Omega-3 polyunsaturated acids and cardiovascular disease: notable ethnic differences or unfulfilled promise?

Fat and Protein Combat Triggers Immunological Weapons of Innate and Adaptive Immune Systems to Launch Neuroinflammation in Parkinson's Disease

Parkinson's disease (PD) is the second-most common neurodegenerative disease in the world, affecting up to 10 million people. This disease mainly happens due to the loss of dopaminergic neurons accountable for memory and motor function. Partial glucocerebrosidase enzyme deficiency and the resultant excess accumulation of glycosphingolipids and alpha-synuclein (α-syn) aggregation have been linked to predominant risk factors that lead to neurodegeneration and memory and motor defects in PD, with known and unknown causes. An increasing body of evidence uncovers the role of several other lipids and their association with α-syn aggregation, which activates the innate and adaptive immune system and sparks brain inflammation in PD. Here, we review the emerging role of a number of lipids, i.e., triglyceride (TG), diglycerides (DG), glycerophosphoethanolamines (GPE), polyunsaturated fatty acids (PUFA), sphingolipids, gangliosides, glycerophospholipids (GPL), and cholesterols, and their connection with α-syn aggregation as well as the induction of innate and adaptive immune reactions that trigger neuroinflammation in PD.

Bioequivalence of long-chain omega-3 polyunsaturated fatty acids from foods enriched with a novel vegetable-based omega-3 delivery system compared to gel capsules: a randomized controlled cross-over acute trial

Purpose

To evaluate bioavailability of omega-3 long-chain polyunsaturated fatty acids (LCPUFA) from foods enriched with novel vegetable-based encapsulated algal oil across Australian and Singaporean populations.

Methods

27 men (n = 12 Australian European; n = 15 Singaporean Chinese), 21–50 yr; 18–27.5 kg/m², with low habitual intake of omega-3 LCPUFA completed a multicentre randomised controlled acute 3-way cross-over single-blind trial. They consumed, in random order 1-week apart after an overnight fast, standard breakfast meals including 400 mg docosahexanoic acid (DHA) from either extruded rice snacks or soup both containing cauliflower-encapsulated HiDHA^® algal oil or gel capsules containing HiDHA^® algal oil. Blood samples for analysis of plasma DHA and eicosapentaenoic acid (EPA) were taken pre-meal and after 2, 4, 6, 8 and 24 h. Primary analyses comparing 24-h incremental area under the plasma DHA, EPA and DHA + EPA concentration (µg/ml) curves (iAUC_0-24 h) between test foods were performed using linear mixed models by including ethnicity as an interaction term.

Results

Plasma iAUC_0-24 h did not differ significantly between test foods (adjusted mean [95% CI] plasma DHA + EPA: extruded rice snack, 8391 [5550, 11233] µg/mL*hour; soup, 8862 [6021, 11704] µg/mL*hour; capsules, 11,068 [8226, 13910] µg/mL*hour, P = 0.31) and did not differ significantly between Australian European and Singaporean Chinese (treatment*ethnicity interaction, P = 0.43).

Conclusion

The vegetable-based omega-3 LCPUFA delivery system did not affect bioavailability of omega-3 LCPUFA in healthy young Australian and Singaporean men as assessed after a single meal over 24 h, nor was bioavailability affected by ethnicity. This novel delivery system may be an effective way to fortify foods/beverages with omega-3 LCPUFA.

Trial registration

The trial was registered with clinicaltrials.gov (NCT04610983), date of registration, 22 November 2020.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02795-7.

Pharmacokinetics of Single and Multiple Doses of Omega-3 Carboxylic Acids in Healthy Chinese Subjects: A Phase I, Open-Label Study

