Effects of purified eicosapentaenoic acid and docosahexaenoic acid on platelet, fibrinolytic and vascular function in hypertensive type 2 diabetic patients

Dietary n-3 polyunsaturated fatty acids alter the number, fatty acid profile and coagulatory activity of circulating and platelet-derived extracellular vesicles: a randomized, controlled crossover trial

BACKGROUND

Extracellular vesicles (EVs) are proposed to play a role in the development of cardiovascular diseases (CVDs) and are considered emerging markers of CVDs. n-3 PUFAs are abundant in oily fish and fish oil and are reported to reduce CVD risk, but there has been little research to date examining the effects of n-3 PUFAs on the generation and function of EVs.

OBJECTIVES

We aimed to investigate the effects of fish oil supplementation on the number, generation, and function of EVs in subjects with moderate risk of CVDs.

METHODS

A total of 40 participants with moderate risk of CVDs were supplemented with capsules containing either fish oil (1.9 g/d n-3 PUFAs) or control oil (high-oleic safflower oil) for 12 wk in a randomized, double-blind, placebo-controlled crossover intervention study. The effects of fish oil supplementation on conventional CVD and thrombogenic risk markers were measured, along with the number and fatty acid composition of circulating and platelet-derived EVs (PDEVs). PDEV proteome profiles were evaluated, and their impact on coagulation was assessed using assays including fibrin clot formation, thrombin generation, fibrinolysis, and ex vivo thrombus formation.

RESULTS

n-3 PUFAs decreased the numbers of circulating EVs by 27%, doubled their n-3 PUFA content, and reduced their capacity to support thrombin generation by >20% in subjects at moderate risk of CVDs. EVs derived from n-3 PUFA-enriched platelets in vitro also resulted in lower thrombin generation, but did not alter thrombus formation in a whole blood ex vivo assay.

CONCLUSIONS

Dietary n-3 PUFAs alter the number, composition, and function of EVs, reducing their coagulatory activity. This study provides clear evidence that EVs support thrombin generation and that this EV-dependent thrombin generation is reduced by n-3 PUFAs, which has implications for prevention and treatment of thrombosis.

CLINICAL TRIAL REGISTRY

This trial was registered at clinicaltrials.gov as NCT03203512.

Omega-3 fatty acids and endothelial function: A GRADE-assessed systematic review and meta-analysis

INTRODUCTION

N-3 polyunsaturated fatty acids (PUFAs) supplementation has been reported to have an impact on flow-mediated dilatation (FMD), a conventionally used clinical technique for estimating endothelial dysfunction. However, its proven effects on endothelial function are unclear. This systematic review and meta-analysis were conducted to evaluate the effects of n-3 PUFAs supplementation on FMD of the brachial artery.

METHOD

This study was performed following the PRISMA guidelines. To identify eligible RCTs, a systematic search was completed in PubMed/Medline, Scopus and Web of Science using relevant keywords. A fixed- or random-effects model was utilized to estimate the weighted mean difference (WMD) and 95% confidence interval (95% CI).

RESULTS

Thirty-two studies (with 35 arms) were included in this meta-analysis, involving 2385 subjects with intervention duration ranging from 4 to 48 weeks. The pooled meta-analysis demonstrated a significant effect of omega-3 on FMD (WMD = 0.8%, 95% CI = 0.3-1.3, p = .001) and heterogeneity was significant (I2  = 82.5%, p < .001).

CONCLUSION

We found that n-3 PUFA supplementation improves endothelial function as estimated by flow-mediated dilatation of the brachial artery.

Effects of marine-derived n-3 PUFA supplementation on soluble adhesion molecules: A systematic review and dose-response meta-analysis of randomized controlled trials

Long-chain n-3 poly unsaturated fatty acids have anti-inflammatory effects but their effects on serum levels of adhesion molecules are inconsistent and contradictory. In this updated systematic review and meta-analysis, marine sources of omega-3 fatty acids were pooled up to determine the effects of omega-3 supplementation on adhesion molecules. PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases (from inception to April 2023) were searched and all RCTs investigating the effects of marine sources of omega-3, on blood concentrations of adhesion molecules were included and a meta-analysis undertaken. Forty-two RCTs were included involving 3555 participants aged from 18 to 75 years. Meta-analysis of 38 arms from 30 RCTs reporting serum concentrations of vascular cell adhesion molecule-1 (VCAM-1) showed a significant reduction after omega-3 supplementation (WMD: -1.26, 95% CI: -1.88 to -0.64 ng/mL, P < 0.001). Meta-analysis of 40 arms from 30 RCTs reporting serum concentrations of intercellular adhesion molecule-1 (ICAM-1) revealed a reduction following omega-3 supplementation, although it was not significant (WMD: -1.76, 95%CI: -3.68 to 0.16 ng/mL, P = 0.07). Meta-analysis of 27 arms from 21 trials showed no effect on E-selectin (WMD: 0.01, 95%CI: -0.02 to 0.04 ng/mL, P = 0.62). Pooling 15 arms from 11 RCTs showed a marginally significant reducing effect on P-selectin concentrations (WMD: -2.67, 95%CI: -5.53 to 0.19 ng/mL, P = 0.06). A considerable decrease in VCAM concentration was observed after omega-3 supplementation in this meta-analysis with a trend to decreases in both ICAM and P-selectin levels, with effects that may be significant depending on study design, and there was no effect on E-selectin.

Effects of Omega-3 Fatty Acids on Flow-mediated Dilatation and Carotid Intima Media Thickness: A Meta-analysis

PURPOSE OF REVIEW

To investigate the effects of omega-3 fatty acids on flow-mediated dilatation (FMD) and carotid intima-media thickness (CIMT) and explore the factors influencing these effects.

RECENT FINDINGS

FMD was significantly higher in the omega-3 fatty acid group compared to the control group (mean difference = 0.90%; p = 0.0003). In particular, the subgroup with CHD (both EPA + DHA < 1 g/day and ≥ 1 g/day) and the subgroup without CHD but with CHD risk factors (only EPA + DHA ≥ 1 g/day) showed significantly increased FMD after supplementation of omega-3 fatty acids. CIMT was not significantly different between the omega-3 fatty acid and control groups (standardized mean difference = -0.08; p = 0.26). Subgroup analysis of CHD patients was not conducted because of the limited number of studies. Intake of omega-3 fatty acids improved FMD in patients with CHD and patients with risk factors for CHD. Further research is needed on the effects of omega-3 fatty acids on CIMT.

Effects of dietary adjustment of n-3:n-6 fatty-acid ratio to 1:2 on anti-inflammatory and insulin-signaling pathways in ovariectomized mice with high fat diet-induced obesity

Estrogen deficiency increases the secretion of inflammatory mediators and can lead to obesity. Consequently, estrogen deficiency can cause metabolic syndrome, particularly insulin resistance during menopause. Both fish oil and perilla oil contain n-3 fatty acids, which may regulate several inflammatory cytokines. Additionally, adjusting the dietary n-3:n-6 fatty-acid ratio to 1:2 may help treat or prevent chronic diseases. Therefore, we investigated the effect of anti-inflammatory and insulin-signaling pathways, not solely in relation to the (n-3:n-6 fatty-acid ratio at 1:2), but also considering the origin of n-3 fatty acids found in fish oil and perilla oil, in a mouse model of estrogen deficiency induced by ovariectomy and obesity induced by a high-fat diet (HFD). Female C57BL/6J mice were divided into five groups: sham mice on a normal diet; ovariectomized (OVX) mice on a normal diet (OC); OVX mice on a HFD plus lard oil (OL), fish oil (OF), or perilla oil (OP). The dietary n-3:n-6 ratio in the OF and OP groups was adjusted to 1:2. The results showed OF group exhibited significantly lower abdominal adipose tissue weight, fewer liver lipid droplets, and smaller uterine adipocytes, compared with the OL group. Compared with the OL group, the OF and OP groups exhibited higher oral glucose tolerance and lower serum alanine aminotransferase activity, triacylglycerol levels, and total cholesterol levels. Hepatic JAK2, STAT3, and SOCS3 mRNA expression and p-NF-κB p65 and IL-6 levels were significantly lower in the OF and OP groups than in the OL group. Only the OF group exhibited an increase in PI3K and Akt mRNA expression, decrease in GLUT2 mRNA expression, and considerable elevation of p-Akt. Both fish and perilla oil reduced inflammatory signaling markers. However, only fish oil improved insulin signaling (PI3K, Akt, and GLUT2). Our data suggest that fish oil can alleviate insulin signaling through activating the PI3K-Akt-GLUT2 cascade signaling pathway.

