is assessed. Findings from experimental trials reveal that nutritional intervention in the form of omega-3 supplementation has the potential to serve as an effective mode of treatment, with effects that can last beyond the intervention period. There is also support for the utility of nutrition to improve our understanding of how social processes are linked to aggression. In light of the nascent, but promising findings on the role of nutritional factors on aggressive behavior, directions for future research are discussed.

Genome-wide association study of Red Blood Cell fatty acids in the Women's Health Initiative Memory Study

Despite their widespread associations with a wide variety of disease phenotypes, the genetics of red blood cell fatty acids remains understudied. We present one of the first genome-wide association studies of red blood cell fatty acid levels, using the Women's Health Initiative Memory study - a prospective cohort of N = 7,479 women aged 65-79. Approximately 9 million SNPs were measured directly or imputed and, in separate linear models adjusted for age and genetic principal components of ethnicity, SNPs were used to predict 28 different fatty acids. SNPs were considered genome-wide significant using a standard genome-wide significance level of p < 1 × 10-8. Twelve separate loci were identified, seven of which replicated results of a prior RBC-FA GWAS. Of the five novel loci, two have functional annotations directly related to fatty acids (ELOVL6 and ACSL6). While overall explained variation is low, the twelve loci identified provide strong evidence of direct relationships between these genes and fatty acid levels. Further studies are needed to establish and confirm the biological mechanisms by which these genes may directly contribute to fatty acid levels.

Higher n-3 polyunsaturated fatty acid status during early pregnancy is associated with lower risk for depression at 12 months postpartum: The NuPED study

Perinatal depression can negatively affect the health of the mother and her offspring. N-3 polyunsaturated fatty acids (PUFA) may play a role in the aetiology of depression. Therefore, we investigated the association of n-3 PUFA status during early pregnancy with perinatal depression among women living in urban Johannesburg, South Africa. For this prospective analysis, we analysed red blood cell (RBC) total phospholipid fatty acid (FA) composition (% of total FA) of 242 pregnant women at <18 weeks' gestation. We used the Edinburgh Postnatal Depression Scale (EPDS) to identify women at risk for depression (EPDS score ≥9) at <18, 22 and 36 weeks' gestation, and at 6 and 12 months postpartum. RBC EPA status was negatively (β=-0.22, p<0.05), and the AA/EPA ratio positively (β=0.24, p<0.05) associated with EPDS scores at 12 months postpartum. Higher RBC DHA and n-3 index were further associated with lower odds (OR=0.56 [95% CI: 0.32-0.91]; OR=0.63 [95% CI: 0.39-0.94]), while higher n-6/n-3 PUFA and AA/EPA ratios early in pregnancy were associated with higher odds for depression at 12 months postpartum ((OR=2.34 [95% CI: 1.12-4.97]; OR=1.02 [95% CI: 1.00-1.05]). Our results suggest that women with a higher RBC n-3 PUFA status during early pregnancy may be at lower risk for depression at 12 months postpartum.

The influence of dietary and supplemental omega-3 fatty acids on the omega-3 index: A scoping review

Introduction

The majority of the population do not consume adequate omega-3 fatty acids (n-3 FA), leading to global deficiencies, as evidenced by poor omega-3 status. An indicator of overall n-3 FA status, omega3-index (O3i) ≥8% has been associated with reduced risk of chronic disease, most notably cardiovascular disease. Thus, a synthesis of current research summarizing the effects of n-3 FA intake on O3i is warranted to develop and refine clinical recommendations. The purpose of this scoping review was to evaluate the effect of n-3 FA interventions and estimate sufficient n-3 FA intake to improve O3i to meet recommendations.

Methods

Search criteria were human studies published in English from 2004 to 2022 that assessed O3i at baseline and following an n-3 FA intervention.

Results

Fifty-eight studies that met inclusion criteria were identified. Protocols included fish consumption, fortified foods, combined eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplements, supplements of single n-3 FA (alpha linolenic acid (ALA), EPA, DHA, etc.), and supplements providing multiple n-3 FA. Dietary supplements varied in chemical composition; the most common were triglycerides or ethyl esters. The lowest supplementation protocol was 100 mg/d, and the largest was 4,400 mg/d EPA and DHA. Supplementation time period ranged from 3 weeks to 1 year. At baseline, three study samples had mean O3i >8%, although many intervention protocols successfully increased O3i.

Discussion

Generally, the lowest doses shown to be effective in raising O3i to recommended levels were >1,000 mg/d of combination DHA plus EPA for 12 weeks or longer. Supplements composed of triglycerides were more bioavailable and thus more effective than other formulas. Based on the data evaluated, practical recommendations to improve O3i to ≥8% are consumption of 1,000-1,500 mg/d EPA plus DHA as triglycerides for at least 12 weeks.

The Fish Oil to Reduce Tobacco Use iN Expectant mothers (FORTUNE) feasibility trial

BACKGROUND

Three small clinical trials have suggested that supplementation with n-3 long-chain polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid) found in fish oils may reduce nicotine cravings and at higher doses reduce cigarette consumption. Pregnant women who smoke have fewer pharmacologic options to aid them with smoking cessation. Although n-3 long-chain polyunsaturated fatty acid supplementation has been studied in pregnancy, few studies have evaluated doses of ≥4 g per day, and no previous studies have selectively enrolled pregnant women who smoke. High-dose n-3 long-chain polyunsaturated fatty acids may aid cessation but could be poorly tolerated in pregnant women who smoke because of gastrointestinal side effects.

OBJECTIVE

We conducted a feasibility trial to determine the tolerability of high-dose n-3 long-chain polyunsaturated fatty acid supplementation in pregnant women who smoked. We hypothesized that n-3 long-chain polyunsaturated fatty acid doses of 4.2 g a day would be well-tolerated relative to an olive oil placebo. We assessed red blood cell phospholipid membrane concentrations at baseline and end of therapy (4 weeks) and piloted outcomes for a future efficacy trial of n-3 long-chain polyunsaturated fatty acid supplementation for smoking cessation in pregnancy.

STUDY DESIGN

We recruited 28 pregnant women between the gestational ages of 6 and 36 weeks who reported daily cigarette smoking and were motivated to quit to participate in a double-blind placebo-controlled randomized feasibility trial of 4.2 g per day of n-3 long-chain polyunsaturated fatty acid supplementation. Participants reported cigarettes per day, completed the Fagerström Test for Cigarette Dependence, and provided blood, urine, and exhaled CO samples. We used repeated-measures analysis of variance to pilot analyses of changes in cigarettes per day and Fagerström Test for Cigarette Dependence scores.

RESULTS

At baseline, red blood cell membrane eicosapentaenoic acid concentrations were negatively correlated with cigarettes per day (r=-0.44; P=.04). By 4 weeks, circulating n-3 long-chain polyunsaturated fatty acid levels increased by 18% in the n-3 long-chain polyunsaturated fatty acid supplementation arm vs a decrease of 3% in the placebo arm. Occurrence of gastrointestinal side effects such as burping, heartburn, diarrhea, abdominal pain, or nausea did not differ statistically between study arms. At 4 weeks, participants allocated to the n-3 long-chain polyunsaturated fatty acids arm reported a median of 3 cigarettes per day (interquartile range, 1-8) vs 7 cigarettes per day (interquartile range, 1-14) in the placebo arm, which was not statistically significant (P=.99). Participants allocated to the n-3 long-chain polyunsaturated fatty acids arm had a decrease of 1 (interquartile range, 0-1) on the Fagerström Test for Cigarette Dependence score vs 0 (interquartile range, 0-0) for placebo (P=.46).

CONCLUSION

High-dose n-3 long-chain polyunsaturated fatty acids may be tolerated in pregnant women who smoke; however, there was a high level of participant dropout, with more participants allocated to the fish oil arm becoming lost to follow-up. These results will inform the design of a future large-scale randomized controlled trial to test the impact of fish oil supplements on smoking cessation in pregnancy.

Assessing Omega-3 Intake in Sport: the Brief Food Frequency Questionnaire and the Omega-3 Index in Collegiate Women Soccer Players

CONTEXT

Omega-3 fatty acids modulate inflammatory processes and are considered beneficial for sport populations, highlighting a need to assess omega-3 intake in a practical manner. Food frequency questionnaires (FFQs) are inexpensive, noninvasive tools aimed at evaluating nutrient intakes such as omega-3 fatty acids. In healthy adults, a tailored, brief FFQ for estimating omega-3 intake was associated with the erythrocyte omega-3 fatty acid level, a biomarker for omega-3 tissue status and indicative of intake. However, the association between a brief omega-3 FFQ and erythrocyte levels, particularly the Omega-3 Index (eicosapentaenoic acid [EPA], docosahexaenoic acid [DHA], and EPA + DHA), has yet to be explored in a sport population.

