Seafood Long-Chain n-3 Polyunsaturated Fatty Acids and Cardiovascular Disease: A Science Advisory From the American Heart Association

Controversies in the Use of Omega-3 Fatty Acids to Prevent Atherosclerosis

PURPOSE OF REVIEW

We discuss current controversies in the clinical use of omega-3 fatty acids (FA), primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and examine discrepancies between recent trials. Furthermore, we discuss potential side effects reported in these studies and the role of mixed omega-3 FA dietary supplements and concerns about their use.

RECENT FINDINGS

REDUCE-IT showed that addition of icosapent ethyl, a highly purified form of EPA, can reduce risk of cardiovascular events among statin-treated individuals with high triglycerides. Additional supportive evidence for EPA has come from other trials and meta-analyses of omega-3 FA therapy. In contrast, trials of mixed EPA/DHA products have consistently failed to improve cardiovascular outcomes. Discrepancies in results reported in RCTs could be explained by differences in omega-3 FA products, dosing, study populations, and study designs including the placebo control formulation. Evidence obtained from highly purified forms should not be extrapolated to other mixed formulations, including "over-the-counter" omega-3 supplements. Targeting TG-rich lipoproteins represents a new frontier for mitigating ASCVD risk. Clinical and basic research evidence suggests that the use of omega-3 FA, specifically EPA, appears to slow atherosclerosis by reducing triglyceride-rich lipoproteins and/or inflammation, therefore addressing residual risk of clinical ASCVD.

Valorization of Side Stream Products from Sea Cage Fattened Bluefin Tuna (Thunnus thynnus): Production and In Vitro Bioactivity Evaluation of Enriched ω-3 Polyunsaturated Fatty Acids

The valorization of side streams from fishery and aquaculture value-chains is a valuable solution to address one of the challenges of the circular economy: turning wastes into profit. Side streams produced after filleting of sea cage fattened bluefin tuna (Thunnus thynnus) were analyzed for proximate composition and fatty acid profile to evaluate the possibility of producing tuna oil (TO) as a valuable source of ω-3 polyunsaturated fatty acids (PUFA) and testing its bioactivity in vitro. Ethyl esters of total fatty acids (TFA), obtained from TO, were pre-enriched by urea complexation (PUFA-Ue) and then enriched by short path distillation (SPD) up to almost 85% of the PUFA fraction (PUFA-SPe). The bioactivity of TFA, PUFA-SPe, and ethyl esters of depleted PUFA (PUFA-SPd) were tested in vitro, through analysis of lipid metabolism genes, in gilthead sea bream (Sparus aurata) fibroblast cell line (SAF-1) exposed to oils. TFA and PUFA-SPd upregulated transcription factors (pparβ and pparγ) and lipid metabolism-related genes (D6D, fas, fabp, fatp1, and cd36), indicating the promotion of adipogenesis. PUFA-SPe treated cells were similar to control. PUFA-SPe extracted from farmed bluefin tuna side streams could be utilized in fish feed formulations to prevent excessive fat deposition, contributing to improving both the sustainability of aquaculture and the quality of its products.

Scientific advice related to nutrient profiling for the development of harmonised mandatory front-of-pack nutrition labelling and the setting of nutrient profiles for restricting nutrition and health claims on foods

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver scientific advice related to nutrient profiling for the development of harmonised mandatory front‐of‐pack nutrition labelling and the setting of nutrient profiles for restricting nutrition and health claims on foods. This Opinion is based on systematic reviews and meta‐analyses of human studies on nutritionally adequate diets, data from the Global Burden of Disease framework, clinical practice guidelines, previous EFSA opinions and the priorities set by EU Member States in the context of their Food‐Based Dietary Guidelines and associated nutrient/food intake recommendations. Relevant publications were retrieved through comprehensive searches in PubMed. The nutrients included in the assessment are those likely to be consumed in excess or in inadequate amounts in a majority of European countries. Food groups with important roles in European diets have been considered. The Panel concludes that dietary intakes of saturated fatty acids (SFA), sodium and added/free sugars are above, and intakes of dietary fibre and potassium below, current dietary recommendations in a majority of European populations. As excess intakes of SFAs, sodium and added/free sugars and inadequate intakes of dietary fibre and potassium are associated with adverse health effects, they could be included in nutrient profiling models. Energy could be included because a reduction in energy intake is of public health importance for European populations. In food group/category‐based nutrient profiling models, total fat could replace energy in most food groups owing to its high‐energy density, while the energy density of food groups with low or no fat content may be well accounted for by the inclusion of (added/free) sugars. Some nutrients may be included in nutrient profiling models for reasons other than their public health importance, e.g. as a proxy for other nutrients of public health importance, or to allow for a better discrimination of foods within the same food category.