Higher docosahexaenoic acid levels lower the protective impact of eicosapentaenoic acid on long-term major cardiovascular events

Introduction

Long-chain omega-3 polyunsaturated fatty acids (OM3 PUFA) are commonly used for cardiovascular disease prevention. High-dose eicosapentaenoic acid (EPA) is reported to reduce major adverse cardiovascular events (MACE); however, a combined EPA and docosahexaenoic acid (DHA) supplementation has not been proven to do so. This study aimed to evaluate the potential interaction between EPA and DHA levels on long-term MACE.

Methods

We studied a cohort of 987 randomly selected subjects enrolled in the INSPIRE biobank registry who underwent coronary angiography. We used rapid throughput liquid chromatography-mass spectrometry to quantify the EPA and DHA plasma levels and examined their impact unadjusted, adjusted for one another, and fully adjusted for comorbidities, EPA + DHA, and the EPA/DHA ratio on long-term (10-year) MACE (all-cause death, myocardial infarction, stroke, heart failure hospitalization).

Results

The average subject age was 61.5 ± 12.2 years, 57% were male, 41% were obese, 42% had severe coronary artery disease (CAD), and 311 (31.5%) had a MACE. The 10-year MACE unadjusted hazard ratio (HR) for the highest (fourth) vs. lowest (first) quartile (Q) of EPA was HR = 0.48 (95% CI: 0.35, 0.67). The adjustment for DHA changed the HR to 0.30 (CI: 0.19, 0.49), and an additional adjustment for baseline differences changed the HR to 0.36 (CI: 0.22, 0.58). Conversely, unadjusted DHA did not significantly predict MACE, but adjustment for EPA resulted in a 1.81-fold higher risk of MACE (CI: 1.14, 2.90) for Q4 vs. Q1. However, after the adjustment for baseline differences, the risk of MACE was not significant for DHA (HR = 1.37; CI: 0.85, 2.20). An EPA/DHA ratio ≥1 resulted in a lower rate of 10-year MACE outcomes (27% vs. 37%, adjusted p-value = 0.013).

Conclusions

Higher levels of EPA, but not DHA, are associated with a lower risk of MACE. When combined with EPA, higher DHA blunts the benefit of EPA and is associated with a higher risk of MACE in the presence of low EPA. These findings can help explain the discrepant results of EPA-only and EPA/DHA mixed clinical supplementation trials.

The Potential Cardiometabolic Effects of Long-Chain ω-3 Polyunsaturated Fatty Acids: Recent Updates and Controversies

Various health-related effects of long-chain (LC) ω-3 PUFAs, EPA, and DHA have been suggested. LC ω-3 PUFAs reduce TG concentrations and have anti-inflammatory, immunomodulatory, antiplatelet, and vascular protective effects. Controversially, they might help in restoring glucose homeostasis via the gut microbiota. However, previous studies have not shown the clear benefits of LC ω-3 PUFAs for CVDs. REDUCE-IT and STRENGTH-representative randomized controlled trials (RCTs) that examined whether LC ω-3 PUFAs would prevent major adverse cardiovascular (CV) events (MACE)-showed conflicting results with differences in the types, doses, or comparators of LC ω-3 PUFAs and study populations. Therefore, we performed a meta-analysis using major RCTs to address this inconsistency and assess the clinical and biological effects of LC ω-3 PUFAs. We included RCTs that involved ≥500 participants with ≥1 y follow-up. Of 17 studies involving 143,410 people, LC ω-3 PUFA supplementation showed beneficial effects on CV death (RR: 0.94; 95% CI: 0.88, 0.99; P = 0.029) and fatal or nonfatal MI (RR: 0.83; 95% CI: 0.72, 0.95; P = 0.010). RCTs on EPA alone showed better results for 3-point MACE, CV death, and fatal or nonfatal MI. However, the benefits were not found for fatal or nonfatal stroke, all-cause mortality, and hospitalization for heart failure. Of note, studies of both the EPA/DHA combination and EPA alone showed a significant increase in risk of new-onset atrial fibrillation. Thus, well-designed studies are needed to investigate the underlying mechanisms involved in the distinct effects of EPA compared with DHA on cardiometabolic diseases. This review discusses the potential benefits and safety of LC ω-3 PUFAs from a cardiometabolic perspective focusing on recent updates and controversies.

Omega-3 Fatty Acids in Cardiovascular Disease and Diabetes: a Review of Recent Evidence

PURPOSE OF REVIEW

Omega-3 fatty acids (n-3 FA) lower triglycerides, have anti-inflammatory properties, and improve metabolism. Clinical evidence of cardiovascular benefit with omega-3 fatty acids is mixed. We discuss mechanisms providing biological plausibility of benefit of omega-3 fatty acids in cardiovascular risk reduction and review clinical trials investigating the benefits of prescription omega-3 fatty acids in dyslipidemia, atherosclerotic cardiovascular disease (ASCVD), and diabetes.

RECENT FINDINGS

Although early trials showed no benefit of omega-3 fatty acids in ASCVD, the REDUCE-IT trial noted significant risk reduction in ASCVD events with highly purified EPA (icosapent ethyl) use which has changed the landscape for currently available therapeutic options. However, other large trials like STRENGTH and VITAL, which used different formulations of prescription omega-3 fatty acids, did not note significant cardiovascular risk reduction. Thus the effectiveness of omega-3 fatty acids for cardiovascular disease prevention is an ongoing topic of debate. A relative paucity of studies examining benefits for glycemic outcomes in persons with diabetes exists; however, few studies have suggested lack of benefit to date. Significant residual cardiovascular risk exists for individuals with hypertriglyceridemia. Prescription omega-3 fatty acids are more commonly used for CV risk reduction in these patients. Clinical guideline statements now recommend icosapent ethyl use for selected individuals with hypertriglyceridemia to reduce cardiovascular events given recent evidence from the REDUCE-IT trial. Nonetheless, data from other large scale trials has been mixed, and future research is needed to better understand how different preparations of omega-3 may differ in their cardiovascular and metabolic effects, and the mechanisms for their benefit.

Pros and Cons of Long-Chain Omega-3 Polyunsaturated Fatty Acids in Cardiovascular Health

The long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are found in seafood, supplements, and concentrated pharmaceutical preparations. Prospective cohort studies demonstrate an association between higher intakes of EPA+DHA or higher levels of EPA and DHA in the body and lower risk of developing cardiovascular disease (CVD), especially coronary heart disease and myocardial infarction, and of cardiovascular mortality in the general population. The cardioprotective effect of EPA and DHA is due to the beneficial modulation of a number of risk factors for CVD. Some large trials support the use of EPA+DHA (or EPA alone) in high-risk patients, although the evidence is inconsistent. This review presents key studies of EPA and DHA in the primary and secondary prevention of CVD, briefly describes potential mechanisms of action, and discusses recently published RCTs and meta-analyses. Potential adverse aspects of long-chain omega-3 fatty acids in relation to CVD are discussed.

Effects of omega-3 supplementation on endothelial function, vascular structure, and metabolic parameters in adolescents with type 1 diabetes mellitus: A randomized clinical trial

Background

Vascular dysfunction is a major complication of diabetes mellitus that leads to cardiovascular disease (CVD). This study aimed to examine the effects of omega-3 consumption on endothelial function, vascular structure, and metabolic parameters in adolescents with type 1 diabetes mellitus (T1DM).

Methods

In this randomized, double-blind, placebo-controlled clinical trial, 51 adolescents (10–18 years) with T1DM completed the study. Patients received 600 mg/day [containing 180 mg eicosapentaenoic acid (EPA) and 120 mg docosahexaenoic acid (DHA)] of omega-3 or placebo for 12 weeks. Flow-mediated dilation (FMD), carotid intima-media thickness (CIMT), high-sensitivity C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol, blood urea nitrogen (BUN), creatinine, fasting blood sugar (FBS), hemoglobin A1C (HbA1c), homeostatic model assessment for insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), serum insulin (SI), urine albumin-creatinine ratio (uACR), blood pressure, and anthropometric indices were assessed at the baseline and after the intervention.

