Omega-3 Fatty Acid Supplementation and Cardiovascular Disease Risk: Glass Half Full or Time to Nail the Coffin Shut?

Effect of n-3 polyunsaturated fatty acids on ischemic heart disease and cardiometabolic risk factors: a two-sample Mendelian randomization study

BACKGROUND

The cardioprotective ability of n-3 polyunsaturated fatty acids (PUFAs) is controversial. Most studies suggest a specific role for PUFAs in cardioprotection from ischemic heart disease (IHD). However, few studies have used genetic biomarkers of n-3 PUFAs to examine their potential relationships with IHD. This study aimed to use Mendelian randomization to evaluate whether genetically-predicted n-3 PUFAs affect IHD and cardiometabolic risk factors (CRFs).

METHODS

Genetic variants strongly (p < 5 × 10^-8) and independently (r² > 0.1) associated with n-3 PUFAs were derived from the CHARGE Consortium (including 8,866 subjects of European ancestry) and were used as instrumental variables (IVs) for evaluating the effect of n-3 PUFAs, including α-linolenic acid (ALA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA). Data on the associations between the IVs and IHD, myocardial infarction, and CRFs (including diabetes, lipids, blood pressure, body mass index, and waist-to-hip ratio (WHR)) were obtained from the UK Biobank SOFT CAD GWAS with the CARDIoGRAMplusC4D 1000 Genomes-based GWAS (113,937 IHD cases and 339,115 controls), the Myocardial Infarction Genetics and CARDIoGRAM Exome consortia (42,335 MI cases and 78,240 controls), the DIAbetes Genetics Replication And Meta-analysis consortium (26,676 diabetes mellitus cases and 132,532 controls), the Global Lipids Genetics Consortium (n = 196,475), the International Consortium for Blood Pressure (n = 69,395), and the meta-analysis of GWAS for body fat distribution in the UK Biobank and Genetic Investigation of Anthropometric Traits (n = 694,649).

RESULTS

Genetically-predicted higher ALA was associated with lower risk of IHD, type 2 diabetes (T2D), and lower serum lipids. The effect size per 0.05-unit increase (about 1 standard deviation) in plasma ALA level) was - 1.173 (95% confidence interval - 2.214 to - 0.133) for IHD. DPA and EPA had no association with IHD but were associated with a higher risk of T2D, higher levels of lipids or WHR. DHA had no association with IHD or CRFs.

CONCLUSIONS

Our study suggests a benefit of ALA for IHD and its main risk factors. DHA, DPA, and EPA had no association with IHD but were partly associated with increasing cardiometabolic risk factors.

Perspective: Planning and Conducting Statistical Analyses for Human Nutrition Randomized Controlled Trials: Ensuring Data Quality and Integrity

Appropriate planning, execution, and reporting of statistical methods and results is critical for research transparency, validity, and reproducibility. This paper provides an overview of best practices for developing a statistical analysis plan a priori, conducting statistical analyses, and reporting statistical methods and results for human nutrition randomized controlled trials (RCTs). Readers are referred to the other NURISH (NUtrition inteRventIon reSearcH) publications for detailed information about the preparation and conduct of human nutrition RCTs. Collectively, the NURISH series outlines best practices for conducting human nutrition research.

Can the biological mechanisms of ageing be corrected by food supplementation. The concept of health care over sick care

"From care for the sick to care for health" implies that age-related diseases and discomforts, which impair the quality of life, should be prevented rather than treated. Healthy lifestyle and nutrition, and hormone supplementation - when needed - are of crucial importance. Food supplementation with nutraceuticals composed of vitamins, oligo-minerals, plant extracts and essential amino- and fatty acids should reduce age-related oxidative and epigenetic damage to DNA, and inhibit inflammatory and metabolic impairment. This study of the potential beneficial effects of novel nutraceuticals on the biological mechanisms of physical and mental ageing suggests these supplements may be scientifically justified. In the absence of adverse side effects and the expected favourable effect on the quality-adjusted life years, the benefit over risk ratio of nutraceutical supplementation should be positive.

Omega-3 polyunsaturated fatty acids impinge on CD4+ T cell motility and adipose tissue distribution via direct and lipid mediator-dependent effects

AIMS

Adaptive immunity contributes to the pathogenesis of cardiovascular metabolic disorders (CVMD). The omega-3 polyunsaturated fatty acids (n-3PUFA) are beneficial for cardiovascular health, with potential to improve the dysregulated adaptive immune responses associated with metabolic imbalance. We aimed to explore the mechanisms through which n-3PUFA may alter T cell motility and tissue distribution to promote a less inflammatory environment and improve lymphocyte function in CVMD.