OBJECTIVE

To examine the association between omega-3 intake using a brief FFQ and the Omega-3 Index in collegiate women soccer players.

DESIGN

Cross-sectional study.

SETTING

University sport team.

PATIENTS OR OTHER PARTICIPANTS

Thirty-one National Collegiate Athletic Association Division I collegiate women soccer players.

MAIN OUTCOME MEASURE(S)

The brief omega-3 FFQ assessed dietary omega-3 intake: DHA and EPA. The OmegaQuant blood test measured erythrocyte omega-3 fatty acid (EPA, DHA) and Omega-3 Index (EPA + DHA) levels.

RESULTS

Brief FFQ intakes of EPA, DHA, and EPA + DHA were positively correlated with the erythrocyte EPA (r = 0.48, P = .007), DHA (r = 0.73, P < .001), and Omega-3 Index (r = 0.73, P < .001).

CONCLUSIONS

In a sample of collegiate women soccer players, the brief omega-3 FFQ was correlated with erythrocyte omega-3 fatty acid levels and may offer health practitioners a practical tool for assessing omega-3 intake in this collegiate sport population.

Association between Omega-3 Index and Hyperglycemia Depending on Body Mass Index among Adults in the United States

There is inconsistency regarding the association between long-chain n-3 polyunsaturated fatty acids such as eicosapentaenoic acid (EPA; 20:5n3) and docosahexaenoic acid (DHA; 22:6n3) and the risk of type 2 diabetes. The present study aimed to investigate the association between the Omega-3 Index (erythrocyte EPA + DHA) and glycemic status as a function of body mass index (BMI). Cross-sectional data from routine clinical laboratory testing with a total of 100,572 people aged over 18 years and BMI ≥ 18.5 kg/m² were included. Of the patients, 10% were hyperglycemic (fasting plasma glucose levels ≥ 126 mg/dL) and 24.7% were of normal weight, 35.0% were overweight, and 40.3% were obese. Odds ratios (ORs) of being hyperglycemic were inversely associated with the Omega-3 Index, but weakened as BMI increased. Thus, ORs (95% CI) comparing quintile 5 with quintile 1 were 0.54 (0.44-0.66) in the normal weight group, 0.70 (0.61-0.79) in the overweight group, and 0.74 (0.67-0.81) in the obese group. Similar patterns were seen for EPA and DHA separately. The present study suggested that a low Omega-3 Index is associated with a greater risk of disordered glucose metabolism and this is independent of BMI.

Plasma Gut Microbe-Derived Metabolites Associated with Peripheral Artery Disease and Major Adverse Cardiac Events

Cardiovascular diseases are associated with gut dysbiosis, but the role of microbe-derived metabolites as biomarkers or modulators of cardiovascular disease are not well understood. This is a targeted metabolomics study to investigate the association of nine microbe-derived metabolites with lower extremity peripheral artery disease (PAD), a form of atherosclerosis, and major adverse cardiac events (MACE). The study cohort consists of individuals with intermittent claudication and ankle-brachial index (ABI) < 0.9 (N = 119) and controls without clinically-apparent atherosclerosis (N = 37). The primary endpoint was MACE, a composite endpoint of myocardial infarction, coronary revascularization, stroke, transient ischemic attack, or cardiac-related death. Plasma metabolite concentrations differed significantly between the PAD and control groups. After adjustment for traditional atherosclerosis risk factors, kynurenine, hippuric acid, indole-3-propionic acid (IPA), and indole-3-aldehyde (I3A) concentrations were negatively associated with PAD, whereas indoxyl sulfate and 3-hydroxyanthranilic acid were positively associated. Hippuric acid, IPA, and I3A correlated with ABI, a surrogate for atherosclerotic disease burden. Those in the highest I3A concentration quartile had significantly improved freedom from MACE during follow-up compared to those in the lowest quartile. This study identifies specific indole- and phenyl-derived species impacted by gut microbial metabolic pathways that could represent novel microbiome-related biomarkers of PAD.

Estimation and predictors of the Omega-3 Index in the UK Biobank

Information on the Omega-3 Index (O3I) in the United Kingdom (UK) are scarce. The UK-Biobank (UKBB) contains data on total plasma omega-3 polyunsaturated fatty acids (n3-PUFA%) and DHA% measured by NMR. The aim of our study was to create an equation to estimate the O3I (eO3I) from these data. We first performed an interlaboratory experiment with 250 random blood samples in which the O3I was measured in erythrocytes by gas chromatography, and total n3% and DHA% were measured in plasma by NMR. The best predictor of eO3I included both DHA% and a derived metric, the total n3%-DHA%. Together these explained 65% of the variability (r=0.832, p<0.0001). We then estimated the O3I in 117,108 UKBB subjects and correlated it with demographic and lifestyle variables in multivariable adjusted models. The mean (SD) eO3I was 5.58% (2.35%) this UKBB cohort. Several predictors were significantly correlated with eO3I (all p<0.0001). In general order of impact and with directionality (- = inverse, + = direct): oily-fish consumption (+), fish oil supplement use (+), female sex (+), older age (+), alcohol use (+), smoking (-), higher waist circumference and BMI (-), lower socioeconomic status and less education (-). Only 20.5% of eO3I variability could be explained by predictors investigated, and oily-fish consumption accounted for 7.0% of that. With the availability of the eO3I in the UKBB cohort we will be in a position to link risk for a variety of diseases with this commonly-used and well-documented marker of n3-PUFA biostatus.

Genes regulating levels of ω-3 long-chain polyunsaturated fatty acids are associated with alcohol use disorder and consumption, and broader externalizing behavior in humans

BACKGROUND

Individual variation in the physiological response to alcohol is predictive of an individual's likelihood to develop alcohol use disorder (AUD). Evidence from diverse model organisms indicates that the levels of long-chain polyunsaturated omega-3 fatty acids (ω-3 LC-PUFAs) can modulate the behavioral response to ethanol and therefore may impact the propensity to develop AUD. While most ω-3 LC-PUFAs come from diet, humans can produce these fatty acids from shorter chain precursors through a series of enzymatic steps. Natural variation in the genes encoding these enzymes has been shown to affect ω-3 LC-PUFA levels. We hypothesized that variation in these genes could contribute to the susceptibility to develop AUD.

METHODS

We identified nine genes (FADS1, FADS2, FADS3, ELOVL2, GCKR, ELOVL1, ACOX1, APOE, and PPARA) that are required to generate ω-3 LC-PUFAs and/or have been shown or predicted to affect ω-3 LC-PUFA levels. Using both set-based and gene-based analyses we examined their association with AUD and two AUD-related phenotypes, alcohol consumption, and an externalizing phenotype.

RESULTS

We found that the set of nine genes is associated with all three phenotypes. When examined individually, GCKR, FADS2, and ACOX1 showed significant association signals with alcohol consumption. GCKR was significantly associated with AUD. ELOVL1 and APOE were associated with externalizing.

CONCLUSIONS

Taken together with observations that dietary ω-3 LC-PUFAs can affect ethanol-related phenotypes, this work suggests that these fatty acids provide a link between the environmental and genetic influences on the risk of developing AUD.

Maternal erythrocyte fatty acid composition as a predictive marker for pregnancy health

Pregnancy is accompanied by a surge in demand for fatty acids (FAs) in order to support maternal health, as well as fetal growth and development. Of particular demand is essential for long-chain polyunsaturated FAs. FAs are primarily obtained from dietary sources and are distributed in the body. In comparison with the use of self-reporting approaches, measuring the FA levels within different blood compartments can present a more accurate image of nutritional, and thus tissue, FA composition. Hence, the FA profile of plasma or serum is commonly used for physiological analyses. Nevertheless, plasma and serum FAs are not yet incorporated into cell membranes, and consequently may not be a suitable reflection of the FA status of body tissues. The evaluation of erythrocyte FA levels offers a superior possibility for the following reasons: the biological fluctuation of erythrocyte FA composition is low, phospholipids account for almost all the lipid content of erythrocytes, and the FA profiles of erythrocytes represent those of tissues. Here, we elaborate on whether the status of maternal erythrocyte FAs can serve as a prognostic biomarker for reproductive health and fetomaternal complications, including embryonic and fetoplacental development, gestational length, and preeclampsia. In addition, factors with the potential of altering the maternal erythrocyte FAs such as maternal diet, lifestyle habits, genetics, and body composition are discussed.

