The differential effects of EPA and DHA on cardiovascular risk factors

Algae-derived compounds: Bioactivity, allergenicity and technologies enhancing their values

As a rapidly growing source of human nutrients, algae biosynthesize diverse metabolites which have promising bioactivities. However, the potential allergenicity of algal components hinder their widespread adoption. This review provides a comprehensive review of various macro and micronutrients derived from algal biomass, with particular focus on bioactive compounds, including peptides, polyphenols, carotenoids, omega-3 fatty acids and phycocyanins. The approaches used to produce algal bioactive compounds and their health benefits (antioxidant, antidiabetic, cardioprotective, anti-inflammatory and immunomodulatory) are summarised. This review particularly focuses on the state-of-the-art of precision fermentation, encapsulation, cold plasma, high-pressure processing, pulsed electric field, and subcritical water to reduce the allergenicity of algal compounds while increasing their bioactivity and bioavailability. By providing insights into current challenges of algae-derived compounds and opportunities for advancement, this review contributes to the ongoing discourse on maximizing their application potential in the food nutraceuticals, and pharmaceuticals industries.

Diet and Nutraceuticals for treatment and prevention of primary and secondary stroke: Emphasis on nutritional antiplatelet and antithrombotic agents

Ischemic stroke is a devastating disease that causes morbidity and mortality. Malnutrition following ischemic stroke is common in stroke patients. During the rehabilitation, the death rates of stroke patients are significantly increased due to malnutrition. Nutritional supplements such as protein, vitamins, fish, fish oils, moderate wine or alcohol consumption, nuts, minerals, herbal products, food colorants, marine products, fiber, probiotics and Mediterranean diets have improved neurological functions in stroke patients as well as their quality of life. Platelets and their mediators contribute to the development of clots leading to stroke. Ischemic stroke patients are treated with thrombolytics, antiplatelets, and antithrombotic agents. Several systematic reviews, meta-analyses, and clinical trials recommended that consumption of these nutrients and diets mitigated the vascular, peripheral, and central complications associated with ischemic stroke (Fig. 2). Particularly, these nutraceuticals mitigated the platelet adhesion, activation, and aggregation that intended to reduce the risks of primary and secondary stroke. Although these nutraceuticals mitigate platelet dysfunction, there is a greater risk of bleeding if consumed excessively. Moreover, malnutrition must be evaluated and adequate amounts of nutrients must be provided to stroke patients during intensive care units and rehabilitation periods. In this review, we have summarized the importance of diet and nutraceuticals in ameliorating neurological complications and platelet dysfunction with an emphasis on primary and secondary prevention of ischemic stroke.

Chemical Composition and Lipid Bioactive Components of Centaurea thracica Dwelling in Bulgaria

Centaurea thracica (Janka) Hayek is a plant common in southern Bulgaria. The inflorescences were collected during June and September 2021, while their seeds were obtained in September 2021. The chemical and lipid composition of the inflorescences during the vegetation process of the plant were established. A significant decrease in total proteins (from 8.7 to 7.4%), glyceride oils (2.0-1.7%), and ash (4.5-4.2%) content was observed, while the amount of carbohydrates (72.3-77.2%) and fibers (28.7-35.8%) increased. During the vegetation of the plant, the content of oleic and linoleic acids increased up to 2-3 times, while the level of palmitic acid decreased. The lipids from the seeds were rich in oleic (53.0%) and palmitic (36.2%) acids. The tocopherol content in the oils of the inflorescences during vegetation increased from 58 to 110 mg/kg, and the content in the oil from the seeds was 260 mg/kg. The phospholipid content decreased during vegetation, and differences were observed in the composition between the inflorescences and the seeds. The high content of oleic acid, linoleic acid, tocopherols, and phospholipids determine the nutritional and biological value of the oils isolated from Centaurea thracica, and contribute to their potential use in various directions.

Spatial and ontogenetic modulation of fatty acid composition in juvenile European sea bass (Dicentrarchus labrax) from two French estuaries

This study evaluated how estuary of origin and ontogenetic stage influence the fatty acid (FA) composition in the tissues of wild European sea bass juvenile. We evidenced tissue-specific patterns, with the brain exhibiting a distinct FA composition from the liver and muscle. Ontogenetic stage and estuary influenced the general FA profile, and particularly the essential FA (EFA) like docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (ARA) in all tissues. The data also revealed the ability of wild sea bass to modulate, at the molecular level, FA biosynthesis pathways and suggest a potential dietary DHA limitation in the natural environment. The distribution of FA within tissues might reflect shifts in diet, metabolic demands, or adaptations to environmental conditions. This study provides insights about FA dynamics in euryhaline fish during juvenile life stage, improving our understanding of the metabolism need and EFA trophic availability in a changing environment.

The effect of curcumin and high-content eicosapentaenoic acid supplementations in type 2 diabetes mellitus patients: a double-blinded randomized clinical trial

BACKGROUND/OBJECTIVES

The present study investigated the effect of curcumin and eicosapentaenoic acid, as one the main components of omega-3 polyunsaturated fatty acids, on anthropometric, glucose homeostasis, and gene expression markers of cardio-metabolic risk in patients with type 2 diabetes mellitus.

SUBJECTS/METHODS

This clinical trial was conducted at the Endocrinology Clinic of Imam Reza Hospital in Tabriz. It aimed to determine the impact of Eicosapentaenoic Acid (EPA), Docosahexaenoic Acid (DHA), and curcumin supplements on various health indicators in patients with Type 2 Diabetes Mellitus (DM2) from 2021.02.01 to 2022.02.01. The study was a randomized double-blinded clinical trial and conducted over 12 weeks with 100 participants randomly divided into four groups. Stratified randomization was used to assign participants to two months of supplementation based on sex and Body Mass Index (BMI). The study comprised four groups: Group 1 received 2 capsules of 500 mg EPA and 200 mg DHA, along with 1 nano-curcumin placebo; Group 2 received 1 capsule of 80 mg nano-curcumin and 2 omega 3 Fatty Acids placebos; Group 3 received 2 capsules of 500 mg EPA and 200 mg DHA, and 1 capsule of 80 mg nano-curcumin; Group 4, the control, received 2 omega 3 Fatty Acids placebos and 1 nano-curcumin placebo.

RESULTS

After twelve weeks of taking EPA + Nano-curcumin supplements, the patients experienced a statistically significant reduction in insulin levels in their blood [MD: -1.44 (-2.70, -0.17)]. This decrease was significantly greater than the changes observed in the placebo group [MD: -0.63 (-1.97, 0.69)]. The EPA + Nano-curcumin group also showed a significant decrease in High-Sensitivity C-Reactive Protein (hs-CRP) levels compared to the placebo group (p < 0.05). Additionally, the EPA + Nano-curcumin group had a significant increase in Total Antioxidant Capacity (TAC) levels compared to the placebo group (p < 0.01). However, there were no significant differences in Fasting Blood Sugar (FBS), Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) index, Quantitative Insulin Sensitivity Check Index (QUICKI), or Hemoglobin A1c (HbA1C) levels between the four groups (all p > 0.05). There were significant differences between the Nano-curcumin and EPA groups [MD: -17.02 (-32.99, -1.05)], and between the Nano-curcumin and control groups [MD: -20.76 (-36.73, -4.79)] in terms of lowering the serum cholesterol level. The difference in Triglycerides (TG) serum levels between the EPA + Nano-curcumin and placebo groups were not statistically significant (p = 0.093). The Nano-curcumin group showed significant decreases in Low-Density Lipoprotein (LDL) levels compared to the EPA group [MD: -20.12 (-36.90, -3.34)] and the control group [MD: -20.79 (-37.57, -4.01)]. There was a near-to-significant difference in High-Density Lipoprotein (HDL) serum levels between the EPA + Nano-curcumin and EPA groups (p = 0.056). Finally, there were significant differences in the decrease of serum Vascular Endothelial Growth Factor (VEGF) levels between the EPA and Nano-curcumin groups [MD: -127.50 (-247.91, -7.09)], the EPA and placebo groups [MD: 126.25 (5.83, 246.66)], the EPA + Nano-curcumin and Nano-curcumin groups [MD: -122.76 (-243.17, -2.35)], and the EPA + Nano- curcumin and placebo groups [MD: 121.50 (1.09, 241.92)].

CONCLUSIONS

The findings of the present study suggest that 12-week supplementation with EPA and Nano-curcumin may positively impact inflammation, oxidative stress, and metabolic parameters in patients with diabetes. The supplementation of EPA and Nano-curcumin may be a potential intervention to manage diabetes and reduce the risk of complications associated with diabetes. However, further research is needed to validate the study's findings and establish the long-term effects of EPA and Nano-curcumin supplementation in patients with diabetes.