Greater Adherence to Dietary Guidelines Associated with Reduced Risk of Cardiovascular Diseases in Chinese Patients with Type 2 Diabetes

The evidence regarding the impact of the scores on healthy eating indices on the risk of cardiovascular events among patients with type 2 diabetes (T2D) is limited. As such, in this study, we examined the associations of adherence to the Chinese and American dietary guidelines and the risk of cardiovascular disease (CVD) among Chinese individuals with T2D. We conducted a 1:1 age- and sex-matched case−control study based on a Chinese population. We used a structured questionnaire and a validated 79-item food-frequency questionnaire to collect general information and dietary intake information, and calculated the Chinese Healthy Eating Index (CHEI) and the Healthy Eating Index-2015 (HEI-2015). As participants, we enrolled a total of 419 pairs of hospital-based CVD cases and controls, all of whom had T2D. We found a significant inverse association between diet quality scores on the CHEI and HEI-2015 and the risk of CVD. The adjusted odds ratios (95% confidence interval) per five-score increment were 0.68 (0.61, 0.76) in the CHEI and 0.60 (0.52, 0.70) in the HEI-2015. In stratified analyses, the protective associations remained significant in the subgroups of sex, BMI, smoking status, tea-drinking, hypertension state, dyslipidemia state, T2D duration, and medical nutrition therapy knowledge (all p < 0.05). These findings suggest that a higher CHEI or HEI-2015 score, representing a higher-quality diet relative to the most recent Chinese or American dietary guidelines, was associated with a decreased risk of CVD among Chinese patients with T2D.

Docosahexaenoic acid supplementation represses the early immune response against murine cytomegalovirus but enhances NK cell effector function

BACKGROUND

Docosahexaenoic acid (DHA) supplementation is beneficial for several chronic diseases; however, its effect on immune regulation is still debated. Given the prevalence of cytomegalovirus (CMV) infection and because natural killer (NK) cells are a component of innate immunity critical for controlling CMV infection, the current study explored the effect of a DHA-enriched diet on susceptibility to murine (M) CMV infection and the NK cell effector response to MCMV infection.

RESULTS

Male C57BL/6 mice fed a control or DHA-enriched diet for 3 weeks were infected with MCMV and sacrificed at the indicated time points postinfection. Compared with control mice, DHA-fed mice had higher liver and spleen viral loads at day 7 postinfection, but final MCMV clearance was not affected. The total numbers of NK cells and their terminal mature cell subset (KLRG1⁺ and Ly49H⁺ NK cells) were reduced compared with those in control mice at day 7 postinfection but not day 21. DHA feeding resulted in higher IFN-γ and granzyme B expression in splenic NK cells at day 7 postinfection. A mechanistic analysis showed that the splenic NK cells of DHA-fed mice had enhanced glucose uptake, increased CD71 and CD98 expression, and higher mitochondrial mass than control mice. In addition, DHA-fed mice showed reductions in the total numbers and activation levels of CD4⁺ and CD8⁺ T cells.

CONCLUSIONS

These results suggest that DHA supplementation represses the early response to CMV infection but preserves NK cell effector functions by improving mitochondrial activity, which may play critical roles in subsequent MCMV clearance.

Comprehensive Analysis of Fatty Acid and Oxylipin Patterns in n3-PUFA Supplements

Supplementing long-chain omega-3 polyunsaturated fatty acids (n3-PUFA) improves health. We characterized the pattern of total and non-esterified oxylipins and fatty acids in n3 supplements made of fish, krill, or micro-algae oil by LC-MS. All supplements contained the declared amount of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); however, their content per capsule and the concentration of other fatty acids varied strongly. Krill oil contained the highest total n3 oxylipin concentration (6000 nmol/g) and the highest degree of oxidation (EPA 0.7%; DHA 1.3%), while micro-algae oil (Schizochytrium sp.) showed the lowest oxidation (<0.09%). These oils contain specifically high amounts of the terminal hydroxylation product of EPA (20-HEPE, 300 nmol/g) and DHA (22-HDHA, 200 nmol/g), which can serve as an authenticity marker for micro-algae oil. Refined micro-algae and fish oil were characterized by NEFA levels of ≤0.1%. Overall, the oxylipin and fatty acid pattern allows gaining new insights into the origin and quality of n3-PUFA oils in supplements.

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

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

Long-chain omega-3 polyunsaturated fatty acids and the risk of heart failure

Aims:

Adequate intake of long-chain (LC) omega-3 polyunsaturated fatty acids ( n-3 PUFAs) is considered important for cardiovascular health. However, the effects of LC n-3 PUFAs on the risk of heart failure (HF) remain unclear. This systematic review and meta-analysis aimed to determine the role of LC n-3 PUFAs in the incidence of HF.

Materials and Methods:

Electronic databases were searched for studies up to 31 July 2021. Studies were included for the meta-analysis if they reported the adjusted associations between different dietary intakes or circulating concentrations of LC n-3 PUFAs and the risk of HF. A random-effect model was used to calculate the pooled estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for higher LC n-3 PUFA concentrations.

Results:

Thirteen studies were included in the meta-analysis. Eight studies comprising 316,698 individuals (11,244 incident HF cases), with a median follow-up of 10.7 years, showed that a higher dietary intake of LC n-3 PUFAs was associated with a lower risk of HF (highest versus lowest quintile: HR = 0.84, 95% CI = 0.75–0.94). Six studies, comprising 17,163 participants (2520 HF cases) with a median follow-up of 9.7 years, showed that higher circulating LC n-3 PUFA concentrations were associated with a lower risk of HF (highest versus lowest quintile: HR = 0.59, 95% CI = 0.39–0.91). Higher circulating docosahexaenoic acid concentrations were associated with a decreased risk of HF (top versus bottom quintile: HR = 0.44, 95% CI = 0.26–0.77). The associations between eicosapentaenoic acid (HR = 0.58, 95% CI = 0.26–1.25), docosahexaenoic acid (HR = 0.66, 95% CI = 0.24–1.82), and the risk of HF were not significant.

Conclusion:

High LC n-3 PUFA concentrations measured by dietary intake or circulating biomarkers are associated with a lower risk of developing HF.