METHODS AND RESULTS

Using mass spectrometry lipidomics, cellular, biochemical, and in vivo and ex vivo analyses, we investigated how eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the main n-3PUFA, modify the trafficking patterns of activated CD4+ T cells. In mice subjected to allogeneic immunization, a 3-week n-3PUFA-enriched diet reduced the number of effector memory CD4+ T cells found in adipose tissue, and changed the profiles of eicosanoids, octadecanoids, docosanoids, endocannabinoids, 2-monoacylglycerols, N-acyl ethanolamines, and ceramides, in plasma, lymphoid organs, and fat tissues. These bioactive lipids exhibited differing chemotactic properties when tested in chemotaxis assays with activated CD4+ T cells in vitro. Furthermore, CD4+ T cells treated with EPA and DHA showed a significant reduction in chemokinesis, as assessed by trans-endothelial migration assays, and, when implanted in recipient mice, demonstrated less efficient migration to the inflamed peritoneum. Finally, EPA and DHA treatments reduced the number of polarized CD4+ T cells in vitro, altered the phospholipid composition of membrane microdomains and decreased the activity of small Rho GTPases, Rhoα, and Rac1 instrumental in cytoskeletal dynamics.

CONCLUSIONS

Our findings suggest that EPA and DHA affect the motility of CD4+ T cells and modify their ability to reach target tissues by interfering with the cytoskeletal rearrangements required for cell migration. This can explain, at least in part, the anti-inflammatory effects of n-3PUFA supporting their potential use in interventions aiming to address adipocyte low-grade inflammation associated with cardiovascular metabolic disease.

Risk of cardiovascular events in patients with hypertriglyceridaemia: A review of real-world evidence

AIMS

To describe the real-world prevalence and consequences of hypertriglyceridaemia.

MATERIALS AND METHODS

We searched two large patient databases, the National Health and Nutrition Examination Survey (NHANES) database (2007-2014) and the Optum Research Database, as well as electronic medical records from two Kaiser Permanente regions.

RESULTS

The NHANES data showed that ~26% of US adults, including nearly one-third of statin users, had at least borderline hypertriglyceridaemia (triglycerides [TGs] ≥1.69 mmol/L), and ~40% of adults with diabetes had levels of ≥150 mg/dL despite statin use. The Optum analyses demonstrated that those with TG levels ≥1.69 mmol/L who were on statins had a significantly increased risk of composite initial major cardiovascular (CV) events (hazard ratio [HR] 1.26, 95% confidence interval [CI] 1.19-1.34; P < 0.001 vs. patients with TGs <150 mg/dL). This was accompanied by increased healthcare utilization and direct healthcare costs (HR 1.12, 95% CI 1.08-1.16; P < 0.001). In the analyses of the Kaiser Permanente records, patients with diabetes and TG levels 2.26-5.64 mmol/L had significantly higher adjusted incidence rates of non-fatal myocardial infarction (rate ratio 1.30, 95% CI 1.08-1.58; P = 0.006), non-fatal stroke (rate ratio 1.23; 95% CI 1.01-1.49; P = 0.037) and coronary revascularization (rate ratio 1.21; 95% CI 1.02-1.43; P = 0.027), but not unstable angina (rate ratio 1.33; 95% CI 0.87-2.03; P = 0.185) compared with patients with TG levels <1.69 mmol/L.

CONCLUSIONS

Real-world analyses suggest that elevated TGs are prevalent and commonly associated with increased CV risk. CV outcomes trials in patients with established hypertriglyceridaemia will clarify whether strategies to reduce TG levels can ameliorate residual CV risk in patients taking statins.

Emirates Diabetes Society Consensus Guidelines for the Management of Type 2 Diabetes Mellitus – 2020

Rapid urbanisation and socioeconomic development in the United Arab Emirates (UAE) have led to the widespread adoption of a sedentary lifestyle and Westernised diet in the local population and consequently a high prevalence of obesity and diabetes. In 2019, International Diabetes Federation statistics reported a diabetes prevalence rate of 16.3% for the adult population in the UAE. In view of the wealth of recent literature on diabetes care and new pharmacotherapeutics, the Emirates Diabetes Society convened a panel of experts to update existing local guidelines with international management recommendations. The goal is to improve the standard of care for people with diabetes through increased awareness of these management practices among healthcare providers licensed by national health authorities. These consensus guidelines address the screening, diagnosis and management of type 2 diabetes mellitus in adults including individuals at risk of developing the disease.