Red blood cell fatty acid patterns from 7 countries: Focus on the Omega-3 index

Red blood cell (RBC) fatty acid (FA) patterns are becoming recognized as long-term biomarkers of tissue FA composition, but different analytical methods have complicated inter-study and international comparisons. Here we report RBC FA data, with a focus on the Omega-3 Index (EPA + DHA in% of total FAs in RBC), from samples of seven countries (USA, Canada, Italy, Spain, Germany, South Korea, and Japan) including 167,347 individuals (93% of all samples were from the US). FA data were generated by a uniform methodology from a variety of interventional and observational studies and from clinical laboratories. The cohorts differed in size, demographics, health status, and year of collection. Only the Canadian cohort was a formal, representative population-based survey. The mean Omega-3 Index of each country was categorized as desirable (>8%), moderate (>6% to 8%), low (>4% to 6%), or very low (≤4%). Only cohorts from Alaska (treated separately from the US), South Korea and Japan showed a desirable Omega-3 Index. The Spanish cohort had a moderate Omega-3 Index, while cohorts from the US, Canada, Italy, and Germany were all classified as low. This study is limited by the use of cohorts of convenience and small sample sizes in some countries. Countries undertaking national health status studies should utilize a uniform method to measure Omega-3 FA levels.

Investigating N-3 Fatty Acids to prevent Neonatal Tobacco-related outcomeS (INFANTS): study protocol for a double-blind, randomized, placebo-controlled parallel clinical trial of n-3 polyunsaturated fatty acids in pregnant smokers

BACKGROUND

Tobacco use during pregnancy is the most important modifiable risk factor associated with adverse pregnancy outcomes, increasing the risk of preterm birth, intrauterine growth restriction and sudden infant death syndrome. Fewer than half of pregnant smokers can quit on their own. Identifying safe and effective therapies to prevent tobacco-related adverse pregnancy outcomes and/or increase smoking cessation in pregnant women would have a substantial public health impact. Cigarette smoking is associated with a relative deficiency in circulating n-3 long-chain polyunsaturated fatty acid (n-3 LCPUFA) levels. A recent analysis found that smokers taking n-3 LCPUFAs during pregnancy had a reduction in preterm labor risk when compared to non-smokers. Studies have shown that supplemental n-3 LCPUFAs may also reduce nicotine cravings and daily cigarette use. Thus, smokers may benefit from supplemental n-3 LCPUFAs by lowering the risk of preterm labor and/or increased smoking cessation. To address important remaining knowledge gaps, we propose the Investigating N-3 Fatty Acids to prevent Neonatal Tobacco related outcomeS (INFANTS).

METHODS

The INFANTS study is a multicenter, randomized, double-blind, placebo-controlled study that will randomize 400 pregnant smokers to either supplemental n-3 LCPUFAs or placebo. Participants will be enrolled between 12 and 24 weeks' gestation and followed until 6 weeks after delivery. We will recruit from clinical centers throughout Middle Tennessee. We will assess smoking behavior after 12 weeks of supplementation using self-report and validated biomarkers of tobacco exposure. We will measure response to supplementation using biological markers of n-3 LCPUFA status. Our primary endpoint will be preterm labor as reflected by gestational age at delivery. Our secondary endpoint will be change from baseline in cigarettes per day at 12 weeks.

DISCUSSION

This study tests the hypothesis that smoking-induced n-3 LCPUFA deficiencies contribute to tobacco-related adverse pregnancy outcomes and that supplementation of n-3 LCPUFAs in pregnant smokers may prevent these complications. If our study demonstrates that supplemental n-3 LCPUFAs are effective at reducing the risk of tobacco-related adverse neonatal outcomes and/or reducing tobacco use during pregnancy, our results could have an immediate and major impact on pregnancy care and neonatal outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04417595. Registered on April 21, 2020.

Dietary Control of Inflammation and Resolution

The healing of any injury requires a dynamic balance of initiation and resolution of inflammation. This hypothesis-generating review presents an overview of the various nutrients that can act as signaling agents to modify the metabolic responses essential for the optimal healing of injury-induced inflammation. In this hypothesis-generating review, we describe a defined nutritional program consisting of an integrated interaction of a calorie-restricted anti-inflammatory diet coupled with adequate levels of omega-3 fatty acids and sufficient levels of dietary polyphenols that can be used in clinical trials to treat conditions associated with insulin resistance. Each dietary intervention works in an orchestrated systems-based approach to reduce, resolve, and repair the tissue damage caused by any inflammation-inducing injury. The orchestration of these specific nutrients and their signaling metabolites to facilitate healing is termed the Resolution Response. The final stage of the Resolution Response is the activation of intracellular 5' adenosine monophosphate-activated protein kinase (AMPK), which is necessary to repair tissue damaged by the initial injury-induced inflammation. The dietary optimization of the Resolution Response can be personalized to the individual by using standard blood markers. Once each of those markers is in their appropriate ranges, activation of intracellular AMPK will be facilitated. Finally, we outline how the resulting activation of AMPK will affect a diverse number of other intercellular signaling systems leading to an extended healthspan.

Evaluation of Omega-3 Status in Professional Basketball Players

ABSTRACT

Davis, JK, Freese, EC, Wolfe, AS, Basham, SA, and Stein, KMW. Evaluation of omega-3 status in professional basketball players. J Strength Cond Res 35(7): 1794-1799, 2021-Omega-3 polyunsaturated fatty acids (PUFA) has been shown to promote muscle remodeling, improve immune status, decrease muscle soreness, and help maintain explosive power. Research that has assessed omega-3 blood concentrations with athletes has primarily focused on the college athlete. However, limited work has been conducted with the professional athlete. Therefore, the purpose of this study was to evaluate the omega-3 PUFA blood concentrations, dietary, and supplement intake of professional basketball players. Blood collection occurred during preseason medical screenings and analyzed for eicosapentaenoic acid, docosahexaenoic acid, the omega-3 Index (O3i), and various fatty acids using dried blood spot sampling. The mean O3i of 119 professional basketball players was 5.02 + 1.19% (range, 2.84-9.76%). Dietary intake of players showed that 31% of players reported consuming no fish in their diet per week, with 61% of players reported consuming less than 2 servings of fish per week. Only 12 of the 119 players reported supplementing with omega-3 PUFA, which varied widely for dosage and frequency of supplementation. A moderate correlation was shown for O3i and dietary fish consumption per week (r = 0.58; p < 0.01) and fish consumption per month (r = 0.57; p < 0.01). A large number of players reported consuming less than the recommend amount of dietary fish per week and very few players reported supplementing with omega-3 PUFA. The low intake of omega-3 PUFA likely contributed, in part, to the majority of players having an O3i of less than 8%.

Using an erythrocyte fatty acid fingerprint to predict risk of all-cause mortality: the Framingham Offspring Cohort

BACKGROUND

RBC long-chain omega-3 (n-3) fatty acid (FA) percentages (of total fatty acids) are associated with lower risk for total mortality, but it is unknown if a suite of FAs could improve risk prediction.

OBJECTIVES

The objective of this study was to compare a combination of RBC FA levels with standard risk factors for cardiovascular disease (CVD) in predicting risk of all-cause mortality.

METHODS

Framingham Offspring Cohort participants without prevalent CVD having RBC FA measurements and relevant baseline clinical covariates (n = 2240) were evaluated during 11 y of follow-up. A forward, stepwise approach was used to systematically evaluate the association of 8 standard risk factors (age, sex, total cholesterol, HDL cholesterol, hypertension treatment, systolic blood pressure, smoking status, and prevalent diabetes) and 28 FA metrics with all-cause mortality. A 10-fold cross-validation process was used to build and validate models adjusted for age and sex.