Discovery of small molecules from natural compound databases as potent retinoid X alpha receptor agonists to treat Alzheimer's disease

Alzheimer's is characterized as a progressive neurodegenerative disease due to beta-amyloid accumulation in the brain. Some previous studies reported that RXR agonists could be effective in the treatment of Alzheimer's disease. There are currently numerous attempts being made to discover a natural RXR agonist that is more potent than 9-cis-retinoic acid (9CR). One of the most efficient resources for finding high-potential compounds is natural databases. In this study, 81215 compounds from the IB screen library as natural databases were docked against the RXR-alpha binding site. The best compounds discovered interact with the RXR-alpha binding site with a lower binding energy (-11 to -13 kcal/mol) than the binding energy of -10.94 kcal/mol for 9-cis, which means that these compounds could interact stronger with RXR-alpha than 9CR. All selected compounds could pass the blood-brain barrier. Physiochemical properties assessment indicated that all compounds passed Lipinski's rule and had the potential to be oral drug candidates. The stability of protein-ligand complexes during a timescale of 100 ns by Molecular Dynamics simulation demonstrated that all compounds could effectively interact with the RXR binding site. The molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) represented that all selected hit compounds had a better binding affinity to the alpha RXR binding site compared to 9CR, which means these hit compounds had potential drug candidates for the treatment of Alzheimer's disease. However, experimental assessment is needed to validate this result.Communicated by Ramaswamy H. Sarma.

Omega-3 eicosapentaenoic polar-lipid rich extract from microalgae Nannochloropsis decreases plasma triglycerides and cholesterol in a real-world normolipidemic supplement consumer population

Introduction

AlmegaPL® is an oil rich in polar-lipid (> 15% w/w) derived from the microalga Nannochloropsis, that contains exclusively eicosapentaenoic acid (EPA > 25% w/w), without the DHA that is present in all other natural sources of omega-3. Previous findings from a randomized controlled clinical trial demonstrated the ability of AlmegaPL® supplementation to reduce cholesterol levels.

Methods

In this post-market cohort study, we built upon previous findings and targeted the actual end-users of the supplement. Participants were recruited from a new subscriber database of AlmegaPL® capsules (1000-1100 mg/day) to capture the complexity of real-world clinical and consumer settings. Changes in circulating triglycerides (TG), remnant cholesterol (RC), low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), total cholesterol (TC), high-sensitivity C-reactive protein (hs-CRP), glucose and glycated hemoglobin (HbA1c) were monitored at baseline, Month 3, and Month 6 of supplementation using the at-home Baseline Heart Health Testing Kit by Imaware® (Houston, TX, USA).

Results

Participants, who had, on average, normal TG level at baseline (1.62 ± 0.60 mmol/L), experienced a significant and progressive decrease in TG at Month 3 (8.0%; -0.13 ± 0.59 mmol/L; p < 0.001) and Month 6 (14.2%; -0.23 ± 0.64 mmol/L; p < 0.001) (primary outcome). Furthermore, after 6 months of supplementation, TC and non-HDL-cholesterol decreased by 5.0% (-0.26 ± 0.98 mmol/L; p < 0.001) and 5.5% (-0.21 ± 0.86 mmol/L; p < 0.001) respectively, primarily driven by a 14.9% reduction in RC (-0.11 ± 0.29 mmol/L; p < 0.001).

Discussion

Consistent with our previous clinical trial, the decrease in RC was not coupled to an increase in LDL, which seems to be a benefit associated with EPA-only based formulations. In addition, this study demonstrated the AlmegaPL® capacity to maintain already healthy TG levels by further inducing a 14.9% decrease. Collectively, these findings highlight AlmegaPL® uniqueness as a natural over-the-counter option for EPA-only polar lipid that appears particularly effective in maintaining blood lipid levels in a generally healthy, normolipidemic population.

Clinical trial registration

https://clinicaltrials.gov/, identifier NCT05267301.

Decreased in n-3 DHA enriched triacylglycerol in small extracellular vesicles of diabetic patients with cardiac dysfunction

PURPOSE

Diabetic cardiomyopathy is the leading cause of death in diabetic patients, and the mechanism by which factors other than hyperglycemia contribute to the development of diabetic cardiomyopathy is unknown. Serum small extracellular vesicles (sEVs) carry bioactive proteins or nuclei, which enter into remote tissues and modulate cell functions. However, in diabetic conditions, the changes of lipids carried by sEVs has not been identified. Our study aims to explore the changes of lipids in sEVs in diabetic patients with cardiovascular disease, we hope to provide new ideas for understanding the role of lipid metabolism in the pathogenesis of diabetic cardiomyopathy.

METHODS

SEVs samples derived from serum of health controls (Ctrl), diabetic patients without cardiovascular diseases (DM), and diabetic patients with cardiovascular diseases (DM-CAD) were used for lipidomics analysis. Because AC16 cells are also treated with those sEVs to confirm the entrance of cells and effects on insulin sensitivity, a lipidomics analysis on cells was also performed.

RESULTS AND CONCLUSIONS

In this study, we found that docosahexaenoic acid (DHA)-triacylglycerides of sEVs from serums of DM-CAD patients decreased significantly, and those sEVs could enter into AC16 cells and diminish insulin sensitivity. In addition, DHA-triacylglycerides were also decreased in cells treated with sEVs from DM-CAD. Therefore, DHA-triacylglycerides carried by sEVs may mediate intercellular signaling and be associated with the incidence of diabetic cardiovascular complications.

Cardiovascular Diseases and Marine Oils: A Focus on Omega-3 Polyunsaturated Fatty Acids and Polar Lipids

Cardiovascular diseases (CVD) remain the leading cause of death across the globe, hence, establishing strategies to counteract CVD are imperative to reduce mortality and the burden on health systems. Dietary modification is an effective primary prevention strategy against CVD. Research regarding dietary supplementation has become increasingly popular. This review focuses on the current in vivo, in vitro, and epidemiological studies associated with that of omega-3 polyunsaturated fatty acids (n-3 PUFAs) and polar lipids (PLs) and how they play a role against CVD. Furthermore, this review focuses on the results of several major clinical trials examining n-3 PUFAs regarding both primary and secondary prevention of CVD. Notably, we place a lens on the REDUCE-IT and STRENGTH trials. Finally, supplementation of PLs has recently been suggested as a potential alternative avenue for the reduction of CVD incidence versus neutral forms of n-3 PUFAs. However, the clinical evidence for this argument is currently rather limited. Therefore, we draw on the current literature to suggest future clinical trials for PL supplementation. We conclude that despite conflicting evidence, future human trials must be completed to confirm whether PL supplementation may be more effective than n-3 PUFA supplementation to reduce cardiovascular risk.

Associations of circulating fatty acids with incident coronary heart disease: a prospective study of 89,242 individuals in UK Biobank

BACKGROUND

The role of fatty acids in coronary heart disease (CHD) remains uncertain. There is little evidence from large-scale epidemiological studies on the relevance of circulating fatty acids levels to CHD risk. This study aims to examine the independent associations of the major circulating types of fatty acids with CHD risk.

METHODS

UK Biobank is a prospective study of adults aged 40-69 in 2006-2010; in 2012-2013, a subset of the participants were resurveyed. Analyses were restricted to 89,242 participants with baseline plasma fatty acids (measured using nuclear magnetic resonance spectroscopy) and without prior CHD. Cox proportional hazards models were used to estimate hazard ratios (HRs) for the associations with incidence CHD, defined as the first-ever myocardial infarction, unstable angina pectoris, coronary-related death, or relevant procedure. And the major types of fatty acids were mutually adjusted to examine the independent associations. Hazard ratios were corrected for regression dilution using the correlation of baseline and resurvey fatty acids measures.

RESULTS

During a median follow-up of 11.8 years, 3,815 incident cases of CHD occurred. Independently of other fatty acids, CHD risk was positively associated with saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA), inversely associated with omega-3 polyunsaturated fatty acids (PUFA), but there was no strong evidence of an association with omega-6 PUFA: HR per standard deviation higher were 1.14 (95% CI, 1.09-1.20), 1.15 (1.10-1.21), 0.91 (0.87-0.94), and 1.04 (0.99-1.09) respectively. Independently of triglycerides and cholesterol, the inverse association with omega-3 PUFA was not materially changed, but the positive associations with SFA and MUFA attenuated to null after adjusting for triglycerides levels.

CONCLUSIONS

This large-scale study has quantitated the independent associations of circulating fatty acids with CHD risk. Omega-3 PUFA was inversely related to CHD risk, independently of other fatty acids and major lipid fractions. By contrast, independently of other fatty acids, the positive associations of circulating SFA and MUFA with CHD risk were mostly attributed to their relationship with triglycerides.