Results

Following supplementation, omega-3 significantly increased FMD (3.1 ± 4.2 vs. −0.6 ± 4%, p = 0.006) and decreased TG (−7.4 ± 10.7 vs. −0.1 ± 13.1 mg/dl, p = 0.022) in comparison with the placebo group. However, no significant difference was observed regarding CIMT (-0.005 ± 0.036 vs. 0.003 ± 0.021 mm, p = 0.33). Although hs-CRP was significantly decreased within the omega-3 group (p = 0.031); however, no significant change was observed compared to placebo group (p = 0.221). Omega-3 supplementation had no significant effect on other variables.

Conclusion

Given the elevation in FMD and reduction in TG, omega-3 supplementation can improve vascular function and may reduce the risk of cardiovascular disease in adolescents with T1DM patients.

Omega-3 fatty acids, subclinical atherosclerosis, and cardiovascular events: Implications for primary prevention

BACKGROUND AND AIMS

High-dose eicosapentaenoic acid (EPA) therapy was beneficial in high-risk patients without clinical cardiovascular disease (CVD). Whether higher plasma levels of EPA and docosahexaenoic acid (DHA) have similar benefits in those without subclinical CVD is unclear. We aim to evaluate the interplay between plasma omega-3 fatty acids and coronary artery calcium (CAC) in relation to CVD events.

METHODS

We examined 6568 participants from the Multi-Ethnic Study of Atherosclerosis (MESA) with plasma EPA and DHA levels and CAC measured at baseline. The primary outcome was incident CVD events (myocardial infarction, angina, cardiac arrest, stroke, CVD death). Hazard ratios for the primary outcome were adjusted for potential confounder using Cox regression.

RESULTS

Mean ± SD age was 62.1 ± 10.2 years and 52.9% were females. The median follow-up time was 15.6 years. Higher loge(EPA) (adjusted hazard ratio, aHR = 0.83; 95% CI, 0.74-0.94) and loge(DHA) (aHR = 0.79; 95% CI, 0.66-0.96) were independently associated with fewer CVD events. The difference in absolute CVD event rates between lowest vs. highest EPA tertile increased at higher CAC levels. The adjusted HR for highest vs. lowest EPA tertile within CAC = 0 was 1.02 (95% CI, 0.72-1.46), CAC = 1-99 was 0.71 (95% CI, 0.51-0.99), and CAC≥100 was 0.67 (95% CI, 0.52-0.84). A similar association was seen in tertiles of DHA by CAC category.

CONCLUSIONS

In an ethnically diverse population free of clinical CVD, higher plasma omega-3 fatty acid levels were associated with fewer long-term CVD events. The absolute decrease in CVD events with higher omega-3 fatty acid levels was more apparent at higher CAC scores.

Positive Effects of Extra-Virgin Olive Oil Supplementation and DietBra on Inflammation and Glycemic Profiles in Adults With Type 2 Diabetes and Class II/III Obesity: A Randomized Clinical Trial

Background

Evidence on the effects of dietary interventions on inflammatory markers in individuals with obesity and type 2 diabetes mellitus (T2DM) is scarce. Our study evaluated the effects of extra-virgin olive oil alone and in combination with a traditional Brazilian diet on inflammatory markers and glycemic profiles in adults with both T2DM and class II/III obesity.

Methods

Adults aged 18-64 years with T2DM and class II/III obesity were randomized into two intervention groups: 1) extra-virgin olive oil only and 2) extra-virgin olive oil + a traditional Brazilian diet (OliveOil+DietBra). Data on sociodemographic characteristics, lifestyle, anthropometry, biochemical markers and inflammatory markers were collected. The primary outcomes were glycemic parameters and inflammatory markers. The body mass index (BMI) and weight were the secondary outcomes.

Results

Forty individuals with T2DM and class II/III obesity were enrolled, and 34 (85%) completed the intervention course. The intake of olive oil was 37.88 ± 12.50 mL/day in the olive oil group and 37.71 ± 12.23 mL/day in the OliveOil+DietBra group, with no significant difference between groups (p = 0.484). Compared to the olive oil only group, the OliveOil+DietBra group had significantly lower levels of fasting insulin (p = 0.047) at the end of the intervention, whereas the other glycemic parameters were not altered. In the OliveOil+DietBra group, serum levels of inflammatory cytokines, IL-1α (p = 0.006) and adiponectin (p = 0.049) were lower and those of TNFα were higher (p = 0.037). There was a significant reduction in BMI and weight compared to the baseline values in the OliveOil+DietBra group (p = 0.015).

Conclusions

The intervention with OliveOil+DietBra effectively decreased the levels of fasting insulin, IL-1α and adiponectin, suggesting its beneficial role in improving the inflammatory profiles and fasting insulin levels in adults with class II/III obesity and T2DM.

Clinical Trial Registration

ClinicalTrials.gov, identifier: NCT02463435.

A Novel Combination of High-Load Omega-3 Lysine Complex (AvailOm®) and Anthocyanins Exerts Beneficial Cardiovascular Effects

Omega-3 fatty acids have been shown to exert several beneficial effects in the prevention of cardiovascular and cerebrovascular diseases. The objective of the present study was to analyze the effects of a novel high-load omega-3 lysine complex, AvailOm^®, its related constituents and a novel mixture of AvailOm^® with specific vasoactive anthocyanins on vascular function in mice resistance artery. Pressure myograph was used to perform vascular reactivity studies. Nitric oxide and oxidative stress were assessed by difluorofluorescein diacetate and dihydroethidium, respectively. Increasing doses of AvailOm^® exerted a dose-response vasorelaxation via AMPK-eNOS-mediated signaling. Omega-3 Ethyl Ester was identified as the main bioactive derivative of AvailOm^®, being capable of inducing vasorelaxant action to the same extent of entire product. The combination of AvailOm^® with a mix of potent vasoactive anthocyanins (C3-glu + DP3-glu + Mal3-glu + Mal3-gal + PEO3-gal), strongly protected mesenteric arteries from vascular dysfunction and oxidative stress evoked by oxidized-LDL. These data demonstrate for the first time the direct effects of AvailOm^® on resistance arteries. The evidence that the combination of specific vasoactive anthocyanins and AvailOm^® further enhanced the vasculoprotective properties of these compounds, may offer new promising perspectives for preventing the onset of cardiovascular and cerebrovascular events.

Effects of DHA-Rich n-3 Fatty Acid Supplementation and/or Resistance Training on Body Composition and Cardiometabolic Biomarkers in Overweight and Obese Post-Menopausal Women

Resistance training (RT) and n-3 polyunsaturated fatty acids (n-3 PUFA) supplementation have emerged as strategies to improve muscle function in older adults. Overweight/obese postmenopausal women (55–70 years) were randomly allocated to one of four experimental groups, receiving placebo (olive oil) or docosahexaenoic acid (DHA)-rich n-3 PUFA supplementation alone or in combination with a supervised RT-program for 16 weeks. At baseline and at end of the trial, body composition, anthropometrical measures, blood pressure and serum glucose and lipid biomarkers were analyzed. Oral glucose tolerance tests (OGTT) and strength tests were also performed. All groups exhibit a similar moderate reduction in body weight and fat mass, but the RT-groups maintained bone mineral content, increased upper limbs lean mass, decreased lower limbs fat mass, and increased muscle strength and quality compared to untrained-groups. The RT-program also improved glucose tolerance (lowering the OGTT incremental area under the curve). The DHA-rich supplementation lowered diastolic blood pressure and circulating triglycerides and increased muscle quality in lower limbs. In conclusion, 16-week RT-program improved segmented body composition, bone mineral content, and glucose tolerance, while the DHA-rich supplement had beneficial effects on cardiovascular health markers in overweight/obese postmenopausal women. No synergistic effects were observed for DHA supplementation and RT-program combination.