In patients with coronary heart disease undergoing primary prevention, hypertriglyceridemia is a residual risk for cardiovascular events. Omega-3 carboxylic acid (OM3-CA), a mixture of the free fatty acid forms of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may be beneficial in reducing triglyceride levels. As part of the clinical development program of OM3-CA in China, this phase I study evaluated the pharmacokinetics, safety, and tolerability profile of OM3-CA in healthy subjects. The pharmacokinetic results of this study were also compared with those of available data for Western populations. Fourteen healthy Chinese subjects (aged 18-45 years) received once-daily oral OM3-CA 4 g for 14 consecutive days. Pharmacokinetic parameters were assessed from both baseline-uncorrected and baseline-corrected plasma concentrations vs time profile of EPA, DHA, and EPA plus DHA. Following single and multiple oral doses of OM3-CA, the absorption of EPA, DHA, and EPA plus DHA was steady with median t_max occurring at 5.5-6 hours after both single and multiple dosing. Close to steady-state concentrations in plasma were reached after 14 days of continuous once-daily dosing, and accumulation was confirmed for EPA, DHA, and EPA plus DHA. Of the 14 subjects treated with OM3-CA, 6 (42.9%) reported at least 1 adverse event (diarrhea) during the study, which was determined as mild and treatment emergent. No serious adverse events were reported. In summary, the pharmacokinetic profile of oral OM3-CA 4 g after single and multiple dosing in healthy Chinese subjects is consistent with that observed in other ethnic populations.

Omega-3 PUFA Responders and Non-Responders and the Prevention of Lipid Dysmetabolism and Related Diseases

The long-chain omega-3 polyunsaturated fatty acids (LC-omega-3 PUFAs) eicosapentaenoic acid and docosahexaenoic acid are the most popular dietary supplements recommended for the prevention/management of lipid dysmetabolisms and related diseases. However, remarkable inconsistencies exist among the outcomes of the human intervention studies in this field, which contrast with the impressive homogeneity of positive results of most of the preclinical studies. In the present review, we will firstly examine a series of factors-such as background diet composition, gut microbiota and genetic/epigenetic variants, which may lie beneath these inconsistencies. Moreover, we will discuss the recent advance in the knowledge of possible specific biomarkers (genetic-, epigenetic- and microbiota-related) that are being investigated with the goal to apply them in a personalized supplementation with omega-3 PUFAs. We will also consider the possibility of using already available parameters (Omega-3 index, Omega-6 PUFA/Omega-3 PUFA ratio) able to predict the individual responsiveness to these fatty acids and will discuss the optimal timing for their use. Finally, we will critically examine the results of those human studies that have already adopted the distinction of the subjects into omega-3 PUFA responders and non-responders and will discuss the advantage of using such an approach.

Evaluation of OM3-PL/FFA Pharmacokinetics After Single and Multiple Oral Doses in Healthy Volunteers

PURPOSE

The US Food and Drug Administration has approved several omega-3 (OM3)-containing prescription drugs for the treatment of severe hypertriglyceridemia (HTG). However, there is still a need to develop formulations with high bioavailability irrespective of the fat content and time of the meal. OM3-phospholipid (PL)/free fatty acid (FFA) is an investigational drug for the treatment of severe HTG containing naturally derived krill oil mixture of OM3, mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as PL esters and as FFA. Both forms in OM3-PL/FFA are believed to be readily bioavailable. Per gram, OM3-PL/FFA contains a lower dose of EPA/DHA in comparison with already approved prescription drugs. The study aim was to evaluate OM3-PL/FFA pharmacokinetic (PK) properties after single and multiple oral doses of 1, 2, and 4 g in healthy subjects when receiving a Therapeutic Lifestyle Change (TLC) diet. The dose proportionality of the study drug, the effect of a high-fat (HF) meal on its PK properties and its safety profile after multiple administration were also explored.

METHODS

In this Phase I, open-label, randomized, multiple-dose, single-center, parallel-design study, 42 healthy volunteers following a TLC diet were randomly assigned into 1 of 3 treatment groups in a 1:1:1 ratio to receive a single dose at day 1, followed by multiple oral doses of 1, 2, and 4 g/d for 14 days. At day 15, all subjects received a HF breakfast.

FINDINGS

After once-daily dosing, based on graphic assessment, OM3-PL/FFA levels reached steady state within 7-10 days. Exposure of total EPA + DHA, total DHA, and total EPA (C_max and AUC) appeared to be approximately proportional over the 1-4 g/d dose range. After 14 days of repeated daily dosing, accumulation was observed and was greater at the higher dose of the study product. When administered after a HF breakfast on day 15, median t_max, the geometric mean of AUC_0-24 and C_max were comparable with the values on day 14 across the 3 dose levels.