Blood lipid profiles, fatty acid deposition and expression of hepatic lipid and lipoprotein metabolism genes in laying hens fed palm oils, palm kernel oil, and soybean oil

The palm oil, palm kernel oil and soybean oil have unique and distinctive fatty acid chain length and saturation profiles, and how they affect lipid peroxidation, fatty acid intake and metabolism is worth exploring in poultry. This study elucidated the influence the dietary oils on lipid peroxidation, blood lipid profiles, fatty acid deposition of liver, serum and yolk and the expression of liver genes related to lipid and lipoprotein metabolism in laying hens. About 150 Hisex brown laying hens were fed diets containing crude palm oil (CPO), red palm oil (RPO), refined palm oil (RBD), palm kernel oil (PKO) or soybean oil (SBO) for 16 weeks. Serum, liver and yolk lipid peroxidation were not different between dietary oils. The PKO increased liver, serum and yolk medium-chain fatty acids (MCFA). There was no difference in liver saturated fatty acids (SFA). The CPO and RPO reduced serum SFA, but the PKO increased yolk SFA. The SBO increased polyunsaturated fatty acids (PUFA) in liver serum and yolk. No difference in liver elaidic acid (C18:1-trans), but SBO lowered elaidic acid (C18:1-trans) in serum. Higher very-low density lipoprotein (VLDL) in CPO than RPO and SBO and greater serum lipase in CPO, RBD and PKO than SBO. There was no difference in sterol regulatory element-binding protein 2 (SREBP-II) between oils. Apolipoprotein VLDL-II (APOVLDL2) was upregulated in palm oils and apolipoprotein B-100 (APOB) in RBD. Downregulation in peroxisome proliferator-activated receptor-alpha (PPAR-α), peroxisome proliferator-activated receptor gamma (PPAR-γ) and low-density lipoprotein receptor (LDLR) was observed in palm oils and PKO. In conclusion, different dietary oils greatly influence several aspects of fatty acid metabolism, deposition and lipoprotein profiles but have no influence on reducing lipid peroxidation.

Durvillaea antarctica: A Seaweed for Enhancing Immune and Cardiometabolic Health and Gut Microbiota Composition Modulation

Durvillaea antarctica is the seaweed that is the most consumed by the Chilean population. It is recognized worldwide for its high nutritional value in protein, vitamins, minerals, and dietary fiber. This is a narrative review in which an extensive search of the literature was performed to establish the immunomodulator, cardiometabolic, and gut microbiota composition modulation effect of Durvillaea antarctica. Several studies have shown the potential of Durvillaea antarctica to function as prebiotics and to positively modulate the gut microbiota, which is related to anti-obesity, anti-inflammatory, anticancer, lipid-lowering, and hypoglycemic effects. The quantity of Bacteroides was negatively correlated with that of inflammatory monocytes and positively correlated with the levels of several gut metabolites. Seaweed-derived polysaccharides modulate the quantity and diversity of beneficial intestinal microbiota, decreasing phenol and p-cresol, which are related to intestinal diseases and the loss of intestinal function. Additionally, a beneficial metabolic effect related to this seaweed was observed, mainly promoting the decrease in the glycemic levels, lower cholesterol levels and cardiovascular risk. Consuming Durvillaea antarctica has a positive impact on the immune system, and its bioactive compounds provide beneficial effects on glycemic control and other metabolic parameters.

Omega-3 and Omega-6 Polyunsaturated Fatty Acid Intakes, Determinants and Dietary Sources in the Spanish Population: Findings from the ANIBES Study

The multiple roles of polyunsaturated fatty acids (PUFA) in growth and general health are well documented. However, available intake data for the Spanish population are limited and lack gender and age considerations. Therefore, our goal was to assess dietary intake adequacy of omega-3 and omega-6 PUFA, their determinants and their major food sources among the Spanish population. Due to their influence on various beneficial functions attributed to omega-3 PUFA, combined intake adequacy with folic acid (FA), vitamin B₁₂ and choline was also assessed. Intake data were obtained from the ANIBES cross-sectional study on a representative sample of the Spanish population (9-75 years; n = 2009), where dietary intake was analysed with a three-day dietary record. Median intake of total omega-3 PUFA stood at 0.81 g/day (0.56-1.19 g/day), with α-linolenic acid (ALA) at 0.61 g/day (0.45-0.85 g/day), eicosapentaenoic acid (EPA) at 0.03 g/day (0.01-0.12 g/day) and docosahexaenoic acid (DHA) at 0.06 g/day (0.0-0.20 g/day). Accordingly, 65% of the Spanish population showed insufficient intakes for total omega-3 PUFA; 87% for ALA, and 83% for combined EPA and DHA. Inadequate intakes were significantly higher in children, adolescents, and younger women of childbearing age (18-30 years). In contrast, inadequacy due to excessive intakes was almost negligible. Regarding omega-6 PUFA, total intake was 10.1 g/day (7.0-14.0 g/day), 10.0 g/day (6.9-13.9 g/day) for linoleic acid (LA) and 0.08 g/day (0.05-0.13 g/day) for arachidonic acid (AA). Non-compliance due to either insufficient or excessive intakes of LA stood at around 5% of the sample, with the elderly showing significantly higher degrees of inadequacy due to insufficient intakes (10%; p ≤ 0.05). Median omega-6 to omega-3 ratio was 12:1, and significantly higher in men compared to women (p ≤ 0.05); in children, adolescents and adults compared to the elderly (p ≤ 0.05); and in younger women of childbearing age compared to the older group (31-45 years) (p ≤ 0.001). Oils and fats and meat and meat products were the main dietary sources for the essential fatty acids LA and ALA, respectively. Meat and meat products were as well the main providers of AA, while fish and shellfish were almost exclusively the only sources of EPA and DHA. However, main food sources identified showed important differences across age groups. Finally, the total combined degree of inadequacy observed for omega-3 PUFA, FA, vitamin B₁₂ and choline reached 21.3% of the ANIBES population. The observed degree of inadequacy of omega-3 PUFA intakes among the Spanish population makes it urgent to increase its consumption and to consider the need for supplementation. This should also be the main strategy for the optimization of the omega-6/omega-3 ratio, as the adequacy observed for omega-6 intakes is relatively acceptable. Additional improvement of the dietary intake of FA, vitamin B₁₂ and choline could contribute to the beneficial effects of omega-3 PUFA.

Comparing the effects of docosahexaenoic and eicosapentaenoic acids on cardiovascular risk factors: Pairwise and network meta-analyses of randomized controlled trials

BACKGROUND

Evidence from clinical trial studies suggests that docosahexaenoic acids (DHA) may have greater potential effects on improving cardiovascular risk factors than eicosapentaenoic acid (EPA). However, this evidence has not yet been meta-analyzed and quantified. The aim of this study was to evaluate and compare the effect of DHA and EPA monotherapy on cardiovascular risk factors based on paired and network meta-analysis.

METHODS

Relevant articles published up to January 2022 were systematically retrieved from relevant databases. We included all Randomized Controlled Trials (RCTs) on adults that directly compared the effects of DHA with EPA and RCTs of indirect comparisons (DHA and EPA monotherapy compared to control groups). Data were pooled by pairwise and network meta-analysis and expressed as mean differences (MDs) with 95% CIs. The study protocol was registered with PROSPERO (Registration ID: CRD42022328630).

RESULTS

Network meta-analysis of comparisons of DHA and EPA suggested significant comparable effects only on LDL-C (MD EPA versus DHA = -8.51 mg/L; 95% CI: -16.67; -0.35). However, the Network meta-analysis not show a significant effect for other risk factors. Furthermore, pairwise meta-analysis of direct comparisons of DHA and EPA showed significant difference in their effects on plasma glucose (MD _{EPA versus DHA} = -0.31 mg/L; 95% CI: -0.60, -0.02), Insulin (MD _{EPA versus DHA} = -2.14 mg/L; 95% CI: -3.26, -1.02), but the results were not significant for risk factors.

CONCLUSION

Our findings suggest that both EPA and DHA act similarly on the markers under study, with slight changes in plasma glucose, insulin, and LDL-C.

Effects of Differences of Breakfast Styles, Such as Japanese and Western Breakfasts, on Eating Habits

A balanced diet and protein source intake are reportedly good for health. However, many people skip breakfast or have a light breakfast. Thus, this study aimed to examine the influence of breakfast styles on eating habits among Japanese workers, including traditional Japanese-style breakfast (JB), a pattern in which Japanese foods are eaten; Japanese-Western-style breakfast (J-W B), a pattern in which Japanese and Western foods are eaten alternately; Western-style breakfast (WB), a pattern in which Western foods are eaten; and cereal-style breakfast (CB), a pattern in which cereal is eaten. We hypothesized that breakfast style may be related to good eating habits. Data from 4274 respondents (67.97% male, 33.03% female, age 48.12 ± 0.19 years), excluding night shift workers and breakfast absentees out of a total of 5535 respondents, were analyzed. The results suggest that Japanese food is linked to the intake of protein sources such as fish, eggs, and soy. Furthermore, it was suggested that Japanese food breakfast is effective for good eating habits, such as not eating irregular amounts of food, not eating snacks, not drinking sweet juices, and having a balanced diet.