Omega-3 Fatty Acids and Coronary Artery Disease: More Questions Than Answers

Studies show that patients with elevated triglycerides and well-controlled LDL levels under statin therapy still have a significant residual risk of cardiovascular (CV) events. Despite many attempts to reduce triglycerides with different hypolipidemic drugs, no therapeutic option has given satisfactory results so far. The initial enthusiasm that omega-3 fatty acids can effectively reduce triglycerides and CV risk was replaced with skepticism when the first large clinical trials failed to show any benefit in primary or secondary prevention. However, the latest studies succeeded in showing a positive effect of omega-3 fatty acids on CV outcome in patients with hypertriglyceridemia. The largest benefit was reported in secondary but not primary prevention. Interestingly, the reduction in triglycerides in some of these studies was disproportionately low to the relatively high CV risk reduction, which could indicate some other effects of omega-3 fatty acids that go well beyond hypotriglyceridemic action. This includes blood pressure reduction, antithrombotic effect, improvement of inflammatory status, endothelial function, and insulin resistance. Investigations also reported a significant and positive influence of omega-3 fatty acids on the composition and stabilization of coronary atherosclerotic plaques in patients with and without previous CV events. In addition to insufficiently known mechanisms of action and conflicting results about the effectiveness of omega-3 fatty acids, the safety problems, which include increased prevalence of atrial fibrillation and hemorrhage, were also reported. The aim of this clinical review was to summarize the current knowledge regarding the use of omega-3 fatty acids in CV patients, particularly those with coronary artery disease, and to present an overview of key clinical trial data.

DHA 12-LOX-derived oxylipins regulate platelet activation and thrombus formation through a PKA-dependent signaling pathway

BACKGROUND

The effects of docosahexaenoic acid (DHA) on cardiovascular disease are controversial and a mechanistic understanding of how this omega-3 polyunsaturated fatty acid (ω-3 PUFA) regulates platelet reactivity and the subsequent risk of a thrombotic event is warranted. In platelets, DHA is oxidized by 12-lipoxygenase (12-LOX) producing the oxidized lipids (oxylipins) 11-HDHA and 14-HDHA. We hypothesized that 12-LOX DHA-oxylipins may be involved in the beneficial effects observed in dietary supplemental treatment with ω-3 PUFAs or DHA itself.

OBJECTIVES

To determine the effects of DHA, 11-HDHA, and 14-HDHA on platelet function and thrombus formation, and to elucidate the mechanism by which these ω-3 PUFAs regulate platelet activation.

METHODS AND RESULTS

DHA, 11-HDHA, and 14-HDHA attenuated collagen-induced human platelet aggregation, but only the oxylipins inhibited ⍺IIbβ3 activation and decreased ⍺-granule secretion. Furthermore, treatment of whole blood with DHA and its oxylipins impaired platelet adhesion and accumulation to a collagen-coated surface. Interestingly, thrombus formation was only diminished in mice treated with 11-HDHA or 14-HDHA, and mouse platelet activation was inhibited following acute treatment with these oxylipins or chronic treatment with DHA, suggesting that under physiologic conditions, the effects of DHA are mediated through its oxylipins. Finally, the protective mechanism of DHA oxylipins was shown to be mediated via activation of protein kinase A.

CONCLUSIONS

This study provides the first mechanistic evidence of how DHA and its 12-LOX oxylipins inhibit platelet activity and thrombus formation. These findings support the beneficial effects of DHA as therapeutic intervention in atherothrombotic diseases.

Effects of Omega-3 Polyunsaturated Fatty Acids and Their Metabolites on Haemostasis-Current Perspectives in Cardiovascular Disease

The beneficial effects of long-chain polyunsaturated omega-3 fatty acids (omega-3 PUFAs) in cardioprotection are widely known and generally accepted. In this literature review, we have focused on the known and postulated mechanisms of action of omega-3 PUFAs and their metabolites on various components of the haemostatic system, in particular on blood platelets and endothelium. We have also made an attempt to provide a comprehensive review of epidemiological studies with particular regard to clinical trials. Notably, the results of these studies are contradictory, and some of them failed to report the beneficial effects of taking or supplementing omega-3 PUFAs in the diet. A potential explanation, in our opinion, could be the need to use higher doses of omega-3 PUFAs and a proper ratio of omega-3 and omega-6 PUFAs. An additional problem which is difficult to solve is the use of a proper neutral placebo for interventional studies. Despite some controversies regarding the beneficial effects of supplementation of omega-3 PUFAs in cardiovascular disease, our review suggests that a promising aspect of future studies and applications is to focus on the anti-thrombotic properties of these compounds. An argument supporting this assumption is the recent use of omega-3 PUFAs as a supporting tool for the treatment of COVID-19 complications.

Cardiovascular effects of omega-3 fatty acids: Hope or hype?

Omega-3 fatty acids have emerged as a new option for controlling the residual risk for cardiovascular disease (CVD) in the statin era after a clinical trial (REDUCE-IT) reported positive results with icosapent ethyl (IPE) in patients receiving maximally tolerated statin therapy. However, another trial which used high dose eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) combination (STRENGTH) has failed. Together, these results raise clinically important questions. Are effects of omega-3 fatty acids neutral or beneficial in patients on statin therapy, or perhaps even harmful? The current contradictory results could be attributed to different types of omega-3 fatty acids (only EPA or combination of EPA + DHA), doses (higher vs. lower dose) of omega-3 fatty acids or different comparators (corn oil or mineral oil), as well as the underlying severity of the CVD risk or use of statins. Together with these issues, we will discuss different biological and clinical effects of various types of omega-3 fatty acids and then interpret different results of past and current clinical studies and propose practical suggestions, which could be applied in patient management.

Micronutrients, Phytochemicals and Mediterranean Diet: A Potential Protective Role against COVID-19 through Modulation of PAF Actions and Metabolism

The new coronavirus disease 2019 (COVID-19) pandemic is an emerging situation with high rates of morbidity and mortality, in the pathophysiology of which inflammation and thrombosis are implicated. The disease is directly connected to the nutritional status of patients and a well-balanced diet is recommended by official sources. Recently, the role of platelet activating factor (PAF) was suggested in the pathogenesis of COVID-19. In the present review several micronutrients (vitamin A, vitamin C, vitamin E, vitamin D, selenium, omega-3 fatty acids, and minerals), phytochemicals and Mediterranean diet compounds with potential anti-COVID activity are presented. We further underline that the well-known anti-inflammatory and anti-thrombotic actions of the investigated nutrients and/or holistic dietary schemes, such as the Mediterranean diet, are also mediated through PAF. In conclusion, there is no single food to prevent coronavirus Although the relationship between PAF and COVID-19 is not robust, a healthy diet containing PAF inhibitors may target both inflammation and thrombosis and prevent the deleterious effects of COVID-19. The next step is the experimental confirmation or not of the PAF-COVID-19 hypothesis.

Effect of Differently Fed Farmed Gilthead Sea Bream Consumption on Platelet Aggregation and Circulating Haemostatic Markers among Apparently Healthy Adults: A Double-Blind Randomized Crossover Trial

Fish consumption beneficially affects coagulation markers. Few dietary intervention studies have investigated differently fed farmed fish against these cardio-metabolic risk factors in humans. This double-blind randomized crossover trial evaluated differently fed farmed gilthead sea bream consumption against platelet aggregation and circulating haemostatic markers among apparently healthy adults. Subjects aged 30-65 years, with a body mass index 24.0-31.0 kg/m², consuming less than 150 g cooked fish per week, were recruited in Attica, Greece. Participants were randomized (n = 38, 1:1) to one of two sequences; consumption of fish fed with fish oil diet (conventional fish, CF)/fish fed with olive pomace-enriched diet (enriched fish, EF) versus EF/CF. The primary outcomes were ex vivo human platelet aggregation and circulating plasminogen activator inhibitor-1 (PAI-1) and P-selectin (sP-selectin) concentrations. EF consumption had no significant effect on platelet sensitivity or haemostatic markers compared to CF. Platelet sensitivity to platelet-activating factor (PAF) decreased after CF consumption during the second period (p < 0.01). Plasma PAI-1 and sP-selectin concentrations increased after CF consumption during both periods (p < 0.01 for both). Based on current findings, consumption of enriched farmed gilthead sea bream had no greater effect on coagulation markers in adults compared to the conventionally fed fish.