RESULTS

Four of 28 FA metrics [14:0, 16:1n-7, 22:0, and omega-3 index (O3I; 20:5n-3 + 22:6n-3)] appeared in ≥5 of the discovery models as significant predictors of all-cause mortality. In age- and sex-adjusted models, a model with 4 FA metrics was at least as good at predicting all-cause mortality as a model including the remaining 6 standard risk factors (C-statistic: 0.778; 95% CI: 0.759, 0.797; compared with C-statistic: 0.777; 95% CI: 0.753, 0.802). A model with 4 FA metrics plus smoking and diabetes (FA + Sm + D) had a higher C-statistic (0.790; 95% CI: 0.770, 0.811) compared with the FA (P < 0.01) or Sm + D models alone (C-statistic: 0.766; 95% CI: 0.739, 0.794; P < 0.001). A variety of other highly correlated FAs could be substituted for 14:0, 16:1n-7, 22:0, or O3I with similar predicted outcomes.

CONCLUSIONS

In this community-based population in their mid-60s, RBC FA patterns were as predictive of risk for death during the next 11 y as standard risk factors. Replication is needed in other cohorts to validate this FA fingerprint as a predictor of all-cause mortality.

Aspirin and omega-3 fatty acid status interact in the prevention of cardiovascular diseases in Framingham Heart Study

BACKGROUND

The roles of omega-3 (n3) fatty acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] and low-dose aspirin in the primary prevention of ischemic cardiovascular disease (CVD) are controversial. Since omega-3 (n3) fatty acids and aspirin affect cyclooxygenase activity in platelets, there could be a clinically-relevant effect of aspirin combined with a particular n3 fatty acid level present in each individual.

METHODS

RBC EPA+DHA, arachidonic acid (AA) and docosapentaenoic acid (DPA) were measured in 2500 participants without known CVD in the Framingham Heart Study. We then tested for interactions with reported aspirin use (1004 reported use and 1494 did not) on CVD outcomes. The median follow-up was 7.2 years.

RESULTS

Having RBC EPA+DHA in the second quintile (4.2-4.9% of total fatty acids) was associated with significantly reduced risk for future CVD events (relative to the first quintile, <4.2%) in those who did not take aspirin (HR 0.54 (0.30, 0.98)), but in those reporting aspirin use, risk was significantly increased (HR 2.16 (1.19, 3.92)) in this quintile. This interaction remained significant when adjusting for confounders. Significant interactions were also present for coronary heart disease and stroke outcomes using the same quintiles. Similar findings were present for EPA and DHA alone but not for DPA and AA.

CONCLUSIONS

There is a complex interaction between aspirin use and RBC EPA+DHA levels on CVD outcomes. This suggests that aspirin use may be beneficial in one omega-3 environment but harmful in another, implying that a personalized approach to both aspirin use and omega-3 supplementation may be needed.

Proportions of long-chain ω-3 fatty acids in erythrocyte membranes of Canadian adults: Results from the Canadian Health Measures Survey 2012-2015

BACKGROUND

The Omega-3 Index (OI) is a proposed marker of coronary artery disease (CAD) risk. Another index, the EPA/arachidonic acid (AA) ratio has also been proposed as a possible risk marker for CAD.

OBJECTIVE

Our primary objective was to characterize the Canadian population subgroups that have an undesirable OI (<4%, associated with high CAD risk) and to identify the participants' characteristics most strongly associated with the OI. Our secondary objective was to identify the characteristics most strongly associated with the EPA/AA ratio.

DESIGN

Data from 4025 adult participants of cycles 3 and 4 (2012-2015) of the cross-sectional Canadian Health Measures Survey were pooled. Adjusted mean proportions of erythrocyte membrane ω-3 (n-3) fatty acids, total ω-6 fatty acids, and ratios were analyzed by sociodemographic, health, and lifestyle characteristics using covariate-adjusted models.

RESULTS

The mean OI was 4.5%. Almost 40% of Canadians had an undesirable (<4%) OI. ω-3 supplement use, fish intake, and race were the variables most strongly associated with OI scores. The prevalence of undesirable OI was significantly higher among participants consuming fish less than twice a week (43.8%; 95% CI: 39.0%, 48.6%) than among those consuming more fish (12.7%; 95% CI: 7.8%, 19.9%), among smokers (62.7%; 95% CI: 52.9%, 71.7%) than nonsmokers (33.4%; 95% CI: 29.4%, 37.7%), in whites (42.7%; 95% CI: 38.2%, 47.4%) than in Asians (23.0%; 95% CI: 15.4%, 33.0%), and in adults aged 20-39 y (49.6%; 95% CI: 42.3%, 56.9%) than in those aged 60-79 y (24.4%; 95% CI: 21.0%, 28.1%). ω-3 supplement intake and fish intake were the characteristics most strongly associated with EPA/AA. All P ≤ 0.05.

CONCLUSIONS

An important proportion of Canadian adults has an undesirable (<4%) OI, with higher prevalence in some subgroups. Further assessment is required to determine the value and feasibility of an increase in the population's OI to the currently proposed target of ≥8% as a potential public health objective.

Role of n-3 long-chain polyunsaturated fatty acids in human nutrition and health: review of recent studies and recommendations

Long-chain (LC) n-3 polyunsaturated fatty acids (n-3 PUFAs), in particular docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are nutrients involved in many metabolic and physiological processes, and are referred to as n-3 LCPUFA. They have been extensively studied for their effects in human nutrition and health. This paper provides an overview on metabolism, sources, dietary intake, and status of n-3 LCPUFA. A summary of the dietary recommendations for n-3 LCPUFAs for different age groups as well as specific physiological conditions is provided. Evidence for n-3 LCPUFA in cardiovascular diseases, including new studies, is reviewed. Expert recommendations generally support a beneficial effect of n-3 LCPUFA on cardiovascular health and recommend a daily intake of 500 mg as DHA and EPA, or 1-2 servings of fish per week. The role of n-3 LCPUFA on brain health, in particular neurodegenerative disorders and depression, is reviewed. The evidence for beneficial effects of n-3 LCPUFA on neurodegenerative disorders is non-conclusive despite mechanistic support and observational data. Hence, no definite n-3 LCPUFA expert recommendations are made. Data for the beneficial effect of n-3 LCPUFA on depression are generally compelling. Expert recommendations have been established: 200-300 mg/day for depression; up to 1-2 g/day for major depressive disorder. Recent studies support a beneficial role of n-3 LCPUFAs in reducing the risk for premature birth, with a daily intake of 600-800 mg of DHA during pregnancy. Finally, international experts recently reviewed the scientific evidence on DHA and arachidonic acid (ARA) in infant nutrition and concluded that the totality of data support that infant and follow-on formulas should provide both DHA and ARA at levels similar to those in breast milk. In conclusion, the available scientific data support that dietary recommendations for n-3 LCPUFA should be established for the general population and for subjects with specific physiological conditions.

Effects of menopausal hormone therapy on erythrocyte n-3 and n-6 PUFA concentrations in the Women's Health Initiative randomized trial

BACKGROUND

The factors other than dietary intake that determine tissue concentrations of EPA and DHA remain obscure. Prior studies suggested that, in women, endogenous estrogen may accelerate synthesis of DHA from ɑ-linolenic acid (ALA), but the effects of exogenous estrogen on RBC n-3 (ɷ-3) PUFA concentrations are unknown.

OBJECTIVE

We tested the hypothesis that menopausal hormone therapy (HT) would increase RBC n-3 PUFA concentrations.

METHODS

Postmenopausal women (ages 50-79 y) were assigned to HT or placebo in the Women's Health Initiative (WHI) randomized trial. The present analyses included a subset of 1170 women (ages 65-79 y) who had RBC PUFA concentrations measured at baseline and at 1 y as participants in the WHI Memory Study. HT included conjugated equine estrogens (E) alone for women without a uterus (n = 560) and E plus medroxyprogesterone acetate (P) for those with an intact uterus (n = 610). RBC n-3 and n-6 (ɷ-6) PUFAs were quantified.

RESULTS

Effects of E alone and E+P on PUFA profiles were similar and were thus combined in the analyses. Relative to the changes in the placebo group after 1 y of HT, docosapentaenoic acid (DPA; n-3) concentrations decreased by 10% (95% CI: 7.3%, 12.5%), whereas DHA increased by 11% (95% CI: 7.4%, 13.9%) in the HT group. Like DHA, DPA n-6 increased by 13% from baseline (95% CI: 10.0%, 20.3%), whereas linoleic acid decreased by 2.0% (95% CI: 1.0%, 4.1%; P values at least <0.01 for all). EPA and arachidonic acid concentrations were unchanged.