Evaluation of growth, primary productivity, nutritional composition, redox state, and antimicrobial activity of red seaweeds Gracilaria debilis and Gracilaria foliifera under pCO2-induced seawater acidification

The genus Gracilaria is an economically important group of seaweeds as several species are utilized for various products such as agar, used in medicines, human diets, and poultry feed. Hence, it is imperative to understand their response to predicted ocean acidification conditions. In the present work, we have evaluated the response of Gracilaria foliifera and Gracilaria debilis to carbon dioxide (pCO₂) induced seawater acidification (pH 7.7) for two weeks in a controlled laboratory conditions. As a response variable, we have measured growth, productivity, redox state, primary and secondary metabolites, and mineral compositions. We found a general increase in the daily growth rate, primary productivity, and tissue chemical composition (such as pigments, soluble and insoluble sugars, amino acids, and fatty acids), but a decrease in the mineral contents under the acidified condition. Under acidification, there was a decrease in malondialdehyde. However, there were no significant changes in the total antioxidant capacity and a majority of enzymatic and non-enzymatic antioxidants, except for an increase in tocopherols, ascorbate and glutathione-s-transferase in G. foliifera. These results indicate that elevated pCO₂ will benefit the growth of the studied species. No sign of oxidative stress markers indicating the acclimatory response of these seaweeds towards lowered pH conditions. Besides, we also found increased antimicrobial activities of acidified samples against several of the tested food pathogens. Based on these observations, we suggest that Gracilaria spp. will be benefitted from the predicted future acidified ocean.

Biotechnological Approaches for Biomass and Lipid Production Using Microalgae Chlorella and Its Future Perspectives

Heavy reliance on fossil fuels has been associated with increased climate disasters. As an alternative, microalgae have been proposed as an effective agent for biomass production. Several advantages of microalgae include faster growth, usage of non-arable land, recovery of nutrients from wastewater, efficient CO₂ capture, and high amount of biomolecules that are valuable for humans. Microalgae Chlorella spp. are a large group of eukaryotic, photosynthetic, unicellular microorganisms with high adaptability to environmental variations. Over the past decades, Chlorella has been used for the large-scale production of biomass. In addition, Chlorella has been actively used in various food industries for improving human health because of its antioxidant, antidiabetic, and immunomodulatory functions. However, the major restrictions in microalgal biofuel technology are the cost-consuming cultivation, processing, and lipid extraction processes. Therefore, various trials have been performed to enhance the biomass productivity and the lipid contents of Chlorella cells. This study provides a comprehensive review of lipid enhancement strategies mainly published in the last five years and aimed at regulating carbon sources, nutrients, stresses, and expression of exogenous genes to improve biomass production and lipid synthesis.

Association between Seafood Intake and Cardiovascular Disease in South Korean Adults: A Community-Based Prospective Cohort Study

Cardiovascular disease (CVD) is the most common non-communicable diseases causing 18.6 million deaths worldwide. Several studies have revealed that seafood consumption has a protective effect against CVD. This study investigated the correlation between CVD and seafood intake based on a 10-year follow-up of the Korean Genome and Epidemiology Study (KoGES). The study population, which included 6565 adults age, 55.65 (±8.68), was divided into seafood intake-based tertiles. CVD included myocardial infarction, coronary artery disease, congestive heart failure, cerebrovascular disease, and peripheral vascular disease. At baseline, participants with low seafood intake also had low eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intakes. Prospectively, hazard ratios (HRs) with 95% confidence intervals (CIs) for CVD were analyzed using Cox proportional hazards regression models. Seafood intake exhibited a significantly inverse relationship with the cumulative CVD incidence over 10 years regardless of sex (women: log-rank test p < 0.001 and men: log-rank test p < 0.0401). The longitudinal association of low seafood intake with the CVD risk was significantly stronger in female participants after adjusting for confounding variables (HR (95% confidence interval (CI)) = 0.718 (0.519−0.993) p-trend = 0.043). These results suggested that seafood consumption potentially ameliorates CVD risk in middle-aged adults.

Trends and Technological Advancements in the Possible Food Applications of Spirulina and Their Health Benefits: A Review

Spirulina is a kind of blue-green algae (BGA) that is multicellular, filamentous, and prokaryotic. It is also known as a cyanobacterium. It is classified within the phylum known as blue-green algae. Despite the fact that it includes a high concentration of nutrients, such as proteins, vitamins, minerals, and fatty acids—in particular, the necessary omega-3 fatty acids and omega-6 fatty acids—the percentage of total fat and cholesterol that can be found in these algae is substantially lower when compared to other food sources. This is the case even if the percentage of total fat that can be found in these algae is also significantly lower. In addition to this, spirulina has a high concentration of bioactive compounds, such as phenols, phycocyanin pigment, and polysaccharides, which all take part in a number of biological activities, such as antioxidant and anti-inflammatory activity. As a result of this, spirulina has found its way into the formulation of a great number of medicinal foods, functional foods, and nutritional supplements. Therefore, this article makes an effort to shed light on spirulina, its nutritional value as a result of its chemical composition, and its applications to some food product formulations, such as dairy products, snacks, cookies, and pasta, that are necessary at an industrial level in the food industry all over the world. In addition, this article supports the idea of incorporating it into the food sector, both from a nutritional and health perspective, as it offers numerous advantages.

North by Southwest: Screening the Naturally Isolated Microalgal Strains from Different Habitats of Iran for Various Pharmaceutical and Biotechnology Applications

Background and Aims

Microalgae are known as a promising source for food, pharmaceutical, and biofuel production while providing environmental advantages. The present study evaluates some newly isolated microalgal strains from north and southwest of Iran as a potential source for high-value products.

Methods

Primitive screening was carried out regarding growth parameters. The molecular and morphological identifications of the selected strains were performed using 18S rRNA gene sequencing. After phylogenic and evolutionary studies, the selected microalgal strains were characterized in terms of protein and pigment content, in addition to the fatty acid profile content. Besides, the CO₂ fixation rate was determined to assess capability for various environmental applications.

Results

All of the selected strains were predominantly belonging to Scenedesmus sp. and Desmodesmus sp. The isolated Scenedesmus sp. VN 009 possessed the highest productivity content and CO₂ fixation rate of 0.054 g·L⁻¹d⁻¹ and 0.1 g·L⁻¹d⁻¹, respectively. Moreover, data from GC/MS analysis demonstrated the high robustness of this strain to produce several valuable fatty acids including α-linolenic acid and linoleic acid in 45% and 20% of total fatty acids.

Conclusions

The identified strains have a great but different potential for SCP, β-carotene, and ω-3 production, as well as CO₂ fixation for environmental purposes. In this study, considering the wide range of microalgal strains in different habitats of Iran, the potential applications of native microalgae for various pharmaceutical, food, and biotechnology purposes were investigated.

Comparison of Fatty Acid Contents and MMP-1 Inhibitory Effects of the Two Antarctic Fish, Notothenia rossii and Champsocephalus gunnari

Total fatty-acid (FA) contents of different organs (stomach, liver, brain, and skin) of two Antarctic fish, marbled rockcod (Notothenia rossii) and mackerel icefish (Champsocephalus gunnari), were examined using gas chromatography–mass spectrometry (GC–MS). N. rossii possessed higher contents of total omega-3, where eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the most represented omega-3 FAs, were distributed throughout all parts of the fish. The highest level of EPA was observed in the skin and that of DHA was observed in the brain of N. rossii. C. gunnari showed organ peculiarity in that most of the omega-3 FAs were found in stomach and skin. Specifically, the highest levels of EPA and DHA were both observed in the stomach. Although N. rossii and C. gunnari both inhabit the Antarctic Southern Oceans, their characteristics in terms of the composition of fatty acids were shown to vary. The extracts were also evaluated for matrix metalloproteinase-1 (MMP-1)-inhibitory activities in UVB-induced human dermal fibroblasts, where extracts of the skin and liver of N. rossii showed the most significant inhibition upon MMP-1 production. These findings provide experimental evidence that the extracts of the Antarctic fish could be utilized as bioactive nutrients, particularly in the enhancement of skin health.

Analysis of Muscle Lipidome in Juvenile Rainbow Trout Fed Rapeseed Oil and Cochayuyo Meal

This study aimed to analyze the effects on the lipidome of juvenile Oncorhynchus mykiss muscle fed 90% Brassica napus “rapeseed” oil and different amounts of Durvillaea antarctica “Cochayuyo” meal (1.5, 3 and 6%) as a replacement for cellulose. The analysis allowed for the identification of 329 lipids, mainly represented by phospholipids and fatty esters. The inclusion of Brassica napus oil significantly increased the levels of C18:2 species and fatty esters of hydroxylated fatty acids, which could play a bioactive role in human health. One of the most abundant lipids in all fillets was Phosphatidylcholine 33:6, which, according to the literature, could be considered a biomarker for the identification of Oncorhynchus mykiss. In all experimental diets, the species Phosphatidylethanolamine 15:1-18:24 showed four-fold higher levels than the control; increments of n-3- and n-6-rich phospholipids were also observed. Diets containing Durvillaea antarctica meal did not generate more significant variation in fish muscle phospholipids relative to the muscle of the rapeseed-oil-only group. These lipid species consist of medium- and long-chain fatty acids with different degrees of unsaturation. Still, it appears that the rapeseed oil masks the lipid contribution of the meal, possibly due to the low levels of total lipids in the macroalgae.