The ratio of eicosapentaenoic acid to docosahexaenoic acid as a modulator for the cardio-metabolic effects of omega-3 supplements: A meta-regression of randomized clinical trials

BACKGROUND

A large number of studies have demonstrated the effects of omega- 3 supplements containing mixtures of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), known to favorably affect many modifiable risk factors of coronary heart disease (CHD). These studies have used diverse ratios and doses of EPA and DHA. However, it is not known whether the ratio of EPA to DHA in omega-3 supplements affect their efficacy as modulators for cardiovascular risk factors. This meta-regression aimed to investigate the effect of different ratios of EPA to DHA on risk factors associated with CHD including lipid profile, blood pressure, heart rate, and inflammation.

METHOD

A regression analysis was carried out on 92 clinical trials with acceptable quality (Jadad score ≥ 3) that were previously identified from two databases (PubMed and Cochrane Library).

RESULTS

Data from studies that met the inclusion criteria for this analysis showed that the ratio of EPA to DHA was not associated with lipid profile, diastolic blood pressure, or heart rate. With all studies, the ratio of EPA to DHA was associated with C-reactive protein (CRP) (β = -1.3121 (95 % CI: -1.6610 to -0.9543), that is, the higher the EPA to DHA ratio, the greater the reduction. Using only studies that supplied EPA and DHA in the range of 2 g-6 g, the ratio of EPA to DHA was also associated with CRP (β = -2.10429 and 95 % CI: -3.89963 to -0.30895); that is, an even more pronounced reduction in CRP with a higher EPA to DHA ratio. Systolic blood pressure was only associated with an increasing EPA to DHA ratio in the 2 g-6 g range (β = 5.47129 and 95 % CI: 0.40677-10.53580), that is, a higher EPA to DHA ratio within this dose range, the greater the increase in SBP.

CONCLUSION

Current data suggest that the EPA to DHA ratio only correlates to the modulation of CRP by omega-3 supplementation of EPA and DHA, and SBP in studies that supplemented EPA and DHA in the range of 2 g-6 g, shedding light on potential differential effects of EPA vs. DHA on inflammation and systolic blood pressure.

Omega-3 polyunsaturated fatty acids and hypertension: a review of vasodilatory mechanisms of docosahexaenoic acid and eicosapentaenoic acid

Hypertension is often characterised by impaired vasodilation involving dysfunction of multiple vasodilatory mechanisms. ω-3 polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) can reduce blood pressure and vasodilation. In the endothelium, DHA and EPA improve function including increased NO bioavailability. However, animal studies show that DHA- and EPA-mediated vasodilation persists after endothelial removal, indicating a role for vascular smooth muscle cells (VSMCs). The vasodilatory effects of ω-3 PUFAs on VSMCs are mediated via opening of large conductance calcium-activated potassium channels (BK_Ca ), ATP-sensitive potassium channels (K_ATP ) and possibly members of the K_v 7 family of voltage-activated potassium channels, resulting in hyperpolarisation and relaxation. ω-3 PUFA actions on BK_Ca and voltage-gated ion channels involve electrostatic interactions that are dependent on the polyunsaturated acyl tail, cis-geometry of these double bonds and negative charge of the carboxyl headgroup. This suggests structural manipulation of ω-3 PUFA could generate novel, targeted, therapeutic leads.

Protective Effects of Eicosapentaenoic Acid on the Glomerular Endothelium via Inhibition of EndMT in Diabetes

Diabetes-induced endothelial pathologies are hypothesized to lead to the progression of diabetic kidney disease (DKD). The endothelial to mesenchymal transition (EndMT) possibly induces fibrosis, leading to glomerulosclerosis in the kidney. Furthermore, this could lead to albuminuria in diabetic nephropathy due to glomerular endothelial dysfunction. Eicosapentaenoic acid (EPA), purified from fish oil, decreases inflammatory cytokine levels in glomerulonephritis. Here, we aimed at finding whether ethyl eicosapentaenoate (EPA-E) exerts renal protective effects via EndMT inhibition. To find out whether EPA inhibits EndMT in vitro, the changes in CD31 expression were studied in cultured mouse endothelial cells. The addition of the conditioned medium from the adipocyte culture significantly decreased the protein levels of CD31, while the addition of EPA-E partially reversed this inhibition. Further, EndMT inhibition by EPA-E treatment might occur via the inhibition of the protein kinase Cβ (PKCβ)/transforming growth factor-β (TGF-β)/plasminogen activator inhibitor-1 (PAI-1) signaling and not via microRNAs. Streptozotocin-induced diabetic mice fed a high-fat diet (60% from fat) exhibited mesangial expansion and albuminuria. Induction of EPA-E ameliorated the mesangial expansion and decreased albuminuria without affecting blood pressure, triglyceride and free fatty acid levels, and intraperitoneal glucose. These findings suggest that EPA-E exerts renal protective effects on endothelial cells, by normalizing EndMT followed by the PKCβ/TGF-β/PAI-1 signaling. Thus, EPA-E has the potential for imparting renal protection by regulating EndMT in DKD.

Effect of omega-3 polyunsaturated fatty acids in modulation of vascular tone under physiological and pathological conditions

Omega-3 polyunsaturated fatty acids (n-3 PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are mainly found in marine fish oils and commercially available fish oil supplements. Several studies have documented that n-3 PUFAs can reduce the risk of cardiovascular diseases through anti-inflammatory, anti-thrombotic, and anti-atherosclerotic properties. Notably, regulation of vascular tone is one of the most important bases of cardiovascular health and especially for maintaining blood pressure within optimal physiological ranges. Recent clinical and animal studies indicate an association between n-3 PUFAs and vascular functions. In this regard, many clinical trials and basic experimental studies have been conducted so far to investigate the influence of n-3 PUFAs on vascular tone. In this review, we have summarized the results obtained from both clinical and basic studies that evaluated the effect of n-3 PUFAs under physiological and pathological conditions. Moreover, we also focus on verifying the underlying basic molecular mechanism of n-3 PUFAs on the vascular system.

Omega-3 polyunsaturated fatty acid supplementation versus placebo on vascular health, glycaemic control, and metabolic parameters in people with type 1 diabetes: a randomised controlled preliminary trial

Background

The role of omega-3 polyunsaturated fatty acids (n-3PUFA), and the potential impact of n-3PUFA supplementation, in the treatment and management of type 1 diabetes (T1D) remains unclear and controversial. Therefore, this study aimed to examine the efficacy of daily high-dose-bolus n-3PUFA supplementation on vascular health, glycaemic control, and metabolic parameters in subjects with T1D.

Methods

Twenty-seven adults with T1D were recruited to a 6-month randomised, double-blind, placebo-controlled trial. Subjects received either 3.3 g/day of encapsulated n-3PUFA or encapsulated 3.0 g/day corn oil placebo (PLA) for 6-months, with follow-up at 9-months after 3-month washout. Erythrocyte fatty acid composition was determined via gas chromatography. Endpoints included inflammation-associated endothelial biomarkers (vascular cell adhesion molecule-1 [VCAM-1], intercellular adhesion molecule-1 [ICAM-1], E-selectin, P-selectin, pentraxin-3, vascular endothelial growth factor [VEGF]), and their mediator tumor necrosis factor alpha [TNFα] analysed via immunoassay, vascular structure (carotid intima-media thickness [CIMT]) and function (brachial artery flow mediated dilation [FMD]) determined via ultrasound technique, blood pressure, glycosylated haemoglobin (HbA1c), fasting plasma glucose (FPG), and postprandial metabolism.

Results

Twenty subjects completed the trial in full. In the n-3PUFA group, the mean ± SD baseline n-3PUFA index of 4.93 ± 0.94% increased to 7.67 ± 1.86% (P < 0.001) after 3-months, and 8.29 ± 1.45% (P < 0.001) after 6-months. Total exposure to n-3PUFA over the 6-months (area under the curve) was 14.27 ± 3.05% per month under n-3PUFA, and 9.11 ± 2.74% per month under PLA (P < 0.001). VCAM-1, ICAM-1, E-selectin, P-selectin, pentraxin-3, VEGF, TNFα, CIMT, FMD, blood pressure, HbA1c, FPG, and postprandial metabolism did not differ between or within groups after treatment (P > 0.05).