CONCLUSIONS

HT increased RBC concentrations of the terminal n-3 and n-6 PUFAs (DHA and DPA n-6). These findings are consistent with an estrogen-induced increase in DHA and DPA n-6 synthesis, which is consistent with an upregulation of fatty acid elongases and/or desaturases in the PUFA synthetic pathway. The clinical implications of these changes require further study. The Women's Health Initiative Memory Study is registered at clinicaltrials.gov as NCT00685009. Note that the data presented here were not planned as part of the original trial, and therefore are to be considered exploratory.

Interactive Effects of Omega-3 Polyunsaturated Fatty Acids and Secondhand Smoke in Mice and Human Subjects

Active smoking and secondhand smoke (SHS) exposure increase the risk of cardiovascular morbidity and mortality. Active smoking is associated with reduced levels of omega-3 polyunsaturated fatty acids (n-3 PUFA) and studies show that n-3 PUFA supplementation can improve smoking-induced vascular dysfunction. However, the relationship between n-3 PUFA and SHS exposure has not been studied. Fat-1 transgenic mice, which convert n-6 to n-3 PUFA, were fed diets with n-3 PUFA or without (n-6 PUFA diet), exposed to air or SHS for 4 weeks, and vasoreactivity, antioxidant indices, and omega-3 index (percent eicosapentaenoic + docosahexaenoic acids in RBC) measured. Compared to air-exposed mice, SHS-enhanced aortic constriction in mice fed the n-6 PUFA diet (omega-3 index, 5.9 ± 0.2%; mean ± SE), but not in mice fed the n-3 PUFA diet (omega-3 index, 7.8 ± 0.6%). SHS also significantly induced mRNA expression of cytochrome P4501A1, NADPH:quinone oxidoreductase, heme oxygenase-1, and angiotensinogen in adipose tissue, and increased antioxidant capacity only in mice on the n-6 PUFA diet. Notably, SHS reduced the omega-3 index by 1.0 percentage point (p = 0.003), compared to air-exposed mice irrespective of diet. Additionally, we recruited human nonsmokers (NS) with and without SHS exposure (n = 40) 19-40 years old and measured the omega-3 index and antioxidant capacity. In human subjects SHS exposure was associated with a significantly lower omega-3 index (NS, 4.4 ± 1.1%; NS + SHS, 3.2 ± 1.0%; mean ± SD, p = 0.002) and higher antioxidant capacity (p < 0.001) than unexposed NS. Thus, SHS exposure is associated with lower levels of n-3 PUFA in mice and humans; however, an omega-3 index of ~ 8% in mice has vasoprotective and antioxidant properties.

Higher omega-3 index is associated with more rapid heart rate recovery in healthy men and women

BACKGROUND

Previous studies have suggested that omega-3 polyunsaturated fatty acids (n-3 PUFA) can favorably influence cardiac autonomic tone. However, data regarding n-3 PUFA status and heart rate recovery (HRR) in healthy adults are sparse.

PURPOSE

To examine the association between n-3 PUFA status and HRR.

METHODS

Participants included 13,912 patients who underwent a comprehensive examination at the Cooper Clinic, Dallas TX. Fitness was determined from a maximal exercise test. HRR was calculated by subtracting the heart rate at 1, 3, and 5 min of an active recovery period from the maximal heart rate. Participants were categorized as having a low (<4%), normal (4-8%) or optimal (>8%) Omega-3 Index (O3I) (i.e., erythrocyte levels of eicosapentaenoic and docosahexaenoic acids). Multiple linear regression was used to model the association between O3I and HRR adjusting for age, maximal METs, body mass index, and smoking by sex.

RESULTS

Higher categories of O3I were associated with greater HRR at 1 min (men: 23.7, 23.9, 24.6 beats/min; women: 23.9, 24.6, 25.9 and 3 min (men: 52.4, 52.9, 53.6 beats/min; women: 51.9, 53.4, 54.6), p trend <0.01 for all. Corresponding HRR at 5 min were (men: 60.0, 60.2, 60.7 beats/min, p trend=0.09; women: 59.4, 60.8, 61.6, p trend <0.001). The HRR gradients across O3I categories were steeper in women than men at 1, 3, and 5 min (p<0.03 for all sex x O3I category interactions with HRR).

CONCLUSIONS

A direct relationship between HRR and O3I values was observed in both men and women, with a steeper gradient in women. These findings suggest a potential cardioprotective mechanism for n-3 PUFA.

Genetic variants in FADS1 and ELOVL2 increase level of arachidonic acid and the risk of Alzheimer's disease in the Tunisian population

Polyunsaturated fatty acids (PUFAs) are closely related to various physiological conditions. In several age-related diseases including Alzheimer's disease (AD) altered PUFAs metabolism has been reported. However, the mechanism behind PUFAs impairment and AD developpement remains unclear. In humans, PUFAs biosynthesis requires delta-5 desaturase (D5D), delta-6 desaturase (D6D) and elongase 2 activities; which are encoded by fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2), and elongation of very-long-chain fatty acids-like 2 (ELOVL2) genes, respectively. In the present work, we aim to assess whether genetic variants in FADS1, FADS2 and ELOVL2 genes influence plasma and erythrocyte PUFA composition and AD risk. A case-control study was carried out in 113 AD patients and 161 healthy controls.Rs174556, rs174617, and rs3756963 of FADS1, FADS2, and ELOVL2 genes, respectively were genotyped using PCR-RFLP. PUFA levels were quantified using Gas Chromatography. Genotype distributions of rs174556 (FADS1) and rs3756963 (ELOVL2) were different between case and control groups. The genotype TT of rs174556 and rs3756963 single nucleotide polymorphism (SNP) increases significantly the risk of AD in our population. PUFA analysis showed higher plasma and erythrocyte arachidonic acid (AA) level in patients with AD, whereas only plasma docosahexaenoic acid (DHA) was significantly decreased in AD patients. The indexes AA/Dihomo-gamma-linolenic acid (DGLA) and C24:4n-6/Adrenic acid (AdA) were both higher in the AD group. Interestingly, patients with TT genotype of rs174556 presented higher AA level and AA/DGLA index in both plasma and erythrocyte. In addition, higher AA and AA/DGLA index were observed in erythrocyte of TT genotype ofrs3756963 carrier's patients. Along with, positive correlation between AA/DGLA index, age or Gamma-linolenic acid (GLA)/ Linoleic acid (LA) index was seen in erythrocyte and /or plasma of AD patients. After adjustment for confounding factors, the genotype TT of rs174556, erythrocyte AA and AA/DGLA index were found to be predictive risk factors for AD while plasma DHA was found associated with lower AD risk. Both rs174556 and rs3756963 influence AD risk in the Tunisian population and they are likely associated with high AA level. The combination of the two variants increases further the susceptibility to AD. We suggest that FADS1 and ELOVL2 variants could likely regulate the efficiency of AA biosynthesis which could be at the origin of inflammatory derivate.

ISSFAL Official Statement Number 6: The importance of measuring blood omega-3 long chain polyunsaturated fatty acid levels in research

A statement on measuring blood omega-3 long chain polyunsaturated fatty acid levels was developed and edited based on input from ISSFAL members and accepted by vote of the ISSFAL Board of Directors. Summary of Statement: Omega-3 long chain polyunsaturated fatty acid (n-3 LCPUFA) levels at baseline and post-intervention should be assessed and reported in future research to evaluate the efficacy of n-3 LCPUFA supplementation: b ecause; 1. there are numerous factors that affect n-3 LCPUFA levels in humans as described in the systematic literature review [1]; 2. assessing intake of n-3 LCPUFA from the diet and/or supplements is not sufficient to accurately determine n-3 LCPUFA levels in humans; 3. some studies do not provide sufficient doses of n-3 LCPUFA to produce a significant impact on bloodstream/organ content and there is substantial variability in the uptake of n-3 LPCUFA into tissues between individuals. In secondary analyses, clinical trials should consider the influence of fatty acid status (baseline, endpoint and change from baseline to endpoint) on the outcome variables.

Higher erythrocyte n-3 polyunsaturated fatty acid were associated with a better profile of DXA-derived body fat and fat distribution in adults

BACKGROUND

Previous studies have reported that high-dose supplementation of n-3 polyunsaturated fatty acids (PUFAs) may reduce the risk of metabolic diseases, but there is limited evidence of an effect on body fat. We examined the associations of erythrocyte n-3 PUFAs with body fat and fat distribution in a general population consuming a normal diet.