Production, Processing, and Protection of Microalgal n-3 PUFA-Rich Oil

Microalgae have been increasingly considered as a sustainable “biofactory” with huge potentials to fill up the current and future shortages of food and nutrition. They have become an economically and technologically viable solution to produce a great diversity of high-value bioactive compounds, including n-3 polyunsaturated fatty acids (PUFA). The n-3 PUFA, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), possess an array of biological activities and positively affect a number of diseases, including cardiovascular and neurodegenerative disorders. As such, the global market of n-3 PUFA has been increasing at a fast pace in the past two decades. Nowadays, the supply of n-3 PUFA is facing serious challenges as a result of global warming and maximal/over marine fisheries catches. Although increasing rapidly in recent years, aquaculture as an alternative source of n-3 PUFA appears insufficient to meet the fast increase in consumption and market demand. Therefore, the cultivation of microalgae stands out as a potential solution to meet the shortages of the n-3 PUFA market and provides unique fatty acids for the special groups of the population. This review focuses on the biosynthesis pathways and recombinant engineering approaches that can be used to enhance the production of n-3 PUFA, the impact of environmental conditions in heterotrophic cultivation on n-3 PUFA production, and the technologies that have been applied in the food industry to extract and purify oil in microalgae and protect n-3 PUFA from oxidation.

Valorisation of algal biomass to value-added metabolites: emerging trends and opportunities

Algal biomass is a promising feedstock for sustainable production of a range of value-added compounds and products including food, feed, fuel. To further augment the commercial value of algal metabolites, efficient valorization methods and biorefining channels are essential. Algal extracts are ideal sources of biotechnologically viable compounds loaded with anti-microbial, anti-oxidative, anti-inflammatory, anti-cancerous and several therapeutic and restorative properties. Emerging technologies in biomass valorisation tend to reduce the significant cost burden in large scale operations precisely associated with the pre-treatment, downstream processing and waste management processes. In order to enhance the economic feasibility of algal products in the global market, comprehensive extraction of multi-algal product biorefinery is envisaged as an assuring strategy. Algal biorefinery has inspired the technologists with novel prospectives especially in waste recovery, carbon concentration/sequestration and complete utilisation of the value-added products in a sustainable closed-loop methodology. This review critically examines the latest trends in the algal biomass valorisation and the expansive feedstock potentials in a biorefinery perspective. The recent scope dynamics of algal biomass utilisation such as bio-surfactants, oleochemicals, bio-stimulants and carbon mitigation have also been discussed. The existing challenges in algal biomass valorisation, current knowledge gaps and bottlenecks towards commercialisation of algal technologies are discussed. This review is a comprehensive presentation of the road map of algal biomass valorisation techniques towards biorefinery technology. The global market view of the algal products, future research directions and emerging opportunities are reviewed.

RNA-sequencing Reveals a Gene Expression Signature in Skeletal Muscle of a Mouse Model of Age-associated Postoperative Functional Decline

This study aimed to characterize the effects of laparotomy on postoperative physical function and skeletal muscle gene expression in male C57BL/6N mice at 3, 20, and 24 months of age to investigate late-life vulnerability and resiliency to acute surgical stress. Pre and postoperative physical functioning was assessed by forelimb grip strength on postoperative day (POD) 1 and 3 and motor coordination on POD 2 and 4. Laparotomy-induced an age-associated postoperative decline in forelimb grip strength that was the greatest in the oldest mice. While motor coordination declined with increasing age at baseline, it was unaffected by laparotomy. Baseline physical function as stratified by motor coordination performance (low functioning vs high functioning) in 24-month-old mice did not differentially affect postlaparotomy reduction in grip strength. RNA sequencing of soleus muscles showed that laparotomy-induced age-associated differential gene expression and canonical pathway activation with the greatest effects in the youngest mice. Examples of such age-associated, metabolically important pathways that were only activated in the youngest mice after laparotomy included oxidative phosphorylation and NRF2-mediated oxidative stress response. Analysis of lipid mediators in serum and gastrocnemius muscle showed alterations in profiles during aging and confirmed an association between such changes and functional status in gastrocnemius muscle. These findings demonstrate a mouse model of laparotomy which recapitulated some features of postoperative skeletal muscle decline in older adults, and identified age-associated, laparotomy-induced molecular signatures in skeletal muscles. Future research can build upon this model to study molecular mechanisms of late-life vulnerability and resiliency to acute surgical stress.

Relations between the Consumption of Fatty or Lean Fish and Risk of Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis

Fish consumption is associated with a reduced risk of cardiovascular diseases (CVDs) partly ascribed to the high content of long-chain (LC) n-3 PUFAs; however, not all fish types are equally rich in these components. To date, it is not clear whether the beneficial effects of fish consumption are shared by fatty and lean fish. Therefore, the aim of this meta-analysis was to synthesize knowledge regarding the relation between the intake of fatty fish or lean fish and the risk of cardiovascular events and all-cause mortality. We conducted a systematic search in PubMed, Web of Science, and Embase until May 2021 for full text with a prospective design involving humans providing data for the highest compared with the lowest fish consumption categories. Summary risk ratios (RRs) and 95% CIs were estimated using a random-effects model. Out of 1902 articles retrieved from the literature search, 19 reports met the criteria for inclusion in the meta-analysis. Altogether, studies on fatty fish comprised 1,320,596 person-years of follow-up, 20,531 incident coronary heart disease (CHD) cases, 9256 incident CVD cases, and 104,763 total deaths. Studies on lean fish comprised 937,362 person-years of follow-up, 21,636 incident CHD cases, 7315 incident CVD cases, and 16,831 total deaths. An inverse association was present for fatty fish with CHD incidence (RR: 0.92; 95% CI: 0.86, 0.97), CHD mortality (RR: 0.83; 95% CI: 0.70, 0.98), and total mortality (RR: 0.97; 95% CI: 0.94, 0.99). This was not the case for lean fish. The summary estimates for CVD incidence and mortality did not show significant association with both fatty fish and lean fish consumption. The study findings are innovative in highlighting that the health benefits so far linked to fish consumption are, in fact, driven by fatty fish.

Flaxseed Oil as a Source of Omega n-3 Fatty Acids to Improve Semen Quality from Livestock Animals: A Review

Simple Summary

In response to the conservation of threatened livestock species, different strategies to improve semen quality have been developed. However, spermatozoa remain sensitive to cryopreservation damages especially that of avian species, thus limiting the use of reproductive biotechnologies such as artificial insemination in the conservation programs. Improving semen quality through dietary inclusion of long-chain polyunsaturated fatty acids sources mainly omega n-3 has received research interest. This review explains the role of flaxseed oil as a source of omega n-3 fatty acids to improve semen quality. Comprehensive information elaborated in this review is believed to promote the use of flaxseed oil as an alternative source of omega n-3 fatty acids to fish oil. This is because fisheries are over-exploited and could collapse.

Abstract

The demand to conserve indigenous species through the cryo-gene bank is increasing. Spermatozoa remain sensitive to cryopreservation damages especially that of avian species thus limiting the use of reproductive biotechnologies such as artificial insemination in the conservation programs. Long-chain polyunsaturated fatty acid (LCPUFAs), specifically omega n-3, expanded a research interest to improve animal reproductive efficiency through improving spermatozoa quality. This is driven by the fact that mammals cannot synthesize omega-3 de-novo because they lack delta-12 and delta-15 desaturase enzymes thus supplemented in the diet is mandatory. Delta-12 and delta-15 add a double bond at the 12th and 15th carbon-carbon bond from the methyl end of fatty acids, lengthening the chain to 22 carbon molecules. Fish oil is a pioneer source of omega n-3 and n-6 fatty acids. However, there is a report that numerous fisheries are over-exploited and could collapse. Furthermore, processing techniques used for processing by-products could complement alterations of the amino acid profile and reduce protein retrieval. Alternatively, flaxseed oil contains ±52–58% of total fatty acids and lignans in the form of α-linolenic and linoleic acid. Alpha-linolenic acid (ALA,18:3n-3) is enzymatically broken-down de-novo by delta-6 desaturase and lengthened into a long-chain carbon molecule such as eicosapentaenoic acid (C20:5n-3). Nevertheless, controversial findings following the enrichment of diet with flaxseed oil have been reported. Therefore, this paper is aimed to postulate the role of flaxseed oil as an alternative source of omega n-3 and n-6 fatty acids to improve semen quality and quantity from livestock animals. These include the interaction between docosahexaenoic acid (DHA) and spermatogenesis, the interaction between docosahexaenoic acid (DHA) and testicular cells, and the effect of flaxseed oil on semen quality. It additionally assesses the antioxidants to balance the level of PUFAs in the semen.