Genome-Wide Association Study for Serum Omega-3 and Omega-6 Polyunsaturated Fatty Acids: Exploratory Analysis of the Sex-Specific Effects and Dietary Modulation in Mediterranean Subjects with Metabolic Syndrome

Many early studies presented beneficial effects of polyunsaturated fatty acids (PUFA) on cardiovascular risk factors and disease. However, results from recent meta-analyses indicate that this effect would be very low or nil. One of the factors that may contribute to the inconsistency of the results is that, in most studies, genetic factors have not been taken into consideration. It is known that fatty acid desaturase (FADS) gene cluster in chromosome 11 is a very important determinant of plasma PUFA, and that the prevalence of the single nucleotide polymorphisms (SNPs) varies greatly between populations and may constitute a bias in meta-analyses. Previous genome-wide association studies (GWAS) have been carried out in other populations and none of them have investigated sex and Mediterranean dietary pattern interactions at the genome-wide level. Our aims were to undertake a GWAS to discover the genes most associated with serum PUFA concentrations (omega-3, omega-6, and some fatty acids) in a scarcely studied Mediterranean population with metabolic syndrome, and to explore sex and adherence to Mediterranean diet (MedDiet) interactions at the genome-wide level. Serum PUFA were determined by NMR spectroscopy. We found strong robust associations between various SNPs in the FADS cluster and omega-3 concentrations (top-ranked in the adjusted model: FADS1-rs174547, p = 3.34 × 10-14; FADS1-rs174550, p = 5.35 × 10-14; FADS2-rs1535, p = 5.85 × 10-14; FADS1-rs174546, p = 6.72 × 10-14; FADS2-rs174546, p = 9.75 × 10-14; FADS2- rs174576, p = 1.17 × 10-13; FADS2-rs174577, p = 1.12 × 10-12, among others). We also detected a genome-wide significant association with other genes in chromosome 11: MYRF (myelin regulatory factor)-rs174535, p = 1.49 × 10-12; TMEM258 (transmembrane protein 258)-rs102275, p = 2.43 × 10-12; FEN1 (flap structure-specific endonuclease 1)-rs174538, p = 1.96 × 10-11). Similar genome-wide statistically significant results were found for docosahexaenoic fatty acid (DHA). However, no such associations were detected for omega-6 PUFAs or linoleic acid (LA). For total PUFA, we observed a consistent gene*sex interaction with the DNTTIP2 (deoxynucleotidyl transferase terminal interacting protein 2)-rs3747965 p = 1.36 × 10-8. For adherence to MedDiet, we obtained a relevant interaction with the ME1 (malic enzyme 1) gene (a gene strongly regulated by fat) in determining serum omega-3. The top-ranked SNP for this interaction was ME1-rs3798890 (p = 2.15 × 10-7). In the regional-wide association study, specifically focused on the FADS1/FASD2/FADS3 and ELOVL (fatty acid elongase) 2/ELOVL 5 regions, we detected several statistically significant associations at p < 0.05. In conclusion, our results confirm a robust role of the FADS cluster on serum PUFA in this population, but the associations vary depending on the PUFA. Moreover, the detection of some sex and diet interactions underlines the need for these associations/interactions to be studied in all specific populations so as to better understand the complex metabolism of PUFA.

Concentration-Dependent Effects of N-3 Long-Chain Fatty Acids on Na,K-ATPase Activity in Human Endothelial Cells

N-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) seem to prevent endothelial dysfunction, a crucial step in atherogenesis, by modulating the levels of vasoactive molecules and by influencing Na,K-ATPase activity of vascular myocytes. The activity of endothelial Na,K-ATPase controls the ionic homeostasis of the neighboring cells, as well as cell function. However, controversy exists with respect to the vascular protective effect of EPA and DHA. We argue that this dispute might be due to the use of different concentrations of EPA and DHA in different studies. Therefore, this study was designed to define an optimal concentration of EPA and DHA to investigate endothelial function. For this purpose, human endothelial cells were exposed for 24 h to different concentrations of DHA or EPA (0–20 μM) to study membrane fluidity, peroxidation potential and Na,K-ATPase activity. EPA and DHA were linearly incorporated and this incorporation was mirrored by the linear increase of unsaturation index, membrane fluidity, and peroxidation potential. Na,K-ATPase activity peaked at 3.75 μM of EPA and DHA and then gradually decreased. It is noteworthy that DHA effects were always more pronounced than EPA. Concluding, low concentrations of EPA and DHA minimize peroxidation sensitivity and optimize Na,K-ATPase activity.