IMPLICATIONS

OM3-PL/FFA was found to be well tolerated in healthy subjects. The study drug PK properties appeared to be approximately dose proportional over the 1-4 g/d dose range. The bioavailability of OM3-PL/FFA did not appear to be meaningfully affected by the fat content of the meal consumed before dose administration. This is clinically relevant because a low-fat diet is part of the management of patients with HTG.

Effect of omega-3 fatty acid plus vitamin E Co-Supplementation on lipid profile: A systematic review and meta-analysis

BACKGROUND

Dyslipidemia is linked to chronic inflammation, which in return leads to a set of chronic disorders. Omega-3 fatty acids have been reported to reduce inflammation. Furthermore, Vitamin E is a fat-soluble vitamin which has antioxidant and anti-inflammatory effects. Vitamin E and omega-3 fatty acids co-supplementations may be more effective than the single supplementation in control dyslipidemia. Therefore, we designed and conducted the current systematic review and meta-analysis to investigate the effect of co-supplementation of vitamin E and omega-3 fatty acids on the lipid profile.

METHODS

A comprehensive search for studies published between January 1990 and July 2018 was performed. The initial search extracted 3015 potentially relevant articles. After studying these publications, 9 RCTs were potentially eligible and retrieved in full text.

RESULTS

The meta-analysis indicate that on total cholesterol, HDL, LDL and triglyceride individually did not show any significant difference between intervention and control groups, but vitamin E an omega-3 fatty acids co-supplementations significantly reduce VLDL levels.

CONCLUSIONS

Based on the available evidence, omega-3 fatty acid and vitamin E co-supplementation can reduce VLDL, although its effect on other lipid profile parameters requires more well-designed studies.

Omega-3 carboxylic acids in patients with severe hypertriglyceridemia: EVOLVE II, a randomized, placebo-controlled trial

BACKGROUND

Adult patients with severe hypertriglyceridemia (SHTG) are at increased risk of developing acute pancreatitis and cardiovascular disease. Omega-3 carboxylic acids (OM3-CA) are approved for treatment as an adjunct to diet to reduce triglyceride (TG) concentrations in patients with SHTG.

OBJECTIVE

The aim of the study was to assess efficacy and safety of the intermediate dose of OM3-CA (2 g daily), compared with olive oil 2 g daily, in reducing serum TG and lipid concentrations in patients with SHTG.

METHODS

A randomized, double-blind, olive oil-controlled, parallel-group trial involving 162 adults with qualifying serum TG concentrations of at least 500 mg/dL (5.65 mmol/L) and <2500 mg/dL (28.25 mmol/L; <2000 mg/dL [22.60 mmol/L] in Canada). The treatment period after randomization was 12 weeks. Blood samples for measurement of fasting serum lipid concentrations were taken at baseline, 6, 10, and 12 weeks.

RESULTS

Treatment with OM3-CA 2 g daily led to a significant reduction in TG concentrations (median of differences, -14.2% [95% confidence interval: -26.2%, -2.8%; P = .017]) and non-high-density lipoprotein cholesterol concentrations (median of differences, -9.0% [95% confidence interval: -14.8%, -2.8%; adjusted P = .018]) from baseline to the Week 12 endpoint, when compared with olive oil 2 g daily. These treatment effects were more pronounced in patients with qualifying TG concentrations >885 mg/dL (10 mmol/L).

CONCLUSION

An intermediate dose of OM3-CA (2 g daily) significantly lowers TG and non-high-density lipoprotein cholesterol concentrations in patients with SHTG and may benefit individuals at risk of acute pancreatitis and cardiovascular disease.