Effects of dietary eicosapentaenoic acid and docosahexaenoic acid supplementation on metabolic syndrome: A systematic review and meta-analysis of data from 33 randomized controlled trials

BACKGROUND & AIMS

Previous randomized controlled trials (RCTs) have compared the effects of pure preparations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in reducing metabolic syndrome (MetS) risk factors, but the results were inconsistent. The present study aimed to clarify whether EPA and DHA have differential effects on MetS features in humans.

METHODS

A systematic literature search was conducted in CNKI, PubMed, Embase and Scopus updated to February 2021. The mean changes in the characteristics of MetS were calculated as weighted mean differences by using a random-effects model. Thirty-three RCTs were included.

RESULTS

The results showed that both EPA and DHA were effective at lowering serum triglycerides (TG) levels. EPA supplementation decreased the serum levels of total cholesterol (TC) (WMD = -0.24 mmol/L; 95% CI, -0.43, -0.05 mmol/L), TG (WMD = -0.77 mmol/L; 95% CI, -1.54, -0.00 mmol/L) and low density lipoprotein-cholesterol (LDL-C) (WMD = -0.13 mmol/L; 95% CI, -0.25, -0.01 mmol/L), while DHA increased the serum levels of TC (WMD = 0.14 mmol/L; 95% CI, 0.03, 0.25 mmol/L), LDL-C (WMD = 0.26 mmol/L; 95% CI, 0.15, 0.38 mmol/L) and high density lipoprotein-cholesterol (HDL-C) (WMD = 0.07 mmol/L; 95% CI, 0.04, 0.09 mmol/L). Moreover, DHA increased the serum levels of insulin compared with EPA, especially in subgroups whose mean age was <60 years (0.43 mU/L; 95% CI: 0.04, 0.81 mU/L) and duration of DHA supplementation < 3 months (0.39 mU/L; 95% CI: 0.01, 0.77 mU/L).

CONCLUSIONS

The present meta-analysis provides evidence that EPA and DHA have different effects on risk factors of MetS.

Relationship Between Composition of Fatty Acid in Platelet Phospholipid Membrane and Markers of Oxidative Stress in Healthy Men and Men After a Myocardial Infarction

Background

Oxidative stress (OS) is known to be extremely damaging for phospholipids in cell membranes, especially their polyunsaturated fatty acids (PUFAs). OS is known to be associated with increased platelet activation and thrombosis, which lead to cardiovascular lesions. The aim of this study was to investigate how changes in the composition of fatty acids (FAs) in the platelet phospholipid membrane correlate with OS in healthy men and in men who have experienced a myocardial infarction (post-MI men).

Material/Methods

FA methyl esters from the platelet phospholipid membrane of 79 apparently healthy and 20 post-MI men were identified using gas chromatography/mass spectrometry. Malondialdehyde (MDA) was measured in the blood serum using high-performance liquid chromatography, and platelet-white blood cell aggregates (PWAs) were analysed based on whole-blood flow cytometry. The composition of platelet membrane FAs was compared to MDA concentration (μg/l) and the percentage of PWA formation between healthy men and individuals who had suffered a myocardial infarction (MI).

Results

Statistically, post-MI patients had a significantly higher concentration of blood serum MDA than those in the control group (p=0.000). The level of PUFAs was also higher in the platelet phospholipid membrane of post-MI patients than in healthy individuals (p=0.016). However, the percentage of PWA formation was lower in patients compared with the control group (p<0.05).

Conclusions

A higher level of blood serum MDA concentration due to OS stimulates platelets to incorporate more PUFAs into the phospholipid membrane, thereby affecting platelet activation. This may lead the individual to develop cardiovascular diseases in the future.

Shellfish consumption and health: A comprehensive review of human studies and recommendations for enhanced public policy

Shellfish, including various species of mollusks (e.g., clams, oysters, and mussels) and crustaceans (e.g., shrimp and crab), have been a cornerstone of healthy dietary recommendations. However, beyond providing basic nutrition needs, their health-promoting effects have been suggested to include inflammation reduction and prevention of various chronic non-communicable diseases. Currently, studies on the association between shellfish consumption and health outcomes have reported conflicting results. The present comprehensive review summarized the latest studies on shellfish consumption and synthesized the available evidence on the potential health benefits or risks of shellfish consumption. The findings demonstrated that shellfish consumption may increase the risk of hyperuricemia and gout but may not increase the risk of type 2 diabetes, cardiovascular diseases, and thyroid cancer. Adequate evidence is lacking on the association between shellfish consumption and the risk of colorectal cancer, pancreatic cancer, oral cancer, endometriosis, hip fracture, cognitive function, wheeze, eczema and food allergy. Raw shellfish consumption may cause gastroenteritis and other diseases infected by bacteria or viruses. This review thus provides consumers and other relevant stakeholders with the latest evidence-based information on the potential benefits and risks of shellfish consumption.

Prevention of Endothelial Dysfunction and Cardiovascular Disease by n-3 Fatty Acids-Inhibiting Action on Oxidative Stress and Inflammation

BACKGROUND

Prospective cohort studies and randomized controlled trials have shown the protective effect of n-3 fatty acids against cardiovascular disease (CVD). The effect of n-3 fatty acids on vascular endothelial cells indicates their possible role in CVD prevention.

OBJECTIVE

Here, we describe the effect of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on endothelial dysfunction-caused by inflammation and oxidative stress-and their role in the development of CVD.

METHODS

We reviewed epidemiological studies done on n-3 fatty acids in CVD. The effect of DHA and EPA on vascular endothelial cells was examined with regard to changes in various markers, such as arteriosclerosis, inflammation, and oxidative stress, using cell and animal models.

RESULTS

Epidemiological studies revealed that dietary intake of EPA and DHA was associated with a reduced risk of various CVDs. EPA and DHA inhibited various events involved in arteriosclerosis development by preventing oxidative stress and inflammation associated with endothelial cell damage. In particular, EPA and DHA prevented endothelial cell dysfunction mediated by inflammatory responses and oxidative stress induced by events related to CVD. DHA and EPA also increased eNOS activity and induced nitric oxide production.

CONCLUSION

The effects of DHA and EPA on vascular endothelial cell damage and dysfunction may involve the induction of nitric oxide, in addition to antioxidant and anti-inflammatory effects. n-3 fatty acids inhibit endothelial dysfunction and prevent arteriosclerosis. Therefore, the intake of n-3 fatty acids may prevent CVDs, like myocardial infarction and stroke.

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.

In Vivo Digestion of Egg Products Enriched with DHA: Effect of the Food Matrix on DHA Bioavailability

The aim of the present study was to determine to what extent the food matrix could affect the release of docosahexaenoic acid (DHA) during digestion and its incorporation into systemic circulation. In this aim, three DHA-enriched egg products having the same composition but different structure were developed: omelet, hard-boiled egg, and mousse. Then, nine pigs fitted with T-shape cannulas at duodenal level and a jugular venous catheter were fed with the DHA-enriched egg products, and duodenal effluents and plasma were collected throughout the postprandial period. Results highlighted an undeniable effect of the food matrix on digestion parameters and DHA bioavailability. The transit of DHA and protein through the duodenum was faster after the ingestion of the mousse than after the ingestion of the omelet and hard-boiled egg. While most of the DHA and protein ingested under the form of mousse had already passed through the duodenum 4.5 h after its ingestion, significantly higher quantities were still present in the case of the omelet and hard-boiled egg. In terms of bioavailability, the omelet was the most efficient vector for delivering DHA into systemic circulation. It supplied 56% and 120% more DHA than the hard-boiled egg and the mousse, respectively.

Novel high-docosahexaenoic-acid tuna oil supplementation modulates gut microbiota and alleviates obesity in high-fat diet mice

Studies have documented the benefits of fish oil in different diseases because of its high n-3 polyunsaturated fatty acid content. However, these studies mostly used commercially available fish oil supplements with a ratio of 18/12 for eicosapentaenoic acid and docosahexaenoic acid (DHA). However, increasing DHA content for this commonly used ratio might bring out a varied metabolic effect, which have remained unclear. Thus, in this study, a novel tuna oil (TO) was applied to investigate the effect of high-DHA content on the alteration of the gut microbiota and obesity in high-fat diet mice. The results suggest that high-DHA TO (HDTO) supplementation notably ameliorates obesity and related lipid parameters and restores the expression of lipid metabolism-related genes. The benefits of TOs were derived from their modification of the gut microbiota composition and structure in mice. A high-fat diet triggered an increased Firmicutes/Bacteroidetes ratio that was remarkably restored by TOs. The number of obesity-promoting bacteria-Desulfovibrio, Paraeggerthella, Terrisporobacter, Millionella, Lachnoclostridium, Anaerobacterium, and Ruminiclostridium-was dramatically reduced. Desulfovibrio desulfuricans, Alistipes putredinis, and Millionella massiliensis, three dysbiosis-related species, were especially regulated by HDTO. Regarding the prevention of obesity, HDTO outperforms the normal TO. Intriguingly, HDTO feeding to HFD-fed mice might alter the arginine and proline metabolism of intestinal microbiota.