Conclusions

This study indicates that daily high-dose-bolus of n-3PUFA supplementation for 6-months does not improve vascular health, glucose homeostasis, or metabolic parameters in subjects with T1D. The findings from this preliminary RCT do not support the use of therapeutic n-3PUFA supplementation in the treatment and management of T1D and its associated complications.

Trial Registration ISRCTN, ISRCTN40811115. Registered 27 June 2017, http://www.isrctn.com/ISRCTN40811115.

Emerging Mechanisms of Cardiovascular Protection for the Omega-3 Fatty Acid Eicosapentaenoic Acid

Patients with well-controlled LDL (low-density lipoprotein) levels still have residual cardiovascular risk associated with elevated triglycerides. Epidemiological studies have shown that elevated fasting triglyceride levels associate independently with incident cardiovascular events, and abundant recent human genetic data support the causality of TGRLs (triglyceride-rich lipoproteins) in atherothrombosis. Omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), lower blood triglyceride concentrations but likely exert additional atheroprotective properties at higher doses. Omega-3 fatty acids modulate T-cell differentiation and give rise to various prostaglandins and specialized proresolving lipid mediators that promote resolution of tissue injury and inflammation. The REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl–Intervention Trial) with an EPA-only formulation lowered a composite of cardiovascular events by 25% in patients with established cardiovascular disease or diabetes mellitus and other cardiovascular risk factors. This clinical benefit likely arises from multiple molecular mechanisms discussed in this review. Indeed, human plaques readily incorporate EPA, which may render them less likely to trigger clinical events. EPA and DHA differ in their effects on membrane structure, rates of lipid oxidation, inflammatory biomarkers, and endothelial function as well as tissue distributions. Trials that have evaluated DHA-containing high-dose omega-3 fatty acids have thus far not shown the benefits of EPA alone demonstrated in REDUCE-IT. This review will consider the mechanistic evidence that helps to understand the potential mechanisms of benefit of EPA.

Marine Omega-3 (N-3) Fatty Acids for Cardiovascular Health: An Update for 2020

The omega-3 (n-3) fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are found in seafood (especially fatty fish), supplements and concentrated pharmaceutical preparations. Long-term prospective cohort studies consistently demonstrate an association between higher intakes of fish, fatty fish and marine n-3 fatty acids (EPA + DHA) or higher levels of EPA and DHA in the body and lower risk of developing cardiovascular disease (CVD), especially coronary heart disease (CHD) and myocardial infarction (MI), and cardiovascular mortality in the general population. This cardioprotective effect of EPA and DHA is most likely due to the beneficial modulation of a number of known risk factors for CVD, such as blood lipids, blood pressure, heart rate and heart rate variability, platelet aggregation, endothelial function, and inflammation. Evidence for primary prevention of CVD through randomised controlled trials (RCTs) is relatively weak. In high-risk patients, especially in the secondary prevention setting (e.g., post-MI), a number of large RCTs support the use of EPA + DHA (or EPA alone) as confirmed through a recent meta-analysis. This review presents some of the key studies that have investigated EPA and DHA in the primary and secondary prevention of CVD, describes potential mechanisms for their cardioprotective effect, and evaluates the more recently published RCTs in the context of existing scientific literature.

Inflammation and cardiovascular disease: are marine phospholipids the answer?

This review presents the latest research on the cardioprotective effects of n-3 fatty acids (FA) and n-3 FA bound to polar lipids (PL). Overall, n-3 PL may have enhanced bioavailability and potentially bioactivityversusfree FA and ester forms of n-3 FA.

Modulation of endothelial cell responses and vascular function by dietary fatty acids

Healthy and functional endothelial cells play important roles in maintaining vascular homeostasis, whereas endothelial dysfunction initiates and exacerbates vascular disease progression. Interventional studies with dietary fatty acids have shown that these molecules have varying effects on vascular function. It is hypothesized that the actions of dietary fatty acids on vascular function may be mediated in part through endothelial cells. This review summarizes the results of studies that have examined the acute and chronic effects of dietary fatty acids on endothelial function and vascular properties in humans, as well as the potential mechanisms by which n-3 polyunsaturated fatty acids regulate endothelial function. Altogether, this article provides an extensive review of how fatty acids contribute to vascular function through their ability to modulate endothelial cells and discusses relationships between dietary fatty acids and endothelial cells in the context of vascular dysfunction.

The Role of n-3 Fatty Acids in Cardiovascular Disease: Back to the Future

Cardiovascular disease (CVD) remains the major cause of death and disability worldwide, and residual risk after implementing all current therapies is still high. In this context, the latest (2016) European Cardiology Society/European Atherosclerosis Society guidelines recommend that triglyceride (TG)-lowering drugs should be used in high-risk patients with TGs levels >2.3 mmol/L (200 mg/dL), after lifestyle measures fail to lower them. After several neutral CVD outcome trials with n-3 fatty acids, the Reduction of Cardiovascular Events with EPA–Intervention Trial met its primary end point, that is, among patients with elevated TGs levels despite the use of statins, the risk of ischemic events, including cardiovascular death, was significantly lower in those who received 4 g of icosapent ethyl daily. In this review, we comment on the findings of previous and recently published randomized controlled CVD outcome trials assessing n-3 fatty acids supplementation. Both efficacy and safety, as well as future perspectives, are discussed.

Different DHA or EPA production responses to nutrient stress in the marine microalga Tisochrysis lutea and the freshwater microalga Monodus subterraneus

This study investigated the effect of nitrogen (N) and phosphorous (P) stress on the production of DHA or EPA and total fatty acids (TFAs) in the marine microalga Tisochrysis lutea and the freshwater microalga Monodus subterraneus. Five N or P starvation/limitation conditions (N sufficient and P limited, N sufficient and P starved, N starved and P sufficient, N starved and P limited, and N and P starved) and one N and P sufficient condition (control) were studied. The results demonstrated that the proportion of DHA or EPA among TFAs and production in the microalgae suspensions decreased (57%, 73% for N stress and 18%, 51% for P stress, respectively) under N or P stress in both microalgae compared with the N and P sufficient group. Differently, DHA dry weight content of T. lutea decreased significantly, and EPA dry weight content of M. subterraneus decreased slightly under N starved conditions. Clear differences in TFA content/production and the relationship between TFA and DHA or EPA production/content and CO₂ fixation were observed between the two microalgae. These results give a new sight on the difference between marine microalgae and freshwater microalgae. Meanwhile, it gave a potential application to produce DHA or EPA and TFA combining with CO₂ fixation by these microalgae.

In Vitro Antithrombotic Properties of Salmon (Salmo salar) Phospholipids in a Novel Food-Grade Extract

Marine and salmon polar lipids (PLs) extracted by conventional extractions with non-food-grade solvents (CE-salmon-PLs) possess antithrombotic bioactivities against platelet-activating factor (PAF) and thrombin. Similar effects of food-grade-extracted (FGE) marine PLs have not yet been reported. In this study, food-grade solvents were used to extract PLs from Irish organic farmed salmon (Salmo salar) fillets (FGE-salmon-PLs), while their antithrombotic bioactivities were assessed in human platelets induced by platelet aggregation agonists (PAF/thrombin). FGE-salmon-PLs were further separated by thin layer chromatography (TLC) into lipid subclasses, and the antithrombotic bioactivities of each subclass were also assessed. LC-MS was utilized to elucidate the structure-activity relationships. FGE-salmon-PLs strongly inhibited PAF-induced platelet aggregation, while their relevant anti-thrombin effects were at least three times more potent than the previously reported activities of CE-salmon-PLs. TLC-derived lipid fractions corresponding to phosphatidylcholines (PC) and phosphatidylethanolamines (PE) were the most bioactive lipid subclasses obtained, especially against thrombin. Their LC-MS analysis elucidated that they are diacyl- or alkyl-acyl- PC and PE moieties baring ω3 polyunsaturated fatty acids (PUFA) at their sn-2 position, such as eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA). Our results concerning the potent antithrombotic effects of FGE-salmon-PLs against both PAF and thrombin pathways strongly suggest that such food-grade extracts are putative candidates for the development of novel cardioprotective supplements and nutraceuticals.