METHODS

This community-based cross-sectional study included 3075 Chinese (68% women, 40-75 years) recruited between 2008 and 2013. We collected general information and measured anthropometric indices; erythrocyte n-3 PUFAs (including α-C18:3, C20:5, C22:5 and C22:6) by gas-chromatography, and fat mass (FM) and %FM at the total body (TB), android (A) and gynoid (G) regions by dual-energy X-ray absorptiometry (DXA).

RESULTS

Both minimally and maximally adjusted models showed dose-dependent inverse associations of total and individual levels of erythrocyte n-3 PUFAs (except C20:5 n-3[EPA]) with adiposity indices. In the full model, the mean differences between quartiles 4 and 1 of total n-3 PUFAs were -1.60% (BMI), -4.06% (TB FM), -5.38% (A FM), -2.05% (G FM), -2.05% (TB %FM), -3.39% (A %FM) and -2.50% (% A/G); the ORs (95% CI) of %FM-derived obesity (≥25% for men, ≥35% for women) for the highest (vs. lowest) quartile were 0.70 (0.57, 0.86) for total n-3 PUFAs and 0.71 (0.58, 0.87), 0.96(0.78, 1.18), 0.82(0.67, 1.00), 0.66 (0.54, 0.81) for α-C18:3/C20:5/C22:5/C22:6 n-3, respectively. The favourable associations were more pronounced for the DXA-derived FM indices, measurements at the android region and for C22:6 n-3. No significant associations between C20:5 n-3 and the adiposity indices were observed.

CONCLUSIONS

Higher levels of circulating n-3 PUFAs were dose-dependently associated with better profiles of body fat and fat distribution, particularly in the abdominal regions in this population.

Influence of clinical characteristics on maternal DHA and other polyunsaturated fatty acid status in pregnancy: A systematic review

INTRODUCTION

Omega-3 DHA is important for the prevention of preterm birth, however there is limited knowledge of the determinants of omega-3 status during pregnancy. The primary objective of this systematic review was to synthesise data from existing studies assessing relationships between clinical factors and maternal DHA status.

MATERIALS AND METHODS

The Medline, Embase, Amed, and CINAHL databases were searched for studies reporting measures of maternal omega-3 status and one or more clinical characteristics.

RESULTS

Eighteen studies were included in the final analyses. Factors associated with a higher BMI (overweight, higher gestational weight gain, gestational diabetes), or lower parity were each associated with higher omega-3 status in the majority of studies, with mixed findings for other comparisons.

DISCUSSION

Inconsistent findings between studies make it difficult to draw clear conclusions about the relationship between clinical factors and maternal omega-3 DHA status. However, maternal overweight and associated metabolic conditions may increase lipid metabolism.

Single-Dose SDA-Rich Echium Oil Increases Plasma EPA, DPAn3, and DHA Concentrations

The omega-3 (n3) polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are associated with health benefits. The primary dietary source of EPA and DHA is seafood. Alpha-linoleic acid (ALA) has not been shown to be a good source for EPA and DHA; however, stearidonic acid (SDA)-which is naturally contained in echium oil (EO)-may be a more promising alternative. This study was aimed at investigating the short-term n3 PUFA metabolism after the ingestion of a single dose of EO. Healthy young male subjects (n = 12) ingested a single dose of 26 g of EO after overnight fasting. Plasma fatty acid concentrations and relative amounts were determined at baseline and 2, 4, 6, 8, 24, 48, and 72 h after the ingestion of EO. During the whole examination period, the participants received standardized nutrition. Plasma ALA and SDA concentrations increased rapidly after the single dose of EO. Additionally, EPA and DPAn3 concentrations both increased significantly by 47% after 72 h compared to baseline; DHA concentrations also significantly increased by 21% after 72 h. To conclude, EO increases plasma ALA, SDA, EPA, DPAn3, and DHA concentrations and may be an alternative source for these n3 PUFAs.

Predicting the effects of supplemental EPA and DHA on the omega-3 index

BACKGROUND

Supplemental long-chain omega-3 (n-3) fatty acids (EPA and DHA) raise erythrocyte EPA + DHA [omega-3 index (O3I)] concentrations, but the magnitude or variability of this effect is unclear.

OBJECTIVE

The purpose of this study was to model the effects of supplemental EPA + DHA on the O3I.

METHODS

Deidentified data from 1422 individuals from 14 published n-3 intervention trials were included. Variables considered included dose, baseline O3I, sex, age, weight, height, chemical form [ethyl ester (EE) compared with triglyceride (TG)], and duration of treatment. The O3I was measured by the same method in all included studies. Variables were selected by stepwise regression using the Bayesian information criterion.

RESULTS

Individuals supplemented with EPA + DHA (n = 846) took a mean ± SD of 1983 ± 1297 mg/d, and the placebo controls (n = 576) took none. The mean duration of supplementation was 13.6 ± 6.0 wk. The O3I increased from 4.9% ± 1.7% to 8.1% ± 2.7% in the supplemented individuals ( P < 0.0001). The final model included dose, baseline O3I, and chemical formulation type (EE or TG), and these explained 62% of the variance in response (P < 0.0001). The model predicted that the final O3I (and 95% CI) for a population like this, with a baseline concentration of 4.9%, given 850 mg/d of EPA + DHA EE would be ∼6.5% (95% CI: 6.3%, 6.7%). Gram for gram, TG-based supplements increased the O3I by about 1 percentage point more than EE products.

CONCLUSIONS

Of the factors tested, only baseline O3I, dose, and chemical formulation were significant predictors of O3I response to supplementation. The model developed here can be used by researchers to help estimate the O3I response to a given EPA + DHA dose and chemical form.

Survey of the erythrocyte EPA+DHA levels in the heart attack/stroke belt

BACKGROUND

The Omega-3 Index (O3I; erythrocyte EPA+DHA as a percent of total fatty acids) is inversely related to risk for cardiovascular disease (CVD). The cardioprotective target O3I is 8%-12%. O3I levels in American regions with high CVD risk are poorly characterized.

PURPOSE

To determine the O3I in individuals participating in a Seafood Nutrition Partnership (SNP) survey in seven US cities in the CVD "belt."

METHODS

Fingerstick blood samples were analyzed for the O3I.

RESULTS

The SNP cohort (n = 2177) had a mean (SD) O3I of 4.42% (1.12%). Only 1.2% were in the desirable range, whereas 42% had an undesirable (<4%) O3I. The mean (SD) O3I in a subset of 772 SNP subjects who were matched for age and sex with the Framingham study was 4.6% (1.2%) compared 5.3% (1.6%) in the Framingham cohort (p < 0.0001).

CONCLUSIONS

Individuals in the CVD "belt" had relatively low O3I levels. Since in other settings, a low O3I is associated with increased risk for CVD, this may be one factor contributing to the higher risk for CVD in this region of the US.

Omega-3 PUFA metabolism and brain modifications during aging

In Canada, 5.5 million (16% of Canadians) adults are >65 years old and projections suggest this number will be approximately 20% of Canadians by 2024. A major concern regarding old age is a decline in health, especially if this entails a loss of self-sufficiency and independence caused by a decline in cognition. The brain contains 60% of fat and is one of the most concentrated organs in long chain omega-3 fatty acids such as docosahexaenoic acid (DHA). During aging, there are physiological modifications in the metabolism of lipids that could also have consequences on brain structure and levels of DHA. This review will hence discuss the physiological modifications in the metabolism of lipids during aging with a focus on long chain omega-3 and omega-6 fatty acids and also outline the structural and functional modifications of the brain during aging including brain lipid modifications and its relation to higher levels of DHA and cognition. Therefore, in this review, we outline the importance of collecting more data on the biology of aging since it might highly improve our understanding about what are «normal» modifications occurring during aging and what can become pathological.

Translating plasma eicosapentaenoic acid concentrations into erythrocyte percentages of eicosapentaenoic acid plus docosahexaenoic acid during treatment with icosapent ethyl

BACKGROUND

The Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT) study demonstrated that 4 g/d of eicosapentaenoic acid (EPA) ethyl esters (icosapent ethyl [IPE]) reduced risk for major cardiovascular events by 25% in statin-treated patients with residual hypertriglyceridemia. How this treatment affected red blood cell (RBC) EPA and docosahexaenoic acid (DHA) levels (ie, the Omega-3 Index [O3I]) was not reported, but effects on plasma EPA concentrations were reported.