Minimizing marine ingredients in diets of farmed Atlantic salmon (Salmo salar): effects on liver and head kidney lipid class and fatty acid composition

Limited fish meal and fish oil supplies have necessitated research on alternatives for aquafeeds. Seven dietary treatments with different protein and lipid sources were formulated for farmed Atlantic salmon, and their effects on liver and head kidney lipid class, fatty acid, and elemental composition were studied. Fish meal, fish oil, and EPA + DHA content ranged from 5-35%, 0-12%, and 0.1-3%, respectively. Elemental analysis showed that the C to N ratio was higher in the head kidney than in the liver, which is consistent with higher content of total lipids in the head kidney compared with the liver. There was a greater susceptibility to dietary lipid alterations in the liver compared with the head kidney despite liver having a greater proportion of phospholipid and a much lower proportion of triacylglycerol. So long as fish oil levels were 5% or more of the diet, arachidonic acid (ARA) and docosahexaenoic acid (DHA) proportions were the same for each tissue as with feeding the marine diet with 12% fish oil; however, livers and head kidneys from fish fed the lowest amount of fish meal and fish oil had the lowest levels of eicosapentaenoic (EPA) and DHA and the highest ARA levels. Removal of fish oil and reduction of fish meal to 5% in diets of farmed Atlantic salmon affected elemental and lipid compositions of the liver and head kidney tissues potentially increasing susceptibility to inflammation. However, with 10% of the diet comprising fish meal and fish oil, lipid contents were comparable with fish fed marine-based diets.

Oxidative Stress in Endurance Cycling Is Reduced Dose-Dependently after One Month of Re-Esterified DHA Supplementation

Docosahexaenoic acid (DHA) supplementation can reduce exercise-induced oxidative stress generated during long aerobic exercise, with the minimum dose yet to be elucidated for physically active subjects. In this study, we performed a dose finding with re-esterified DHA in triglyceride form in a randomized double-blind parallel trial at different doses (350, 1050, 1750, and 2450 mg a day) for 4 weeks in males engaged in regular cycling (n = 100, 7.6 ± 3.7 h/week). The endogenous antioxidant capacity of DHA was quantified as a reduction in the levels of the oxidative stress marker 8-hydroxy-2′-deoxyguanosine (8-OHdG) recollected in 24-h urine samples after 90 min of constant load cycling before and after intervention. To ascertain incorporation of DHA, erythrocyte polyunsaturated fatty acid (PUFA) composition was compared along groups. We found a dose-dependent antioxidant capacity of DHA from 1050 mg with a trend to neutralization for the highest dose of 2450 mg (placebo: n = 13, F = 0.041; 350 mg: n = 10, F = 0.268; 1050 mg: n = 11, F = 7.112; 1750 mg: n = 12, F = 9.681; 2450 mg: n = 10, F = 15.230). In the erythrocyte membrane, the re-esterified DHA increased DHA and omega-3 percentage and decreased omega 6 and the omega-6 to omega-3 ratio, while Eicosapentaenoic acid (EPA) and PUFA remained unchanged. Supplementation of re-esterified DHA exerts a dose-dependent endogenous antioxidant property against moderate-intensity long-duration aerobic exercise in physically active subjects when provided at least 1050 mg a day for 4 weeks.

Re-esterified DHA improves ventilatory threshold 2 in competitive amateur cyclists

Background

Fish oils were studied as ergogenic aids in a number of mixed physical trial designs showing promising results. However, the heterogeneous purity of the studied supplements, combined with the variety of physical tests employed call for more studies to confirm these findings, ideally with standardised supplements. Our aim was to test a supplement highly concentrated in DHA (DHA:EPA ratio equal to approximately 8:1) on a maximal cycling test to elucidate performance improvements mainly due to DHA.

Methods

A double-blind, placebo controlled, randomised balanced, parallel design, in competitive amateur cyclists was employed. They were all male, older than 18 years old, with training routine of 2 to 4 sessions per week lasting at least one hour each. A ramp cycling test to exhaustion with a subsequent 5 min recovery phase was employed before and after treatment to analyse aerobic metabolism and lactate clearance after the bout. After 30 days of supplementation with 975 mg of re-esterified DHA, the thirty-eight cyclist who completed the study were finally included for statistical analysis.

Results

Mean power output at ventilatory threshold 2 (VT2) improved after DHA supplementation both as absolute (△DHA versus △PLA: 6.33–26.54 Watts; CI 95%) and relative (p=0.006) values, paralleled with higher oxygen consumption at VT2 both for absolute (DHA 2729.4 ±304.5, 3045.9 ±335.0; PLA 2792.3 ±339.5, 2845.5 ±357.1; ml·min⁻¹ baseline versus post p=0.025) and relative values (DHA 36.6 ±5.0, 41.2 ±5.4; PLA 37.2 ±5.7, 38.1 ±5.2; ml·kg⁻¹·min⁻¹ baseline versus post p=0.024). Heart rate recovery rate improved during the recovery phase in the DHA group compared to PLA (p=0.005).

Conclusion

DHA is capable of improving mean power output at the ventilatory threshold 2 (anaerobic ventilatory threshold) in amateur competitive cyclists. It is unclear if these findings are the result of the specific DHA supplement blend or another factor.

Higher omega-3 index after dietary inclusion of omega-3 phospholipids versus omega-3 triglycerides in Alaskan Huskies

Background and Aim

Numerous studies have found benefits of omega-3 polyunsaturated fatty acids (PUFAs), namely, for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in dogs. The objective of the present study was to assess the efficacy of dietary inclusion of equal amounts of omega-3 FAs in phospholipid (PL) from krill meal to triglyceride structure from fish oil to increase the omega-3 FA profile in red blood cells (RBCs) in dogs.

Materials and Methods

Ten adult Alaskan Huskies of both genders were supplemented with daily 1.7 g EPA and DHA from krill meal for 6 weeks, while another ten dogs received 1.7 g EPA and DHA from fish oil. FA and omega-3 index measurements of the two groups were taken after 0, 3, and 6 weeks for comparison.

Results

It was mainly the EPA levels that increased in the krill meal group (from 1.84% to 4.42%) compared to the fish oil group (from 1.90% to 2.46%) (p<0.001), which drove the group differences in the omega-3 index. This resulted in the krill meal group having a mean omega-3 index increase from 3.9 at baseline to 6.3%, which was significantly greater than the increase from 3.9% to 4.7% observed in the fish oil group (p<0.001). Concomitantly, omega-6 PUFAs, such as arachidonic acid and linoleic acid, were reduced in RBC membranes and the omega-6 to omega-3 ratio was significantly more reduced in the krill meal compared to the fish oil group.

Conclusion

The results showed that krill meal supplementation was associated with a reduction of omega-6 PUFAs, which compensated for the increased omega-3 index, suggesting that PLs are efficient delivery molecules of omega-3 PUFAs.

The Effects of Linoleic Acid Consumption on Lipid Risk Markers for Cardiovascular Disease in Healthy Individuals: A Review of Human Intervention Trials

Cardiovascular disease (CVD) is the leading cause of death worldwide. Risk factors for developing this disease include high serum concentrations of total cholesterol, triglycerides, low-density lipoproteins, very-low density lipoproteins, and low concentrations of high-density lipoproteins. One proposed dietary strategy for decreasing risk factors involves replacing a portion of dietary saturated fatty acids with mono- and polyunsaturated fatty acids (PUFAs). The essential omega-6 PUFA, linoleic acid (LA), is suggested to decrease the risk for CVD by affecting these lipid risk markers. Reviewing human intervention trials will provide further evidence of the effects of LA consumption on risk factors for CVD. PubMed was used to search for peer-reviewed articles. The purpose of this review was: (1) To summarize human intervention trials that studied the effects of LA consumption on lipid risk markers for CVD in healthy individuals, (2) to provide mechanistic details, and (3) to provide recommendations regarding the consumption of LA to decrease the lipid risk markers for CVD. The results from this review provided evidence that LA consumption decreases CVD lipid risk markers in healthy individuals.

The skeletal muscles of mice infected with Plasmodium berghei and Plasmodium chabaudi reveal a crosstalk between lipid mediators and gene expression

Background

Malaria is one of the most prevalent infectious disease in the world with 3.2 billion humans at risk. Malaria causes splenomegaly and damage in other organs including skeletal muscles. Skeletal muscles comprise nearly 50% of the human body and are largely responsible for the regulation and modulation of overall metabolism. It is essential to understand how malaria damages muscles in order to develop effective preventive measures and/or treatments. Using a pre-clinical animal model, the potential molecular mechanisms of Plasmodium infection affecting skeletal muscles of mice were investigated.