New insights on the regulation of cancer cachexia by N-3 polyunsaturated fatty acids

Cancer cachexia is a multifactorial syndrome that develops during malignant tumor growth. Changes in plasma levels of several hormones and inflammatory factors result in an intense catabolic state, decreased activity of anabolic pathways, anorexia, and marked weight loss, leading to cachexia development and/or accentuation. Inflammatory mediators appear to be related to the control of a highly regulated process of muscle protein degradation that accelerates the process of cachexia. Several mediators have been postulated to participate in this process, including TNF-α, myostatin, and activated protein degradation pathways. Some interventional therapies have been proposed, including nutritional (dietary, omega-3 fatty acid supplementation), hormonal (insulin), pharmacological (clenbuterol), and nonpharmacological (physical exercise) therapies. Omega-3 (n-3) polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid, are recognized for their anti-inflammatory properties and have been used in therapeutic approaches to treat or attenuate cancer cachexia. In this review, we discuss recent findings on cellular and molecular mechanisms involved in inflammation in the cancer cachexia syndrome and the effectiveness of n-3 PUFAs to attenuate or prevent cancer cachexia.

Plasma polyunsaturated fatty acid profile is associated with vascular endothelial function in patients with type 2 diabetes

Decreased plasma n-3 polyunsaturated fatty acid levels or the n-3/n-6 polyunsaturated fatty acid ratios are associated with a risk of cardiovascular events. In this cross-sectional study, we measured plasma levels of eicosapentaenoic acid, docosahexaenoic acid, and arachidonic acid and investigated the association between the plasma polyunsaturated fatty acid profile and vascular endothelial function in 396 patients with type 2 diabetes. Endothelium-dependent, flow-mediated dilatation of the brachial artery was measured using ultrasonography. Multiple regression analyses, including age, sex, body mass index, and other cardiovascular risk factors, revealed that plasma eicosapentaenoic acid levels ( β = 0.140, p = 0.008) and the eicosapentaenoic acid/arachidonic acid ratio ( β = 0.127, p = 0.019), but not plasma docosahexaenoic acid levels ( β = 0.067, p = 0.220) or the docosahexaenoic acid/arachidonic acid ratio ( β = 0.034, p = 0.559), were independently and positively associated with flow-mediated dilatation. In conclusion, plasma eicosapentaenoic acid levels and the eicosapentaenoic acid/arachidonic acid ratio are independently associated with endothelial function in patients with type 2 diabetes. This study indicates a positive association between eicosapentaenoic acid, rather than docosahexaenoic acid, and endothelial function in type 2 diabetes.

The Role of n-3 Long Chain Polyunsaturated Fatty Acids in Cardiovascular Disease Prevention, and Interactions with Statins

Decreases in global cardiovascular disease (CVD) mortality and morbidity in recent decades can be partly attributed to cholesterol reduction through statin use. n-3 long chain polyunsaturated fatty acids are recommended by some authorities for primary and secondary CVD prevention, and for triglyceride reduction. The residual risk of CVD that remains after statin therapy may potentially be reduced by n-3 long chain polyunsaturated fatty acids. However, the effects of concomitant use of statins and n-3 long chain polyunsaturated fatty acids are not well understood. Pleiotropic effects of statins and n-3 long chain polyunsaturated fatty acids overlap. For example, cytochrome P450 enzymes that metabolize statins may affect n-3 long chain polyunsaturated fatty acid metabolism and vice versa. Clinical and mechanistic study results show both synergistic and antagonistic effects of statins and n-3 long chain polyunsaturated fatty acids when used in combination.

Eicosapentaenoic acid ethyl ester improves endothelial dysfunction in type 2 diabetic mice

Background

Eicosapentaenoic acid (EPA) is thought to have many beneficial effects, such as anti-atherosclerogenic and anti-inflammatory properties. However, few studies have reported its effects of endothelial dysfunction in diabetes and its direct effects on the aorta. Here, we investigated the effects of EPA treatment on impaired endothelium-dependent relaxation of the aorta in KKAy mice, a model of type 2 diabetes.

Methods

Male KKAy mice were fed a high-fat (HF) diet for 8 weeks to induce diabetes, after which they were divided into two groups. One group was fed a HF diet, and the other group was fed a HF diet containing EPA ethyl ester (EPA-E, 10 mg/day) for 4 weeks. Then, the vascular reactivities of prepared aortic rings were measured in an organ bath to determine if EPA-E administration changed vascular function in these diabetic mice. In addition, we examined effect of EPA-E and its metabolites to vascular action using aorta separated from C57BL/6 J mice.

Results

Although EPA-E administration did not change the plasma glucose and insulin levels in diabetic mice, total cholesterol levels were significantly decreased. The aorta extracted from EPA-E untreated diabetic mice showed impaired endothelium-dependent relaxation in response to acetylcholine (ACh). However, EPA-E administration improved the relaxation response to ACh to the control levels observed in non-diabetic C57BL/6 J mice. On the other hand, endothelium-independent relaxation in response to sodium nitroprusside did not significantly differ among these three groups. The enhanced contractile response by phenylephrine in diabetic mice was not altered by the administration of EPA-E. In addition, the direct administration of EPA-E metabolites such as EPA, docosahexaenoic acid, and docosapentaenoic acid led to vasodilation in the aortic rings of C57BL/6 J mice.

Conclusion

These results showed that chronic EPA-E administration prevented the development of endothelial dysfunction in KKAy mice, partly via the direct action of EPA-E metabolites on the aorta.

Omega-3 fatty acids and non-alcoholic fatty liver disease: Evidence of efficacy and mechanism of action

For many years it has been known that high doses of long chain omega-3 fatty acids are beneficial in the treatment of hypertriglyceridaemia. Over the last three decades, there has also been a wealth of in vitro and in vivo data that has accumulated to suggest that long chain omega-3 fatty acid treatment might be beneficial to decrease liver triacylglycerol. Several biological mechanisms have been identified that support this hypothesis; notably, it has been shown that long chain omega-3 fatty acids have a beneficial effect: a) on bioactive metabolites involved in inflammatory pathways, and b) on alteration of nuclear transcription factor activities such as peroxisome proliferator-activated receptors (PPARs), sterol regulatory element-binding protein 1c (SREBP-1c) and carbohydrate-responsive element-binding protein (ChREBP), involved in inflammatory pathways and liver lipid metabolism. Since the pathogenesis of non alcoholic fatty liver disease (NAFLD) begins with the accumulation of liver lipid and progresses with inflammation and then several years later with development of fibrosis; it has been thought in patients with NAFLD omega-3 fatty acid treatment would be beneficial in treating liver lipid and possibly also in ameliorating inflammation. Meta-analyses (of predominantly dietary studies and small trials) have tended to support the assertion that omega-3 fatty acids are beneficial in decreasing liver lipid, but recent randomised controlled trials have produced conflicting data. These trials have suggested that omega-3 fatty acid might be beneficial in decreasing liver triglyceride (docosahexanoic acid also possibly being more effective than eicosapentanoic acid) but not in decreasing other features of steatohepatitis (or liver fibrosis). The purpose of this review is to discuss recent evidence regarding biological mechanisms by which long chain omega-3 fatty acids might act to ameliorate liver disease in NAFLD; to consider the recent evidence from randomised trials in both adults and children with NAFLD; and finally to discuss key 'known unknowns' that need to be considered, before planning future studies that are focussed on testing the effects of omega-3 fatty acid treatment in patients with NAFLD.

Treatment with omega-3 polyunsaturated fatty acids does not improve endothelial function in patients with type 2 diabetes and very high cardiovascular risk: A randomized, double-blind, placebo-controlled study (Omega-FMD)

BACKGROUND AND AIMS

Numerous recent studies conducted in different clinical settings have focused on the benefits of omega-3 polyunsaturated fatty acids (n-3 PUFAs) in the prevention of cardiovascular diseases. There is limited evidence that patients with type 2 diabetes (T2D) and very high cardiovascular risk can also benefit from a high dose of n-3PUFAs, especially those on optimal medical therapy as recommended by the guidelines. The aim of the present study was to assess the impact of high-dose n-3 PUFA treatment on endothelial function in patients with T2D and established atherosclerotic cardiovascular disease (ASCVD).