Effects of Grazing Season on Physico-Chemical Characteristics and Fatty Acids of Nutritional Interest of Caciocavallo Palermitano Cheese

The aim of this work was to evaluate, in the different production seasons of the year, the physico-chemical quality of an artisanal cheese traditionally obtained from autochthonous grazing cows, with particular reference to fatty acids (FA) of nutritional interest that play an important role in the risk or prevention of some human pathologies. For this purpose, cheeses were sampled in 11 farms, repeating the samplings in 3 different periods of the year (summer, autumn–winter, and spring) when the productive conditions of the pastures varied. The cheeses produced in the spring period, when cows ingest a greater amount of grazed forage, resulted in a more adequate composition of the main FA, which are recognized as having a health effect, such as α-linolenic, trans-vaccenic, rumenic, docosapentaenoic (DPA) and docosahexaenoic (DHA) acids. Branched-chain FA were found in greater quantities in spring cheeses, as well as in summer ones. The FA composition of cheeses produced in the different seasons was reflected in some nutritional indexes that also resulted as more suitable in cheeses obtained in the spring period. The positive effects induced on the FA profile of cheeses are presumably linked to the diet of autochthonous cows, which is mainly based on forage from natural pastures. Therefore, the results obtained confirm the benefits of grazing, which is able to guarantee the production of healthier cheeses for consumers.

The Omega-3 Index Response to an 8 Week Randomized Intervention Containing Three Fatty Fish Meals Per Week Is Influenced by Adiposity in Overweight to Obese Women

Background

The Dietary Guidelines for Americans (DGA) recommends consuming ~225 g/wk of a variety of seafood providing &gt;1.75 g/wk of long-chain omega-3 fatty acids to reduce cardiovascular disease risk, however individual responses to treatment vary.

Objective

This study had three main objectives. First, to determine if a DGA-conforming diet (DGAD), in comparison to a typical American diet (TAD), can increase the omega-3 index (OM3I), i.e., the red blood cell mol% of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA). Second, to identify factors explaining variability in the OM3I response to dietary treatment. Third to identify factors associated with the baseline OM3I.

Design

This is a secondary analysis of a randomized, double-blind 8 wk dietary intervention of overweight/obese women fed an 8d rotating TAD (n = 20) or DGAD (n = 22) registered at www.clinicaltrials.gov as NCT02298725. The DGAD-group consumed 240 g/wk of Atlantic farmed salmon and albacore tuna in three meals with an estimated EPA + DHA of 3.7 ± 0.6 g/wk. The TAD-group consumed ~160 g/wk of farmed white shrimp and a seafood salad containing imitation crab in three meal with an estimated EPA + DHA of 0.45 ± 0.05 g/wk. Habitual diet was determined at baseline, and body composition was determined at 0 and 8wks. Red blood cell fatty acids were measured at 0, 2 and 8 wk.

Results

At 8 wk, the TAD-group OM3I was unchanged (5.90 ± 1.35–5.80 ± 0.76%), while the DGAD-group OM3I increased (5.63 ± 1.27–7.33 ± 1.36%; p &lt; 0.001). In the DGAD-group 9 of 22 participants achieved an OM3I &gt;8%. Together, body composition and the baseline OM3I explained 83% of the response to treatment variability. Baseline OM3I (5.8 ± 1.3%; n = 42) was negatively correlated to the android fat mass (p = 0.0007) and positively correlated to the FFQ estimated habitual (EPA+DHA) when expressed as a ratio to total dietary fat (p = 0.006).

Conclusions

An 8 wk TAD did not change the OM3I of ~6%, while a DGAD with 240 g/wk of salmon and albacore tuna increased the OM3I. Body fat distribution and basal omega-3 status are primary factors influencing the OM3I response to dietary intake in overweight/obese women.

Circulating trimethylamine N-oxide levels following fish or seafood consumption

PURPOSE

Some species of fish and seafood are high in trimethylamine N-oxide (TMAO), which accumulates in muscle where it protects against pressure and cold. Trimethylamine (TMA), the metabolic precursor to TMAO, is formed in fish during bacterial spoilage. Fish intake is promoted for its potential cardioprotective effects. However, numerous studies show TMAO has pro-atherothrombotic properties. Here, we determined the effects of fish or seafood consumption on circulating TMAO levels in participants with normal renal function.

METHODS

TMAO and omega-3 fatty acid content were quantified across multiple different fish or seafood species by mass spectrometry. Healthy volunteers (n = 50) were recruited for three studies. Participants in the first study consented to 5 consecutive weekly blood draws and provided dietary recall for the 24 h preceding each draw. In the second study, TMAO levels were determined following defined low and high TMAO diets. Finally, participants consumed test meals containing shrimp, tuna, fish sticks, salmon or cod. TMAO levels were quantified by mass spectrometry in blood collected before and after dietary challenge.

RESULTS

TMAO + TMA content varied widely across fish and seafood species. Consumption of fish sticks, cod, and to a lesser extent salmon led to significant increases in circulating TMAO levels. Within 1 day, circulating TMAO concentrations in all participants returned to baseline levels.

CONCLUSIONS

We conclude that some fish and seafood contain high levels of TMAO, and may induce a transient elevation in TMAO levels in some individuals. Selection of low TMAO content fish is prudent for subjects with elevated TMAO, cardiovascular disease or impaired renal function.

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.