Selection in Europeans on Fatty Acid Desaturases Associated with Dietary Changes

FADS genes encode fatty acid desaturases that are important for the conversion of short chain polyunsaturated fatty acids (PUFAs) to long chain fatty acids. Prior studies indicate that the FADS genes have been subjected to strong positive selection in Africa, South Asia, Greenland, and Europe. By comparing FADS sequencing data from present-day and Bronze Age (5-3k years ago) Europeans, we identify possible targets of selection in the European population, which suggest that selection has targeted different alleles in the FADS genes in Europe than it has in South Asia or Greenland. The alleles showing the strongest changes in allele frequency since the Bronze Age show associations with expression changes and multiple lipid-related phenotypes. Furthermore, the selected alleles are associated with a decrease in linoleic acid and an increase in arachidonic and eicosapentaenoic acids among Europeans; this is an opposite effect of that observed for selected alleles in Inuit from Greenland. We show that multiple SNPs in the region affect expression levels and PUFA synthesis. Additionally, we find evidence for a gene-environment interaction influencing low-density lipoprotein (LDL) levels between alleles affecting PUFA synthesis and PUFA dietary intake: carriers of the derived allele display lower LDL cholesterol levels with a higher intake of PUFAs. We hypothesize that the selective patterns observed in Europeans were driven by a change in dietary composition of fatty acids following the transition to agriculture, resulting in a lower intake of arachidonic acid and eicosapentaenoic acid, but a higher intake of linoleic acid and α-linolenic acid.

Alternative sources of n-3 long-chain polyunsaturated fatty acids in marine microalgae

The main source of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in human nutrition is currently seafood, especially oily fish. Nonetheless, due to cultural or individual preferences, convenience, geographic location, or awareness of risks associated to fatty fish consumption, the intake of fatty fish is far from supplying the recommended dietary levels. The end result observed in most western countries is not only a low supply of n-3 LC-PUFA, but also an unbalance towards the intake of n-6 fatty acids, resulting mostly from the consumption of vegetable oils. Awareness of the benefits of LC-PUFA in human health has led to the use of fish oils as food supplements. However, there is a need to explore alternatives sources of LC-PUFA, especially those of microbial origin. Microalgae species with potential to accumulate lipids in high amounts and to present elevated levels of n-3 LC-PUFA are known in marine phytoplankton. This review focuses on sources of n-3 LC-PUFA, namely eicosapentaenoic and docosahexaenoic acids, in marine microalgae, as alternatives to fish oils. Based on current literature, examples of marketed products and potentially new species for commercial exploitation are presented.

The relationship between dietary fatty acids and inflammatory genes on the obese phenotype and serum lipids

Obesity, a chronic low-grade inflammatory condition is associated with the development of many comorbidities including dyslipidemia. This review examines interactions between single nucleotide polymorphisms (SNP) in the inflammatory genes tumor necrosis alpha (TNFA) and interleukin-6 (IL-6) and dietary fatty acids, and their relationship with obesity and serum lipid levels. In summary, dietary fatty acids, in particular saturated fatty acids and the omega-3 and omega-6 polyunsaturated fatty acids, impact the expression of the cytokine genes TNFA and IL-6, and alter TNFα and IL-6 production. In addition, sequence variants in these genes have also been shown to alter their gene expression and plasma levels, and are associated with obesity, measures of adiposity and serum lipid concentrations. When interactions between dietary fatty acids and TNFA and IL-6 SNPs on obesity and serum lipid were analyzed, both the quantity and quality of dietary fatty acids modulated the relationship between TNFA and IL-6 SNPs on obesity and serum lipid profiles, thereby impacting the association between phenotype and genotype. Researching these diet–gene interactions more extensively, and understanding the role of ethnicity as a confounder in these relationships, may contribute to a better understanding of the inter-individual variability in the obese phenotype.

Improved utilization of fish waste by anaerobic digestion following omega-3 fatty acids extraction

Fish waste is a potentially valuable resource from which high-value products can be obtained. Anaerobic digestion of the original fish waste and the fish sludge remaining after enzymatic pre-treatment to extract fish oil and fish protein hydrolysate was evaluated regarding the potential for methane production. The results showed high biodegradability of both fish sludge and fish waste, giving specific methane yields of 742 and 828 m(3)CH(4)/tons VS added, respectively. However, chemical analysis showed high concentrations of light metals which, together with high fat and protein contents, could be inhibitory to methanogenic bacteria. The feasibility of co-digesting the fish sludge with a carbohydrate-rich residue from crop production was thus investigated, and a full-scale process outlined for converting odorous fish waste to useful products.