METHODS

We conducted a prospective randomized double-blind, placebo-controlled, 2-center study, in which endothelial function was measured using flow-mediated dilation (FMD) and nitroglycerin-mediated dilation (NMD). Serum fatty acids composition was measured by gas chromatography. All measurements were done at baseline and after 3 months of treatment with PUFAs at a dose of 2 g/d (n = 36) or placebo (n = 38).

RESULTS

The majority of the study population was treated with optimal medical therapy. Despite significantly higher concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid in the n-3 PUFA group after 3-month treatment, we did not observe significant changes in endothelial function indices (FMD and NMD). However, in regression analysis, only baseline FMD was associated with EPA concentration before 3 months of n-3 PUFA treatment.

CONCLUSIONS

Three months of high-dose n-3 PUFA treatment in very high-risk patients with ASCVD and T2D did not improve the endothelial function indices.

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

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

The Differential Effects of Eicosapentaenoic Acid and Docosahexaenoic Acid on Cardiometabolic Risk Factors: A Systematic Review

A large body of evidence supports the cardioprotective effects of the long-chain omega-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). There is increasing interest in the independent effects of EPA and DHA in the modulation of cardiometabolic risk factors. This systematic review aims to appraise the latest available evidence of the differential effects of EPA and DHA on such risk factors. A systematic literature review was conducted up to May 2017. Randomised controlled trials were included if they met strict eligibility criteria, including EPA or DHA > 2 g/day and purity ≥ 90%. Eighteen identified articles were included, corresponding to six unique studies involving 527 participants. Both EPA and DHA lowered triglyceride concentration, with DHA having a greater triglyceride-lowering effect. Whilst total cholesterol levels were largely unchanged by EPA and DHA, DHA increased high-density lipoprotein (HDL) cholesterol concentration, particularly HDL₂, and increased low-density lipoprotein (LDL) cholesterol concentration and LDL particle size. Both EPA and DHA inhibited platelet activity, whilst DHA improved vascular function and lowered heart rate and blood pressure to a greater extent than EPA. The effects of EPA and DHA on inflammatory markers and glycaemic control were inconclusive; however both lowered oxidative stress. Thus, EPA and DHA appear to have differential effects on cardiometabolic risk factors, but these need to be confirmed by larger clinical studies.

Infrainguinal Lesion of Peripheral Artery Disease and Levels of ω-3 Polyunsaturated Fatty Acids in Peripheral Artery Disease

Background: Recently, reduced serum levels of ω-3 polyunsaturated fatty acids (PUFAs) including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have been focused upon as newly recognized risk factors for peripheral artery disease (PAD). The present study investigated the association between disease location and serum levels of ω-3 PUFAs in patients with PAD. Methods: We retrospectively analyzed the data of patients at Tokyo Medical University between August 2011 and November 2015. The subjects included 98 patients who were categorized into two groups: those with (n=72) and without infrainguinal lesions (n=26). Results: Univariate analysis revealed that low ankle-brachial pressure index (ABI) values, low EPA levels, low DHA levels, low triglyceride levels, and diabetes mellitus were significant risk factors for infrainguinal lesions. Multivariate analysis indicated that low ABI values [p=0.018; odds ratio, 0.043; 95% confidence interval (CI), 0.003-0.579] and low DHA levels (p=0.003; odds ratio, 0.986; 95%CI, 0.977-0.995) were significant independent risk factors for infrainguinal lesions. Conclusion: Our study demonstrated that reduced serum level of DHA may underlie the presence of infrainguinal lesions in patients with PAD.

Phospholipids of Animal and Marine Origin: Structure, Function, and Anti-Inflammatory Properties

In this review paper, the latest literature on the functional properties of phospholipids in relation to inflammation and inflammation-related disorders has been critically appraised and evaluated. The paper is divided into three sections: Section 1 presents an overview of the relationship between structures and biological activities (pro-inflammatory or anti-inflammatory) of several phospholipids with respect to inflammation. Section 2 and Section 3 are dedicated to the structures, functions, compositions and anti-inflammatory properties of dietary phospholipids from animal and marine sources. Most of the dietary phospholipids of animal origin come from meat, egg and dairy products. To date, there is very limited work published on meat phospholipids, undoubtedly due to the negative perception that meat consumption is an unhealthy option because of its putative associations with several chronic diseases. These assumptions are addressed with respect to the phospholipid composition of meat products. Recent research trends indicate that dairy phospholipids possess anti-inflammatory properties, which has led to an increased interest into their molecular structures and reputed health benefits. Finally, the structural composition of phospholipids of marine origin is discussed. Extensive research has been published in relation to ω-3 polyunsaturated fatty acids (PUFAs) and inflammation, however this research has recently come under scrutiny and has proved to be unreliable and controversial in terms of the therapeutic effects of ω-3 PUFA, which are generally in the form of triglycerides and esters. Therefore, this review focuses on recent publications concerning marine phospholipids and their structural composition and related health benefits. Finally, the strong nutritional value of dietary phospholipids are highlighted with respect to marine and animal origin and avenues for future research are discussed.

Coagulation profile of Sudanese children with homozygous sickle cell disease and the effect of treatment with omega-3 fatty acid on the coagulation parameters

Background

It has been reported that patients with SCD do have an abnormal coagulation profile. Coagulopathy is thought to be one of the key factors that contribute to the vaso-occlusive crisis that characterises sickle cell disease (SCD). In this study, we investigated whether Sudanese sickle cell patients have an abnormal coagulation profile. In addition, the effect of treatment with either omega-3 fatty acids or hydroxyurea on coagulation profile was assessed.

Methods

Homozygous SCD patients untreated (n = 52), omega-3 treated (n = 44), hydroxyurea (HU) treated (n = 8) and healthy (HbAA) controls (n = 52) matched for age (4–20 years), gender and socioeconomic status were enrolled. Patients on omega-3 fatty acids, according to age, received one to four capsules containing 277.8 mg DHA and 39.0 mg eicosapentnoic. Patients on Hydroxyurea were in on dosage more than 20 mg/kg/day. The steady state levels of the coagulation parameters and the effect of the treatments with either HU or omega-3 fatty acids on markers of coagulation were investigated.

Results

Compared to the healthy controls, treated and untreated HbSS patients had lower hemoglobin, plasma Protein C, proteins S and higher white blood cell count (WBC), platelets count (PLTs) and plasma D-dimer levels,(p < 0.05). In comparison to untreated HbSS, treatment with neither omega-3 nor HU had effect on the WBC, plasma proteins C and S, (p > 0.05). HU treated group had a lower PLTs count compared to HbSS untreated group (p < 0.5). The prothrombin and activated partial thromboplastin times and international normalized ratio (INR) of untreated patients are significantly higher than n-3 treated, HU-treated patients and health controls, (p < 0.05). Patients treated with omega-3 had lowered D-dimer levels in comparison to HU-treated and untreated HbSS patients, (p < 0.001).

Conclusion

This study provides evidence that Sudanes patients have abnormal coagulation profile and treatment with either HU or omega-3 fatty acids might partially ameliorate SCD-associated chronic coagulopathic state.

Health relevance of the modification of low grade inflammation in ageing (inflammageing) and the role of nutrition

Ageing of the global population has become a public health concern with an important socio-economic dimension. Ageing is characterized by an increase in the concentration of inflammatory markers in the bloodstream, a phenomenon that has been termed "inflammageing". The inflammatory response is beneficial as an acute, transient reaction to harmful conditions, facilitating the defense, repair, turnover and adaptation of many tissues. However, chronic and low grade inflammation is likely to be detrimental for many tissues and for normal functions. We provide an overview of low grade inflammation (LGI) and determine the potential drivers and the effects of the "inflamed" phenotype observed in the elderly. We discuss the role of gut microbiota and immune system crosstalk and the gut-brain axis. Then, we focus on major health complications associated with LGI in the elderly, including mental health and wellbeing, metabolic abnormalities and infections. Finally, we discuss the possibility of manipulating LGI in the elderly by nutritional interventions. We provide an overview of the evidence that exists in the elderly for omega-3 fatty acid, probiotic, prebiotic, antioxidant and polyphenol interventions as a means to influence LGI. We conclude that slowing, controlling or reversing LGI is likely to be an important way to prevent, or reduce the severity of, age-related functional decline and the onset of conditions affecting health and well-being; that there is evidence to support specific dietary interventions as a strategy to control LGI; and that a continued research focus on this field is warranted.