Differential Effects of EPA and DHA on PPARγ-mediated Sympathetic Innervation in Infarcted Rat Hearts by GPR120-dependent and -independent Mechanisms

The ω-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been shown to attenuate inflammation processes, whereas, the molecular mechanisms remain unclear. This study was aimed at figuring out the differential effects of EPA and DHA on fatal arrhythmias and whether the signaling pathway could be a target after myocardial infarction, an inflammatory status. Male Wistar rats after ligating coronary artery were randomized to either vehicle, EPA, or DHA for 4 weeks. Postinfarction was associated with increased myocardial norepinephrine levels and sympathetic innervation. Furthermore, infarction was associated with the activation of NLRP3 inflammasomes and increased the protein and expression of IL-1β and nerve growth factor (NGF). These changes were blunted after adding either EPA or DHA with a greater extent of EPA than DHA. Immunoblotting and immunohistochemical analysis showed that EPA had significantly lower phosphorylation of PPARγ at Ser 112 compared with DHA. Arrhythmic severity during programmed stimulation in the infarcted rats treated with EPA was significantly lower than those treated with DHA. Specific inhibition of GPR120 by AH-7614 and PPARγ by T0070907 reduced the EPA-or DHA-related attenuation of IL-1β and NGF release. Besides, AH-7614 treatment partially reduced the PPARγ levels, whereas, T0070907 administration did not affect the GPR120 levels. These results suggest that EPA was more effective than DHA in prevention of fatal arrhythmias by inhibiting NLRP3 inflammasome and sympathetic innervation through activation of PPARγ-mediated GPR120-dependent and -independent signaling pathways in infarcted hearts.

Biomonitoring of exposure to Great Lakes contaminants among licensed anglers and Burmese refugees in Western New York: Toxic metals and persistent organic pollutants, 2010-2015

Between 2010 and 2015, the New York State Department of Health (NYSDOH) conducted a biomonitoring program to gather exposure data on Great Lakes contaminants among licensed anglers and Burmese refugees living in western New York who ate locally caught fish. Four hundred and nine adult licensed anglers and 206 adult Burmese refugees participated in this program. Participants provided blood and urine samples and completed a detailed questionnaire. Herein, we present blood metal levels (cadmium, lead, and total mercury) and serum persistent organic pollutant concentrations [polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dichlorodiphenyldichloroethylene (DDE), and trans-nonachlor]. Multiple linear regression was applied to investigate the associations between analyte concentrations and indicators of fish consumption (locally caught fish meals, store-bought fish meals, and consuming fish/shellfish in the past week). Licensed anglers consumed a median of 16 locally caught fish meals and 22 store-bought fish meals while Burmese refugees consumed a median of 106 locally caught fish meals and 104 store-bought fish/shellfish meals in the past year. Compared to the general U.S. adult population, licensed anglers had higher blood lead and mercury levels; and Burmese refuges had higher blood cadmium, lead, and mercury, and higher serum DDE levels. Eating more locally caught fish was associated with higher blood lead, blood mercury, and serum ∑PCBs concentrations among licensed anglers. Licensed anglers and Burmese refugees who reported fish/shellfish consumption in the past week had elevated blood mercury levels compared with those who reported no consumption. Among licensed anglers, eating more store-bought fish meals was also associated with higher blood mercury levels. As part of the program, NYSDOH staff provided fish advisory outreach and education to all participants on ways to reduce their exposures, make healthier choices of fish to eat, and waters to fish from. Overall, our findings on exposure levels and fish consumption provide information to support the development and implementation of exposure reduction public health actions.

The Frequency and Amount of Fish Intake Are Correlated with the White Blood Cell Count and Aerobic Exercise Habit: A Cross-sectional Study

Objective We investigated the relationship between the amount and frequency of fish intake, and the white blood cell (WBC) count and aerobic exercise habits. Methods We conducted a cross-sectional study between April 2019 and March 2020 at the Health Planning Center of Nihon University Hospital on a cohort of 8,981 male subjects. Results The average amount and frequency of fish intake were 134±85 g/week and 2.14±1.28 days/week, respectively. The WBC count decreased significantly as the amount of fish intake increased (p<0.0001). According to a multivariate regression analysis, a high fish intake amount (β=-0.082, p<0.0001) and regular aerobic exercise (β=-0.083, p<0.0001) were independent determinants of a low WBC count. The proportion of subjects engaged in regular aerobic exercise increased with an increase in the amount of fish intake (p<0.0001). Furthermore, the amount and frequency of fish intake significantly correlated with the amount of n-3 polyunsaturated fatty acid intake determined using the Japan's National Nutrition Survey results (both r=0.962 and 0.958). Therefore, the amount of fish intake could be substituted by the average number of days of fish intake per week. Conclusion A high fish intake was an independent determinant of a low WBC count and engagement in regular aerobic exercise, regardless of whether the fish intake was defined by the amount or frequency of fish intake. However, since fish intake frequency can be measured more easily, this may be used to measure the fish intake.

PUFA, genotypes and risk for cardiovascular disease

Polyunsaturated fatty acids (PUFAs) are long chain fatty acids that are characterized by the presence of more than one double bond. These include fatty acids such as ꞷ-3-α-linolenic acid (ALA) and ꞷ-6 -linoleic acid (LA) which can only be obtained from dietary sources and are therefore termed essential fatty acids. They contain the building blocks for dihomo-γ-linolenic acid and arachidonic acid in the ꞷ-6 family as well as eicosapentaenoic acid and docosahexaenoic acid in the ꞷ-3 family. Both ALA and LA are important constituents of animal and plant cell membranes and are important components of anti-inflammatory and pro-inflammatory hormones and therefore, often modulate cellular immunity under chronic inflammatory states. The variation in physiological PUFA levels is under significant genetic influence, the fatty acid desaturase (FADS) genes being key regulators of PUFA metabolism. These genetic variants have been shown to alter fatty acid metabolism and influence the onset and progression of various metabolic conditions. This detailed review discusses the role of PUFAs, diet and genotypes in risk for cardiovascular diseases.