OBJECTIVE

The aim of the study was to estimate baseline and final O3I levels in REDUCE-IT.

METHODS

First, deidentified data from our laboratory on RBC and plasma EPA and DHA from 2311 patients with similar lipid profiles as those in REDUCE-IT were used to generate a regression equation, which was then used to estimate the O3I from plasma FA concentrations. Second, previously published data on the effects of IPE on RBC FA concentrations were also converted to the O3I.

RESULTS

Both approaches (from calculations and prior publications) suggested that baseline and follow-up O3I levels were about 5% and 7%, respectively. In addition, plasma EPA levels (but not the O3I) were noted to be influenced by triglyceride levels.

CONCLUSION

For patients using 4 g of IPE, an estimated O3I value of about 7% reflects a cardioprotective state. Plasma EPA concentrations may be ill-suited as treatment targets because they are confounded by triglyceride levels.

Prioritization of Variants for Investigation of Genotype-Directed Nutrition in Human Superpopulations

Dietary guidelines recommended by key health agencies are generally designed for a global population. However, ethnicity affects human disease and environment-gene interactions, including nutrient intake. Historically, isolated human populations with different genetic backgrounds have adapted to distinct environments with varying food sources. Ethnicity is relevant to the interaction of food intake with genes and disease susceptibility; yet major health agencies generally do not recommend food and nutrients codified by population genotypes and their frequencies. In this paper, we have consolidated published nutrigenetic variants and examine their frequencies in human superpopulations to prioritize these variants for future investigation of population-specific genotype-directed nutrition. The nutrients consumed by individuals interact with their genome and may alter disease risk. Herein, we searched the literature, designed a data model, and manually curated hundreds of papers. The resulting database houses 101 variants that reached significance (p < 0.05), from 35 population studies. Nutrigenetic variants associated with modified nutrient intake have the potential to reduce the risk of colorectal cancer, obesity, metabolic syndrome, type 2 diabetes, and several other diseases. Since many nutrigenetic studies have identified a major variant in some populations, we suggest that superpopulation-specific genotype-directed nutrition modifications be prioritized for future study and evaluation. Genotype-directed nutrition approaches to dietary modification have the potential to reduce disease risk in select human populations.

Validation of a Dietary Questionnaire to Screen Omega-3 Fatty Acids Levels in Healthy Adults

To facilitate a clinical observational study to identify healthy volunteers with low (defined as ≤4%) and high (defined as ≥5.5%) omega-3 indices, a dietary questionnaire to rapidly assess habitual dietary intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) was developed. This study aimed to determine the validity of this newly developed dietary questionnaire. One hundred and eight volunteers were included and were assessed for habitual dietary intake of EPA and DHA using the questionnaire. The United States Department of Agriculture food products database and nutrition fact label was referenced for calculation. Blood samples were collected for the analysis of fatty acids in whole blood specimens and to derive omega-3 indices. A linear correlation was observed between reported dietary consumption of EPA, DHA, EPA+DHA and the whole blood levels of EPA, DHA, and the omega-3 indices (r = 0.67, 0.62, 0.67, respectively, p < 0.001 for all). The findings also suggested that the questionnaire was substantially better at identifying volunteers with high omega-3 indices (sensitivity 89%, specificity 84%, and agreement 86%) compared to volunteers with low omega-3 indices (sensitivity 100%, specificity 66%, and agreement 42%). In conclusion, this newly developed questionnaire is an efficient tool for the assessment of omega-3 indices in study populations and is particularly effective in identifying individuals with high omega-3 indices.

Evaluation of a Rapid Assessment Questionnaire Using a Biomarker for Dietary Intake of n-3 Fatty Acids

While there is considerable evidence supporting health benefits of consuming diets high in omega-3 (n-3) fatty acids, there is no quick and effective tool to measure n-3 intake. The objective of this study was to evaluate the accuracy of a rapid assessment questionnaire (the Omega-3 Checklist) used to quantify intake of n-3 fatty acids. This was done by comparing n-3 intakes to blood biomarkers of n-3 exposure in a population of healthy men and women. In addition, a separate analysis was run including covariates age, sex, and weight, which have been shown to affect n-3 biomarker levels. Reported intake of eicosapentaenoic acid (EPA), docoshexaenoic acid (DHA), and EPA + DHA was correlated with erythrocyte EPA (Spearman's rank correlation r_s  = 0.51, p < 0.001), DHA (r_s  = 0.54, p < 0.001), and the Omega-3 Index (r_s  = 0.57, p < 0.001). These associations remained significant when controlling for age, sex, and weight. Therefore, the Omega-3 Checklist can be a useful, rapid assessment tool to estimate individuals' EPA and DHA intake.

Associations of medium and long chain omega-3 polyunsaturated fatty acids with blood pressure in Hispanic and non-Hispanic smokers and nonsmokers

Epidemiology studies and clinical trials have shown that omega-3 polyunsaturated fatty acids (n-3 PUFAs) are inversely associated with blood pressure. We sought to determine the influence of cigarette smoking and Hispanic ethnicity on this association. Age- and sex-matched smokers and nonsmokers (n = 98) 19-50 years old lacking cardiovascular disease were recruited. Systolic and diastolic blood pressure (SBP, DBP), heart rate, HbA1c, lipids, BMI, and RBC fatty acids were measured. The omega-3 index (percent eicosapentaenoic and docosahexaenoic acid, EPA+DHA, in RBCs) was significantly lower in smokers (Smokers: 3.19 ± 0.86%; Nonsmokers, 3.88 ± 1.05%, p = 0.001) and Hispanics (Hispanic 3.32 ± 0.93%; Non-Hispanic, 3.82 ± 1.03%, p = 0.006). DHA exhibited a significant inverse association with BP in both smokers and nonsmokers, while alpha-linolenic acid (ALA) exhibited a significant positive association with BP only in smokers. Multiple regression analyses showed that BMI, DHA, smoking status, and smoking status*ALA interaction significantly predicted SBP (p < 0.0001, R2 = 0.44) and DBP (p < 0.0001, R2 = 0.33), while ethnicity had no effect. The observed lower BP when DHA levels are high suggests a possible protective role of DHA on BP in normotensive smokers and nonsmokers. Additionally, the observed higher BP when ALA levels are high only in smokers suggests that ALA may influence the BP-lowering effects of chronic smoking.

Peripheral Artery Disease Is Associated with a Deficiency of Erythrocyte Membrane n-3 Polyunsaturated Fatty Acids

Population-based data suggest that individuals who consume large dietary amounts of n-3 polyunsaturated fatty acids (PUFA) have lower odds of peripheral artery disease (PAD); however, clinical studies examining n-3 PUFA levels in patients with PAD are sparse. The objective of this study is to compare erythrocyte membrane fatty acid (FA) content between patients with PAD and controls. We conducted a cross-sectional study of 179 vascular surgery outpatients (controls, 34; PAD, 145). A blood sample was drawn and the erythrocyte FA content was assayed using capillary gas chromatography. We calculated the ratio of the n-3 PUFA eicosapentaenoic acid (EPA) to the n-6 PUFA arachidonic acid (ARA) as well as the omega-3 index (O3I), a measure of erythrocyte content of the n-3 PUFA, EPA, and docosahexaenoic acid (DHA), expressed as a percentage of total erythrocyte FA. Compared with controls, patients with PAD smoked more and were more likely to have hypertension and hyperlipidemia (p < 0.05). Patients with PAD had a lower mean O3I (5.0 ± 1.7% vs 6.0 ± 1.6%, p < 0.001) and EPA:ARA ratio (0.04 ± 0.02 vs 0.05 ± 0.05, p < 0.001), but greater mean total saturated fats (39.5 ± 2.5% vs 38.5 ± 2.6%, p = 0.01). After adjusting for several patient characteristics, comorbidities, and medications, an absolute decrease of 1% in the O3I was associated with 39% greater odds of PAD (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.03-1.86, and p = 0.03). PAD was associated with a deficiency of erythrocyte n-3 PUFA, a lower EPA:ARA ratio, and greater mean total saturated fats. These alterations in FA content may be involved in the pathogenesis or development of poor outcomes in PAD.