[Association of polyunsaturated fatty acids treatment with coronary mortality. A meta-analysis]

AIM

A meta-analysis was undertaken to sum up data on long-chain polyunsaturated fatty acids treatment and coronary deaths.

METHODS

Only studies with no less than 500 participants and length of follow-up no less than one year were included. Total number of studies was 13 with 127455 participants.

RESULTS

Fixed factor (Peto) model demonstrated significant decrease in cardiac deaths in polyunsaturated fatty acids -treated group. (OR=0,89, 95%CI: 0,83-0,95, р=0,001). Random factor model confidence interval also does not included one (OR=0,88, 95%CI: 0,80-0,97, p=0.008). Subgroup analysis of studies that used therapy with 460 mg eicosapentaenoic acid and 380 docosahexaenoic acid per day demonstrated significant reduction in cardiac deaths (OR=0,84, 95%CI: 0,77-0,92) in both fixed factor and random factor models.

CONCLUSION

Correspondingly supplementation with polyunsaturated fatty acids associated with lower coronary mortality.

Association of Dietary n3 and n6 Fatty Acids Intake with Hypertension: NHANES 2007-2014

We conducted this cross-sectional study in the American general population to explore the association of dietary n3 and n6 fatty acids intake and the risk of hypertension. We used data from the National Health and Nutrition Examination Survey (NHANES) 2007–2014 in this study. We obtained dietary n3 and n6 fatty acids data through two 24 h dietary recall interviews and n3, n6 fatty acids intake were adjusted by weight. We defined hypertension as now taking prescribed medicine for hypertension or blood pressure above 130/80 mmHg. We applied binary logistic regression, multinomial logistic regression, and restricted cubic spline to evaluate the associations of dietary n3 and n6 fatty acids intake with hypertension. A total of 18,434 participants were included in this study. In the multivariate-adjusted model 2, the odds ratios (ORs) with 95% confidence interval (CI) of hypertension were 0.58 (0.49–0.68), 0.53 (0.45–0.63), and 0.92 (0.80–1.06) for the highest versus the lowest tertile of dietary n3, n6 fatty acids intake and n6:n3 ratio, respectively. Further excluded participants with hypertension history, the ORs with 95% CI of newly diagnosed hypertension were 0.60 (0.50–0.73), 0.52 (0.43–0.62), and 0.95 (0.79–1.14) for the highest versus lowest tertile of dietary n3, n6 fatty acids intake and n6:n3 ratio, respectively. Dose-response analyses showed that the risk of hypertension was associated with dietary n3 and n6 fatty acids intake. Our study suggested that dietary n3 and n6 fatty acids intake were inversely associated with the risk of hypertension in US adults.

Effect of linoleic acid on ischemic heart disease and its risk factors: a Mendelian randomization study

BACKGROUND

The role of n-6 polyunsaturated fatty acids (PUFAs) in ischemic heart disease (IHD) is controversial, and dietary guidelines vary. Observationally, lower saturated fat intake and higher intake of vegetable oils rich in linoleic acid (LA), the main n-6 PUFA, is associated with lower IHD and diabetes; however, randomized controlled trials have not fully corroborated these benefits. We assessed how genetically predicted LA affected IHD and its risk factors, including diabetes, lipids, and blood pressure. We also assessed the role of LA in reticulocyte count, the red blood cell precursor, which has recently been identified as a possible causal factor in IHD.

METHODS

Two-sample instrumental variable analysis with genetic instruments, i.e., Mendelian randomization, was used to obtain unconfounded estimates using genetic variants strongly (p value < 5 × 10-8) and solely associated with LA, applied to an IHD case (n ≤ 76,014)-control (n ≤ 264,785) study (mainly based on the meta-analysis of CARDIoGRAMplusC4D 1000 Genomes and UK Biobank CAD SOFT GWAS), the DIAbetes Genetics Replication And Meta-analysis diabetes case (n = 26,676)-control (n = 132,532) study, lipids from the Global Lipids Genetics Consortium Results (n = 196,475), and reticulocyte count and blood pressure from the UK Biobank (n ≤ 361,194). A weighted median and Mendelian randomization Egger were used for sensitivity analysis.