Iodine Content of Wild and Farmed Seafood and Its Estimated Contribution to UK Dietary Iodine Intake

Iodine is an important nutrient for human health and development, with seafood widely acknowledged as a rich source. Demand from the increasing global population has resulted in the availability of a wider range of wild and farmed seafood. Increased aquaculture production, however, has resulted in changes to feed ingredients that affect the nutritional quality of the final product. The present study assessed the iodine contents of wild and farmed seafood available to UK consumers and evaluated its contribution to current dietary iodine intake. Ninety-five seafood types, encompassing marine and freshwater fish and shellfish, of wild and farmed origins, were purchased from UK retailers and analysed. Iodine contents ranged from 427.4 ± 316.1 to 3.0 ± 1.6 µg·100 g-1 flesh wet weight (mean ± SD) in haddock (Melanogrammus aeglefinus) and common carp (Cyprinus carpio), respectively, being in the order shellfish > marine fish > freshwater fish, with crustaceans, whitefish (Gadiformes) and bivalves contributing the greatest levels. Overall, wild fish tended to exhibit higher iodine concentrations than farmed fish, with the exception of non-fed aquaculture species (bivalves). However, no significant differences were observed between wild and farmed Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), and turbot (Psetta maxima). In contrast, farmed European seabass (Dicentrarchus labrax) and seabream (Sparus aurata) presented lower, and Atlantic halibut (Hippoglossus hippoglossus) higher, iodine levels than their wild counterparts, most likely due to the type and inclusion level of feed ingredients used. By following UK dietary guidelines for fish consumption, a portion of the highest oily (Atlantic mackerel, Scomber scombrus) and lean (haddock) fish species would provide two-thirds of the weekly recommended iodine intake (980 µg). In contrast, actual iodine intake from seafood consumption is estimated at only 9.4-18.0% of the UK reference nutrient intake (140 µg·day-1) across different age groups and genders, with females obtaining less than their male equivalents.

Consumption of pistachio nuts positively affects lipid profiles: A systematic review and meta-analysis of randomized controlled trials

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effects of consuming pistachio nuts on lipid profiles (total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], and triglyceride [TG]). Databases of PubMed, Scopus, ISI Web of Science, and Cochrane Library were searched from inception to June 2019 to identify RCTs documenting the effects of consuming pistachio nuts on blood lipid profiles in adults. Effect sizes were reported as weighted mean difference (WMD) and 95% confidence interval (CI) using the random-effects models (DerSimonian-Laird method). Twelve eligible RCTs were included. Consumption of pistachio nuts decreased TC (WMD: -7.48 mg/dL; 95% CI, -12.62 to -2.34), LDL-C (WMD: -3.82 mg/dL; 95% CI, -5.49 to -2.16) and TG (WMD: -11.19 mg/dL; 95% CI, -14.21 to -8.17) levels. However, HDL-cholesterol levels (WMD: 2.45 mg/dL; 95% CI, -2.44 to 7.33) did not change following pistachio consumption. Consuming pistachio nuts may improve lipid profiles (TC, LDL-C, TG) in adults and may be protective against cardiometabolic diseases. However, further studies with larger sample sizes are required to confirm these results.

Dietary and Circulating Long-Chain Omega-3 Polyunsaturated Fatty Acids and Mortality Risk After Myocardial Infarction: A Long-Term Follow-Up of the Alpha Omega Cohort

Background Habitual intake of long-chain omega-3 fatty acids, especially eicosapentaenoic and docosahexaenoic acid (EPA+DHA) from fish, has been associated with a lower risk of fatal coronary heart disease (CHD) in population-based studies. Whether that is also the case for patients with CHD is not yet clear. We studied the associations of dietary and circulating EPA+DHA and alpha-linolenic acid, a plant-derived omega-3 fatty acids, with long-term mortality risk after myocardial infarction. Methods and Results We analyzed data from 4067 Dutch patients with prior myocardial infarction aged 60 to 80 years (79% men, 86% on statins) enrolled in the Alpha Omega Cohort from 2002 to 2006 (baseline) and followed through 2018. Baseline intake of fish and omega-3 fatty acids were assessed through a validated 203-item food frequency questionnaire and circulating omega-3 fatty acids were assessed in plasma cholesteryl esters. Hazard ratios (HRs) with 95% CIs were obtained from Cox regression analyses. During a median follow-up period of 12 years, 1877 deaths occurred, of which 515 were from CHD and 834 from cardiovascular diseases. Dietary intake of EPA+DHA was significantly inversely associated with only CHD mortality (HR, 0.69 [0.52-0.90] for >200 versus ≤50 mg/d; HR, 0.92 [0.86-0.98] per 100 mg/d). Similar results were obtained for fish consumption (HR_CHD, 0.74 [0.53-1.03] for >40 versus ≤5 g/d; P_trend: 0.031). Circulating EPA+DHA was inversely associated with CHD mortality (HR, 0.71 [0.53-0.94] for >2.52% versus ≤1.29%; 0.85 [0.77-0.95] per 1-SD) and also with cardiovascular diseases and all-cause mortality. Dietary and circulating alpha-linolenic acid were not significantly associated with mortality end points. Conclusions In a cohort of Dutch patients with prior myocardial infarction, higher dietary and circulating EPA+DHA and fish intake were consistently associated with a lower CHD mortality risk. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03192410.