Methods

Mouse Signal Transduction Pathway Finder PCR Array was used to monitor gene expression changes of 10 essential signalling pathways in skeletal muscles from mice infected with Plasmodium berghei and Plasmodium chabaudi. Then, a new targeted-lipidomic approach using liquid chromatography with tandem mass spectrometry (LC–MS/MS) to profile 158 lipid signalling mediators (LMs), mostly eicosanoids derived from arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), was applied. Finally, 16 key LMs directly associated with inflammation, oxidative stress, and tissue healing in skeletal muscles, were quantified.

Results

The results showed that the expression of key genes altered by Plasmodium infection is associated with inflammation, oxidative stress, and atrophy. In support to gene profiling results, lipidomics revealed higher concentrations of LMs in skeletal muscles directly related to inflammatory responses, while on the levels of LMs crucial in resolving inflammation and tissue repair reduced significantly.

Conclusion

The results provide new insights into the molecular mechanisms of malaria-induced muscle damage and revealed a potential mechanism modulating inflammation in malarial muscles. These pre-clinical studies should help with future clinical studies in humans aimed at monitoring of disease progression and development of specific interventions for the prevention and mitigation of long-term chronic effects on skeletal muscle function.

SC411 treatment can enhance survival in a mouse model of sickle cell disease

Sickle cell disease (SCD) is one of the most common inherited blood disorder among African Americans affecting 70,000-100,000 individuals in the United States. It is characterized by abnormal hemoglobin (HbS) which develops into severe hemolytic anemia and vaso-occlusive crisis. Therefore, patients with SCD suffer from a chronic state of inflammation, which is responsible for multiple organ damage, ischemic attacks, and premature death. Another major hallmark of SCD patients is the abnormally low levels of omega-3 fatty acids, especially docosahexaenoic acid (DHA) in their red blood cell membranes. Treatment with DHA can reduce red blood cell adhesion and enhance cerebral blood flow, thus, our main goal is to investigate the effect of SC411, which is a novel, highly purified DHA ethyl ester formulation with a proprietary delivery platform in SCD. Utilizing a transgenic mouse model of SCD (HbSS-Townes) and recurrent hypoxic challenges (10%O₂, 0.5% CO₂ and balance N₂ for 3 h) to mimic ischemic-like conditions, our data suggest that SC411 can elevate blood DHA and eicosapentaenoic acid (EPA) levels after 8 weeks of treatment. SC411 can also decrease arachidonic acid (AA) and sickling of red blood cells. In addition, SC411-treated SCD mice showed presented with cerebral blood flow, alleviated neuroinflammation, and revived working memory which ultimately enhanced overall survival. In summary, this study suggests that treatment with SC411 improves cellular and functional outcomes in SCD mice. This finding may provide novel therapeutic opportunities in the treatment against ischemic injury elicited by SCD.

High-added value products from microalgae and prospects of aquaculture wastewaters as microalgae growth media

Aquaculture plays an important role in human nutrition and economic development but is often expanded to the detriment of the natural environment. Several research projects, aimed at cultivating microalgae in aquaculture wastewaters (AWWs) to reduce organic loads and minerals, along with the production of microalgal cell mass and metabolic products, are underway. Microalgal cell mass is of high nutritional value and is regarded as a candidate to replace, partially at least, the fish meal in the fish feed. Also, microalgal cell mass is considered as a feedstock in the bio-fuel manufacture, as well as a source of high-added value metabolic products. The production of these valuable products can be combined with the reuse of AWWs in the light of environmental concerns related with the aquaculture sector. Many research papers published in the last decade demonstrate that plenty of microalgae species are able to efficiently grow in AWWs, mainly derived from fish and shrimp farms, and produce valuable metabolites reducing the AWW pollutant load. We conclude that bio-remediation of AWWs combining with the production of microalgae cell mass and specific metabolites is probably the most convenient and economical solution for AWWs management and can contribute to the sustainable growth of the aquaculture.

A biphasic system based on guanidinium ionic liquid: Preparative separation of eicosapentaenoic acid ethyl ester and docosahexaenoic acid ethyl ester by countercurrent chromatography

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are high nutritional components. Evidence for unique effects of them is increasing. Further understanding of their independent biological functions urgently needs more efficient separation techniques. Nowadays, most of the commercially available fish oil products are the mixture of eicosapentaenoic acid ethyl ester (EPAEE) and docosahexaenoic acid ethyl ester (DHAEE). It will be convenient to directly separate esterified EPA and DHA without saponification pretreatment. However, it is of great challenge to separate EPAEE and DHAEE because of their extremely fat-soluble nature and the equivalent chain length rule. In this research, the suitability of green guanidinium ionic liquid (IL) in countercurrent chromatography (CCC) solvent system for the separation of them was evaluated for the first time. Compared with imidazolium IL and phosphonium IL, guanidinium IL based non-aqueous biphasic system showed more outstanding separation performance. The separation mechanism was elucidated in depth through quantum mechanical calculations. It was found that guanidinium IL acted a crucial role in the CCC separation, which resulted in difference of partition behavior of EPAEE and DHAEE via different hydrogen-bonding affinity. EPAEE and DHAEE were successfully separated by solvent system (n-heptane/methanol/propylguanidinium chloride ([C₃Gun]Cl, 1:1:5%, v/v/m)) with high purity (>95%) in one step, which was not achieved beforehand. Moreover, an easy recycling procedure of IL had also been devised, which significantly reduced waste generated. It opens up a new way for reasonable design water-free two-phase solvent system for efficient separation of very non-polar lipid compounds.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Metabolic indices of polyunsaturated fatty acids: current evidence, research controversies, and clinical utility

The n-3 and n-6 polyunsaturated fatty acids (PUFA) are among the most studied nutrients in human metabolism. In the past few decades, prospective studies and controlled trials have supported the view that the effects of these essential fatty acids are clinically relevant. PUFA profiles in different blood compartments are reflections of both diet and metabolism, and their levels may be related to disease risk. Despite widespread interest, there is no consensus regarding which biomarkers best reflect PUFA status in the body. The measurement of PUFA levels is not straight-forward, and a wide variety of indices have been used in clinical studies, producing conflicting results. A major source of heterogeneity among studies is associated with research design, sampling, and laboratory analyses. To date, the n-3 index, n-6/n-3 ratio, and arachidonic acid (AA)/eicosapentaenoic acid (EPA) ratio are the most promising biomarkers associated with PUFA metabolism. Although hotly debated, these indices may be considered at least markers, if not risk factors, for several diseases, especially cardiovascular events and brain disorders. Here, we summarize the most updated evidence of n-3 and n-6 PUFA effects on human health, reviewing current controversies on the aforementioned indices and whether they can be considered valuable predictors of clinical outcomes.

The association of fish consumption and its urinary metabolites with cardiovascular risk factors: the International Study of Macro-/Micronutrients and Blood Pressure (INTERMAP)

BACKGROUND

Results from observational studies regarding associations between fish (including shellfish) intake and cardiovascular disease risk factors, including blood pressure (BP) and BMI, are inconsistent.

OBJECTIVE

To investigate associations of fish consumption and associated urinary metabolites with BP and BMI in free-living populations.

METHODS

We used cross-sectional data from the International Study of Macro-/Micronutrients and Blood Pressure (INTERMAP), including 4680 men and women (40-59 y) from Japan, China, the United Kingdom, and United States. Dietary intakes were assessed by four 24-h dietary recalls and BP from 8 measurements. Urinary metabolites (2 timed 24-h urinary samples) associated with fish intake acquired from NMR spectroscopy were identified. Linear models were used to estimate BP and BMI differences across categories of intake and per 2 SD higher intake of fish and its biomarkers.

RESULTS

No significant associations were observed between fish intake and BP. There was a direct association with fish intake and BMI in the Japanese population sample (P trend = 0.03; fully adjusted model). In Japan, trimethylamine-N-oxide (TMAO) and taurine, respectively, demonstrated area under the receiver operating characteristic curve (AUC) values of 0.81 and 0.78 in discriminating high against low fish intake, whereas homarine (a metabolite found in shellfish muscle) demonstrated an AUC of 0.80 for high/nonshellfish intake. Direct associations were observed between urinary TMAO and BMI for all regions except Japan (P < 0.0001) and in Western populations between TMAO and BP (diastolic blood pressure: mean difference 1.28; 95% CI: 0.55, 2.02 mmHg; P = 0.0006, systolic blood pressure: mean difference 1.67; 95% CI: 0.60, 2.73 mmHg; P = 0.002).

CONCLUSIONS

Urinary TMAO showed a stronger association with fish intake in the Japanese compared with the Western population sample. Urinary TMAO was directly associated with BP in the Western but not the Japanese population sample. Associations between fish intake and its biomarkers and downstream associations with BP/BMI appear to be context specific. INTERMAP is registered at www.clinicaltrials.gov as NCT00005271.