Non-dietary factors associated with n-3 long-chain PUFA levels in humans - a systematic literature review

Numerous health benefits are attributed to the n-3 long-chain PUFA (n-3 LCPUFA); EPA and DHA. A systematic literature review was conducted to investigate factors, other than diet, that are associated with the n-3 LCPUFA levels. The inclusion criteria were papers written in English, carried out in adult non-pregnant humans, n-3 LCPUFA measured in blood or tissue, data from cross-sectional studies, or baseline data from intervention studies. The search revealed 5076 unique articles of which seventy were included in the qualitative synthesis. Three main groups of factors potentially associated with n-3 LCPUFA levels were identified: (1) unmodifiable factors (sex, genetics, age), (2) modifiable factors (body size, physical activity, alcohol, smoking) and (3) bioavailability factors (chemically bound form of supplements, krill oil v. fish oil, and conversion of plant-derived α-linolenic acid (ALA) to n-3 LCPUFA). Results showed that factors positively associated with n-3 LCPUFA levels were age, female sex (women younger than 50 years), wine consumption and the TAG form. Factors negatively associated with n-3 LCPUFA levels were genetics, BMI (if erythrocyte EPA and DHA levels are &lt;5·6 %) and smoking. The evidence for girth, physical activity and krill oil v. fish oil associated with n-3 LCPUFA levels is inconclusive. There is also evidence that higher ALA consumption leads to increased levels of EPA but not DHA. In conclusion, sex, age, BMI, alcohol consumption, smoking and the form of n-3 LCPUFA are all factors that need to be taken into account in n-3 LCPUFA research.

Omega-3 Polyunsaturated Fatty Acid Deficiency and Progressive Neuropathology in Psychiatric Disorders: A Review of Translational Evidence and Candidate Mechanisms

Meta-analytic evidence indicates that mood and psychotic disorders are associated with both omega-3 polyunsaturated fatty acid (omega-3 PUFA) deficits and progressive regional gray and white matter pathology. Although the association between omega-3 PUFA insufficiency and progressive neuropathological processes remains speculative, evidence from translational research suggests that omega-3 PUFA insufficiency may represent a plausible and modifiable risk factor not only for enduring neurodevelopmental abnormalities in brain structure and function, but also for increased vulnerability to neurodegenerative processes. Recent evidence from human neuroimaging studies suggests that lower omega-3 PUFA intake/status is associated with accelerated gray matter atrophy in healthy middle-aged and elderly adults, particularly in brain regions consistently implicated in mood and psychotic disorders, including the amygdala, anterior cingulate, hippocampus, prefrontal cortex, and temporal cortex. Human neuroimaging evidence also suggests that both low omega-3 PUFA intake/status and psychiatric disorders are associated with reductions in white matter microstructural integrity and increased rates of white matter hyperintensities. Preliminary evidence suggests that increasing omega-3 PUFA status is protective against gray matter atrophy and deficits in white matter microstructural integrity in patients with mood and psychotic disorders. Plausible mechanisms mediating this relationship include elevated pro-inflammatory signaling, increased synaptic regression, and reductions in cerebral perfusion. Together these associations encourage additional neuroimaging research to directly investigate whether increasing omega-3 PUFA status can mitigate neuropathological processes in patients with, or at high risk for, psychiatric disorders.

Leveraging summary statistics to make inferences about complex phenotypes in large biobanks

As genetic sequencing becomes less expensive and data sets linking genetic data and medical records (e.g., Biobanks) become larger and more common, issues of data privacy and computational challenges become more necessary to address in order to realize the benefits of these datasets. One possibility for alleviating these issues is through the use of already-computed summary statistics (e.g., slopes and standard errors from a regression model of a phenotype on a genotype). If groups share summary statistics from their analyses of biobanks, many of the privacy issues and computational challenges concerning the access of these data could be bypassed. In this paper we explore the possibility of using summary statistics from simple linear models of phenotype on genotype in order to make inferences about more complex phenotypes (those that are derived from two or more simple phenotypes). We provide exact formulas for the slope, intercept, and standard error of the slope for linear regressions when combining phenotypes. Derived equations are validated via simulation and tested on a real data set exploring the genetics of fatty acids.

The effect of camelina sativa oil and fish intakes on fatty acid compositions of blood lipid fractions

BACKGROUND AND AIMS

Blood lipid fractions serve as objective biomarkers of dietary fat intake. It is unclear which fatty acid pool most accurately reflects the dietary intakes of different n-3 PUFAs. We aimed to investigate the effect of fish and camelina sativa oil (CSO) intakes on fatty acid composition of erythrocyte membranes (EM), plasma phospholipids (PL), cholesteryl esters (CE) and triglycerides (TG). We also aimed to identify the most appropriate blood lipid fraction for assessing n-3 PUFA intake.

METHODS AND RESULTS

Altogether 79 volunteers with impaired glucose metabolism were randomly assigned either to CSO, fatty fish, lean fish or control groups for 12 weeks. Fatty acid compositions of lipid pools were measured by gas chromatography. The proportion of alpha-linolenic acid (ALA) increased in all lipid pools in the CSO group (false discovery rate (FDR) p < 0.001 for all). Similarly, the proportions of EPA and DHA increased in all lipid fractions in the fatty fish group (FDR p < 0.001 for EM, PL and CE; FDR p = 0.005 for TG; FDR p < 0.001 for EM, PL, CE; FDR p < 0.007 for TG, respectively). Changes in the dietary intakes of ALA, EPA and DHA correlated with the changes in their proportions in all lipid pools (r = 0.3-0.5, p < 0.05).

CONCLUSION

There is no difference in the ability of blood lipid fractions in reflecting the dietary intake of different n-3 PUFAs over a time period of 12 weeks in subjects with high baseline omega-3 index. This trial was registered in Clinicaltrials.gov (NCT01768429).

Maternal Pre-Pregnancy Obesity Attenuates Response to Omega-3 Fatty Acids Supplementation During Pregnancy

Maternal obesity is associated with adverse offspring outcomes. Inflammation and deficiency of anti-inflammatory nutrients like omega(n)-3 polyunsaturated fatty acids (PUFA) may contribute to these associations. Fetal supply of n-3 PUFA is dependent on maternal levels and studies have suggested that improved offspring outcomes are associated with higher maternal intake. However, little is known about how maternal obesity affects the response to n-3 supplementation during pregnancy. We sought to determine (1) the associations of obesity with PUFA concentrations and (2) if the systemic response to n-3 supplementation differs by body mass index (BMI). This was a secondary analysis of 556 participants (46% lean, 28% obese) in the Maternal-Fetal Medicine Units Network trial of n-3 (Docosahexaenoic acid (DHA) + Eicosapentaenoic acid (EPA)) supplementation, in which participants had 2g/day of n-3 (n = 278) or placebo (n = 278) from 19 to 22 weeks until delivery. At baseline, obese women had higher plasma n-6 arachidonic acid concentrations (β: 0.96% total fatty acids; 95% Confidence Interval (CI): 0.13, 1.79) and n-6/n-3 ratio (β: 0.26 unit; 95% CI: 0.05, 0.48) compared to lean women. In the adjusted analysis, women in all BMI groups had higher n-3 concentrations following supplementation, although obese women had attenuated changes (β = -2.04%, CI: -3.19, -0.90, interaction p = 0.000) compared to lean women, resulting in a 50% difference in the effect size. Similarly, obese women also had an attenuated reduction (β = 0.94 units, CI: 0.40, 1.47, interaction p = 0.046) in the n-6/n-3 ratio (marker of inflammatory status), which was 65% lower compared to lean women. Obesity is associated with higher inflammation and with an attenuated response to n-3 supplementation in pregnancy.

Omega-3 fatty acids in coronary heart disease: Recent updates and future perspectives

Incidence of coronary heart disease (CHD) increases worldwide with varying etiological factors. In addition to the control of risk factors, dietary modification has been recommended to reduce the prevalence. Omega-3 (ω-3) fatty acids (FAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), of fish oil are beneficial for the prevention of CHD. The effect can be ascribed to anti-inflammatory, vasodilating, antiarrhythmic, antihypertensive activities and lowering of triacyl glycerol level. The American Heart Association advises two fish meals per week in subjects without CHD or supplementation of 1 g of EPA plus DHA per day in subjects with CHD. Despite the beneficial effects of EPA/DHA reported in some of the clinical trials, results of many others were inconsistent that can be ascribed to short duration of studies, low doses of ω-3 FAs, variations in the EPA:DHA ratio, selection of patients with different risk factors or interaction of ω-3 FAs with drugs used in the therapy. Therefore, well designed clinical trials in various populations are warranted. This article discusses the current situation and future prospective of ω-3 FAs in CHD.