2021 Dietary Guidance to Improve Cardiovascular Health: A Scientific Statement From the American Heart Association

Poor diet quality is strongly associated with elevated risk of cardiovascular disease morbidity and mortality. This scientific statement emphasizes the importance of dietary patterns beyond individual foods or nutrients, underscores the critical role of nutrition early in life, presents elements of heart-healthy dietary patterns, and highlights structural challenges that impede adherence to heart-healthy dietary patterns. Evidence-based dietary pattern guidance to promote cardiometabolic health includes the following: (1) adjust energy intake and expenditure to achieve and maintain a healthy body weight; (2) eat plenty and a variety of fruits and vegetables; (3) choose whole grain foods and products; (4) choose healthy sources of protein (mostly plants; regular intake of fish and seafood; low-fat or fat-free dairy products; and if meat or poultry is desired, choose lean cuts and unprocessed forms); (5) use liquid plant oils rather than tropical oils and partially hydrogenated fats; (6) choose minimally processed foods instead of ultra-processed foods; (7) minimize the intake of beverages and foods with added sugars; (8) choose and prepare foods with little or no salt; (9) if you do not drink alcohol, do not start; if you choose to drink alcohol, limit intake; and (10) adhere to this guidance regardless of where food is prepared or consumed. Challenges that impede adherence to heart-healthy dietary patterns include targeted marketing of unhealthy foods, neighborhood segregation, food and nutrition insecurity, and structural racism. Creating an environment that facilitates, rather than impedes, adherence to heart-healthy dietary patterns among all individuals is a public health imperative.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Whole-Grain Diet Increases Whole-Body Protein Balance Compared with a Macronutrient-Matched Refined-Grain Diet

BACKGROUND

There are limited data from randomized control trials to support or refute the contention that whole-grains can enhance protein metabolism in humans.

OBJECTIVES

To examine: 1) the clinical effects of a whole-grain diet on whole-body protein turnover; 2) the cellular effects of whole-grains on protein synthesis in skeletal muscle cells; and 3) the population effects of whole-grain intake on age-related muscle loss.

METHODS

Adults with overweight/obesity (n = 14; age = 40 ± 7 y; BMI = 33 ± 5 kg/m2) were recruited into a crossover, randomized controlled trial (NCT01411540) in which isocaloric, macronutrient-matched whole-grain and refined-grain diets were fully provisioned for two 8-wk periods. Diets differed only in the presence of whole-grains (50 g/1000 kcal). Whole-body protein kinetics were assessed at baseline and after each diet in the fasted-state (13C-leucine) and integrated over 24 h (15N-glycine). In vitro studies using C2C12 cells assessed global protein synthesis by surface sensing of translation and anabolic signaling by Western blot. Complementary epidemiological assessments using the NHANES database assessed the effect of whole-grain intake on muscle function assessed by gait speed in older adults (n = 2783).

RESULTS

Integrated 24-h net protein balance was 3-fold higher on a whole-grain diet compared with a refined-grain diet (P = 0.04). A whole-grain wheat extract increased submaximal rates of global protein synthesis (27%, P < 0.05) in vitro. In a large sample of older adults, whole-grain intake was associated with greater muscle function (OR = 0.92; 95% CI: 0.86, 0.98).

CONCLUSIONS

Consuming 50 g/1000 kcal whole-grains per day promotes greater protein turnover and enhances net protein balance in adults. Whole-grains impact skeletal muscle at the cellular level, and are associated with greater muscle function in older adults. Collectively, these data point to a new mechanism whereby whole-grain consumption favorably enhances protein turnover and improves health outcomes.This clinical trial is registered on clinicaltrials.gov (identifier: NCT01411540).

Dietary ω-3 polyunsaturated fatty acids are protective for myopia

Myopia is a leading cause of visual impairment and blindness worldwide. However, a safe and accessible approach for myopia control and prevention is currently unavailable. Here, we investigated the therapeutic effect of dietary supplements of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) on myopia progression in animal models and on decreases in choroidal blood perfusion (ChBP) caused by near work, a risk factor for myopia in young adults. We demonstrated that daily gavage of ω-3 PUFAs (300 mg docosahexaenoic acid [DHA] plus 60 mg eicosapentaenoic acid [EPA]) significantly attenuated the development of form deprivation myopia in guinea pigs and mice, as well as of lens-induced myopia in guinea pigs. Peribulbar injections of DHA also inhibited myopia progression in form-deprived guinea pigs. The suppression of myopia in guinea pigs was accompanied by inhibition of the "ChBP reduction-scleral hypoxia cascade." Additionally, treatment with DHA or EPA antagonized hypoxia-induced myofibroblast transdifferentiation in cultured human scleral fibroblasts. In human subjects, oral administration of ω-3 PUFAs partially alleviated the near-work-induced decreases in ChBP. Therefore, evidence from these animal and human studies suggests ω-3 PUFAs are potential and readily available candidates for myopia control.