RESULTS

Genetically predicted LA was not associated with IHD or systolic blood pressure. Genetically predicted higher serum LA was associated with lower diabetes (odds ratio (OR) 0.97 per percentage in total fatty acid increase in LA, 95% confidence interval (CI) 0.96 to 0.99) and lower lipids (low-density lipoprotein, high-density lipoprotein, and total cholesterol), but may be associated with higher diastolic blood pressure. The findings were robust to different single nucleotide polymorphism (SNP) selections, analytic methods, and correction for multiple testing.

CONCLUSIONS

Our novel study suggests a benefit of LA for diabetes and lipids but no benefit for IHD, blood pressure, or reticulocyte count. Explicating these paradoxical findings would facilitate identification of effective new interventions for diabetes and IHD.

n-3 Fatty acids and risk for fatal coronary disease

The purpose of this review is to consider the effects of the long-chain n-3 fatty acids found in marine foods, EPA and DHA, on risk for CVD, particularly fatal outcomes. It will examine both epidemiological and randomised controlled trial findings. The former studies usually examine associations between the dietary intake or the blood levels of EPA + DHA and CVD outcomes or, on occasion, total mortality. For example, our studies in the Framingham Heart Study and in the Women's Health Initiative Memory Study have demonstrated significant inverse relations between erythrocyte EPA + DHA levels (i.e. the Omega-3 Index) and total mortality. Recent data from the Cardiovascular Health Study reported the same relations between plasma phospholipid n-3 levels and overall healthy ageing. As regards randomised trials, studies in the 1990s and early 2000s were generally supportive of a cardiovascular benefit for fish oils (which contain EPA + DHA), but later trials were generally not able to duplicate these findings, at least for total CVD events. However, when restricted to effects on risk for fatal events, meta-analyses have shown consistent benefits for n-3 treatment. Taken together, the evidence is strong for a cardioprotective effect of EPA + DHA, especially when consumed in sufficient amounts to raise blood levels into healthy ranges. Establishing target EPA + DHA intakes to reduce risk for cardiovascular death is a high priority.

Supplementation-Dependent Effects of Vegetable Oils with Varying Fatty Acid Compositions on Anthropometric and Biochemical Parameters in Obese Women

Fatty acid (FA) composition is a determinant of the physiological effects of dietary oils. This study investigated the effects of vegetable oil supplementation with different FA compositions on anthropometric and biochemical parameters in obese women on a hypocaloric diet with lifestyle modifications. Seventy-five women (body mass index, BMI, 30⁻39.9kg/m²) were randomized based on 8-week oil supplementation into four experimental groups: the coconut oil group (CoG, n = 18), the safflower oil group (SafG, n = 19), the chia oil group (ChG, n = 19), and the soybean oil placebo group (PG, n = 19). Pre- and post-supplementation weight, anthropometric parameters, and body fat (%BF), and lean mass percentages (%LM) were evaluated, along with biochemical parameters related to lipid and glycidemic profiles. In the anthropometric evaluation, the CoG showed greater weight loss (Δ% = -8.54 ± 2.38), and reduced BMI (absolute variation, Δabs = -2.86 ± 0.79), waist circumference (Δabs = -6.61 ± 0.85), waist-to-height ratio (Δabs = -0.041 ± 0.006), conicity index (Δabs = -0.03 ± 0.016), and %BF (Δabs = -2.78 ± 0.46), but increased %LM (Δabs = 2.61 ± 1.40) (p < 0.001). Moreover, the CoG showed a higher reduction in biochemical parameters of glycemia (Δabs = -24.71 ± 8.13) and glycated hemoglobin (Δabs = -0.86 ± 0.28) (p < 0.001). The ChG showed a higher reduction in cholesterol (Δabs = -45.36 ± 0.94), low-density lipoprotein cholesterol (LDLc; Δabs = -42.53 ± 22.65), and triglycerides (Δabs = -49.74 ± 26.3), but an increase in high-density lipoprotein cholesterol (HDLc; abs = 3.73 ± 1.24, p = 0.007). Coconut oil had a more pronounced effect on abdominal adiposity and glycidic profile, whereas chia oil had a higher effect on improving the lipid profile. Indeed, supplementation with different fatty acid compositions resulted in specific responses.