Diabetes Health, Residence & Metabolism in Asians: the DHRMA study, research into foods from the Indian subcontinent - a blinded, randomised, placebo controlled trial

Background

Coronary heart disease (CHD) is highly prevalent amongst the South Asian communities in Britain. The reasons for this excess CHD risk are multifactorial, but in part relate to a susceptibility to diabetes mellitus - where the aberrant metabolism of non-esterified fatty acids (NEFA) and glucose are likely to underpin vascular disease in this population. Dietary intervention is an important and first line approach to manage increased CHD risk. However, there is limited information on the impact of the South Asian diet on CHD risk.

Methods/Design

The Diabetes Health, Residence & Metabolism in Asians (DHRMA) study is a blinded, randomised, placebo controlled trial that analyses the efficacy of reduced glycaemic index (GI) staples of the South Asian diet, in relation to cardio-metabolic risk factors that are commonly perturbed amongst South Asian populations - primarily glucose, fatty acid and lipoprotein metabolism and central adiposity. Using a 10-week dietary intervention study, 50 healthy South Asians will be randomised to receive either a DHRMA (reduced GI) supply of chapatti (bread), stone ground, high protein wheat flour and white basmati rice (high bran, unpolished) or commercially available (leading brand) versions chapatti wheat flour and basmati rice. Volunteers will be asked to complete a 75g oral glucose tolerance test at baseline and at 10-weeks follow-up, where blood metabolites and hormones, blood pressure and anthropometry will also be assessed in a standardised manner.

Discussion

It is anticipated that the information collected from this study help develop healthy diet options specific (but not exclusive) for South Asian ethnic communities.

Trial registration

Current Controlled Trials ISRCTN02839188

Health benefits of marine foods and ingredients

The health benefits of seafood consumption have primarily been associated with protective effects against cardiovascular diseases (CVD). However, intake of seafood has also been associated with improved foetal and infant development, as well as several other diseases and medical conditions. The health promoting effects have chiefly been attributed to the long-chain n-3 polyunsaturated fatty acids (n-3 PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In addition, the general fatty acid profile is considered favourable. On the other hand, recent and emerging research on seafood proteins and other seafood derived components suggest that these nutritional components contribute to the health effects. In this paper we review the nutritional characteristics and health benefits of marine foods and ingredients, and discuss some current and future trends in marine food production.

Reduced thrombin formation and altered fibrin clot properties induced by polyunsaturated omega-3 fatty acids on top of dual antiplatelet therapy in patients undergoing percutaneous coronary intervention (OMEGA-PCI clot)

OBJECTIVE

The goal of this study was to investigate whether omega-3 polyunsaturated fatty acids (n-3 PUFA) are able to alter plasma fibrin clot properties and reduce thrombin formation in stable coronary artery disease patients undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

In an investigator-initiated, prospective, double-blind, placebo-controlled, randomized study, patients undergoing PCI who received standard pharmacotherapy were assigned to the treatment with 1 g/day n-3 PUFA (n = 30) or placebo (n = 24) for 1 month. Plasma fibrin clot permeability (K(s)); lysis time (t(50%)); prothrombin fragment 1.2; and peak thrombin generation from automated thrombogram, 8-isoprostaglandin F(2α) (8-iso-PGF(2α), an oxidative stress marker), and C-reactive protein were determined at baseline, 3 to 5 days after randomization, and 30 days after randomization. At baseline, both treatment groups did not differ significantly. A 1-month treatment with n-3 PUFA compared with placebo was associated with 15.3% higher K(s), indicating larger pores in the fibrin network (P = 0.0005); 14.3% shorter t(50%), indicating increased susceptibility to fibrinolysis (P<0.0001); 33.8% lower prothrombin fragment 1.2 (P = 0.0013); 13.4% lower peak thrombin generation (P = 0.04); and 13.1% lower 8-iso-PGF(2α) (P = 0.009). Treatment with n-3 PUFA had no effect on fibrinogen and C-reactive protein. After 1 month of treatment, fibrinogen (r = -0.53, P<0.0001), treatment assignment (r = 0.29, P = 0.006) and 8-iso-PGF(2α) (r = -0.27, P = 0.015) were independently associated with clot permeability (P<0.0001, R(2) = 0.66).

CONCLUSIONS

Adding n-3 PUFA to standard therapy in stable patients undergoing PCI significantly decreases thrombin formation and oxidative stress and favorably alters fibrin clot properties. These findings indicate novel antithrombotic effects induced by n-3 PUFA in humans.