From pond to table: Differences in breeding and consumption affect the balance between dietary risk of residual cadmium and uptake benefits of nutrients in Chinese mitten crab (Eriocheir sinensis)

We used a risk-benefit model to evaluate the effects of different farming methods and consumption habits on dietary risk of Chinese mitten crab. In this study, we found that cadmium levels in the total edible parts and brown meat were 0.029-0.462 mg/kg and 0.017-1.694 mg/kg, respectively. Cadmium exposure experiment showed that brown meat was the main enrichment site of cadmium. Fatty acid test found that the EPA + DHA content in total edible parts fed with formulated feed and iced trash fish was 19.64 ± 3.62 mg/g and 28.72 ± 2.30 mg/g (p > 0.05), respectively, and that in brown meat was 27.66 ± 5.16 mg/g and 40.15 ± 3.50 mg/g (p > 0.05), respectively. According to the risk-benefit model analysis, the dietary risk of brown meat under the two breeding methods is relatively high, but the risk quotient is less than 1.

Intake of marine n-3 polyunsaturated fatty acids and the risk of rheumatoid arthritis: protocol for a cohort study using data from the Danish Diet, Cancer and Health cohort and Danish health registers

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory joint disease with multifactorial aetiology. Smoking is a well-established lifestyle risk factor, but diet may also have an impact on the risk of RA. Intake of the major marine n-3 polyunsaturated fatty acids in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been hypothesised to lower the risk of RA due to their anti-inflammatory effects, although based on limited knowledge. Therefore, we aim to investigate the associations between dietary intake of EPA and DHA and the risk of incident RA.

METHODS AND ANALYSIS

A cohort study. The follow-up design will be based on data from the Danish Diet, Cancer and Health cohort, which was established between 1993 and 1997. The participants will be followed through record linkage using nationwide registers including the Danish Civil Registration System, the Danish National Patient Registry and the Danish National Prescription Registry using the unique Civil Personal Registration number. Time-to-event analyses will be conducted with RA as the outcome of interest. The participants will be followed from inclusion until date of RA diagnosis, death, emigration or end of follow-up. HRs with 95% CIs obtained using Cox proportional hazard regression models, with age as underlying time scale and adjustment for established and potential risk factors, will be used as measures of association.

ETHICS AND DISSEMINATION

The study has been approved by the Data Protection Committee of Northern Jutland, Denmark (2019-87) and the North Denmark Region Committee on Health Research Ethics (N-20190031). Study results will be disseminated through peer-reviewed journals and presentations at international conferences.

Aquatic foods to nourish nations

Despite contributing to healthy diets for billions of people, aquatic foods are often undervalued as a nutritional solution because their diversity is often reduced to the protein and energy value of a single food type ('seafood' or 'fish')1-4. Here we create a cohesive model that unites terrestrial foods with nearly 3,000 taxa of aquatic foods to understand the future impact of aquatic foods on human nutrition. We project two plausible futures to 2030: a baseline scenario with moderate growth in aquatic animal-source food (AASF) production, and a high-production scenario with a 15-million-tonne increased supply of AASFs over the business-as-usual scenario in 2030, driven largely by investment and innovation in aquaculture production. By comparing changes in AASF consumption between the scenarios, we elucidate geographic and demographic vulnerabilities and estimate health impacts from diet-related causes. Globally, we find that a high-production scenario will decrease AASF prices by 26% and increase their consumption, thereby reducing the consumption of red and processed meats that can lead to diet-related non-communicable diseases5,6 while also preventing approximately 166 million cases of inadequate micronutrient intake. This finding provides a broad evidentiary basis for policy makers and development stakeholders to capitalize on the potential of aquatic foods to reduce food and nutrition insecurity and tackle malnutrition in all its forms.

Association between fish oil supplementation and cancer risk according to fatty fish consumption: A large prospective population-based cohort study using UK Biobank

Whether regular fish oil supplementation is associated with cancer risk is controversial. We aimed to evaluate the association of fish oil supplementation on cancer risk according to fatty fish consumption patterns. From the UK Biobank cohort, 470 804 participants with fish oil supplementation data were included. A total of 147 316 individuals with fish oil supplementation were in the exposed group; the other 323 488 were in the unexposed group. No association was found between self-report regular fish oil supplementation and overall cancer risk (hazard ratio [HR] = 0.97, 95% confidence intervals [CIs] = 0.95-1). Stratified by fatty fish consumption level, we found the association between fish oil supplementation and lower cancer risk in participants who consumed fatty fish less than two times per week, with association noted for both overall cancer (HR = 0.96, 95% CI = 0.94-0.99) and some specific cancers (colon cancer: HR = 0.84, 95% CI = 0.75-0.94; hepatobiliary cancer: HR = 0.74, 95% CI = 0.58-0.96; lung cancer: HR = 0.87, 95% CI = 0.78-0.98). On the contrary, a higher risk of breast cancer was observed (HR = 1.16, 95% CI = 1.01-1.32) in participants who consumed fatty fish at least two times per week. In conclusion, our findings underscore the need to refine recommendations for nutritional supplements according to inherent diet habits.

Excess ischemic tachyarrhythmias trigger protection against myocardial infarction in hypertensive rats

Increased level of C-reactive protein (CRP) is a risk factor for cardiovascular diseases, including myocardial infarction and hypertension. Here, we analyzed the effects of CRP overexpression on cardiac susceptibility to ischemia/reperfusion (I/R) injury in adult spontaneously hypertensive rats (SHR) expressing human CRP transgene (SHR-CRP). Using an in vivo model of coronary artery occlusion, we found that transgenic expression of CRP predisposed SHR-CRP to repeated and prolonged ventricular tachyarrhythmias. Excessive ischemic arrhythmias in SHR-CRP led to a significant reduction in infarct size (IS) compared with SHR. The proarrhythmic phenotype in SHR-CRP was associated with altered heart and plasma eicosanoids, myocardial composition of fatty acids (FAs) in phospholipids, and autonomic nervous system imbalance before ischemia. To explain unexpected IS-limiting effect in SHR-CRP, we performed metabolomic analysis of plasma before and after ischemia. We also determined cardiac ischemic tolerance in hearts subjected to remote ischemic perconditioning (RIPer) and in hearts ex vivo. Acute ischemia in SHR-CRP markedly increased plasma levels of multiple potent cardioprotective molecules that could reduce IS at reperfusion. RIPer provided IS-limiting effect in SHR that was comparable with myocardial infarction observed in naïve SHR-CRP. In hearts ex vivo, IS did not differ between the strains, suggesting that extra-cardiac factors play a crucial role in protection. Our study shows that transgenic expression of human CRP predisposes SHR-CRP to excess ischemic ventricular tachyarrhythmias associated with a drop of pump function that triggers myocardial salvage against lethal I/R injury likely mediated by protective substances released to blood from hypoxic organs and tissue at reperfusion.

Fish Oil for Healthy Aging: Potential Application to Master Athletes

Master athletes perform high volumes of exercise training yet display lower levels of physical functioning and exercise performance when compared with younger athletes. Several reports in the clinical literature show that long chain n-3 polyunsaturated fatty acid (LC n-3 PUFA) ingestion promotes skeletal muscle anabolism and strength in untrained older persons. There is also evidence that LC n-3 PUFA ingestion improves indices of muscle recovery following damaging exercise in younger persons. These findings suggest that LC n-3 PUFA intake could have an ergogenic effect in master athletes. However, the beneficial effect of LC n-3 PUFA intake on skeletal muscle in response to exercise training in both older and younger persons is inconsistent and, in some cases, generated from low-quality studies or those with a high risk of bias. Other factors such as the choice of placebo and health status of participants also confound interpretation of existing reports. As such, when considered on balance, the available evidence does not indicate that ingestion of LC n-3 PUFAs above current population recommendations (250–500 mg/day; 2 portions of oily fish per week) enhances exercise performance or recovery from exercise training in master athletes. Further work is now needed related to how the dose, duration, and co-ingestion of LC n-3 PUFAs with other nutrients such as amino acids impact the adaptive response to exercise training. This work should also consider how LC n-3 PUFA supplementation may differentially alter the lipid profile of cellular membranes of key regulatory sites such as the sarcolemma, mitochondria, and sarcoplasmic reticulum.

Dietary Lipids and Dyslipidemia in Chronic Kidney Disease

The progression of chronic kidney disease (CKD) leads to altered lipid metabolism. CKD patients exhibit high blood triglyceride (TG) levels, reduced concentrations and functionality of high-density lipoproteins (HDL), and elevated levels of atherogenic small, dense, low-density lipoproteins (sdLDL). Disorders of lipid metabolism and other metabolic disturbances place CKD patients at high risk for cardiovascular disease (CVD). Extensive evidence supports the cardioprotective effects of unsaturated fatty acids, including their beneficial effect on serum cholesterol and TG levels. Dietary lipids might therefore be especially important in the nutritional management of CKD. We review current dietary recommendations for fat intake by CKD patients and suggest potential nutritional interventions by emphasizing dietary lipids that might improve the blood lipid profile and reduce cardiovascular risk in CKD.

Dietary patterns and cardiometabolic diseases in 0.5 million Chinese adults: a 10-year cohort study

BACKGROUND

The effect of the overall diet quality on cardiometabolic diseases has been well studied in the Western population. However, evidence is still in need regarding dietary patterns depicting unique Chinese dietary habits and their associations with cardiometabolic diseases.

METHODS

A prospective cohort recruited around 0.5 million Chinese residents aged 30-79 years from 10 diverse survey sites during 2004-08. Dietary patterns were obtained using factor analysis based on the habitual consumption of 12 food groups collected at baseline. Among 477,465 eligible participants free of prior heart disease, stroke and cancer, linkages to multiple registries and health insurance database recorded 137,715 cardiovascular diseases (CVD) and 17,412 diabetes cases (among 451,846 non-diabetic participants) until 31 December 2017. Adjusted hazard ratios (HRs) were estimated to compare the risks of cardiometabolic diseases across quintiles of dietary pattern scores using the Cox regression.

RESULTS

Two dietary patterns were derived: the traditional northern pattern, characterised by wheat, other staples, egg and dairy products; and the modern pattern, featured with fresh fruit, meat, poultry, fish, dairy products and soybean. Adherence to either dietary pattern was associated with lower risks of major cardiometabolic diseases in a dose-response relationship way. After multivariate adjustment, participants adhering to the traditional northern pattern the most had an 8% (95%CI: 5-11%) lower risk of CVD in comparison with those adhering the least. Corresponding risk reductions were 12% (11-32%) for haemorrhagic stroke (HS), 14% (8-19%) for ischaemic stroke (IS), and 15% (6-24%) for diabetes, respectively. When comparing extreme quintiles of the modern pattern, the adjusted HR of HS was 0.67 (95%CI: 0.59-0.77). Corresponding HRs were 0.89 (0.86-0.92) for CVD, 0.88 (0.77-0.99) for MCE, 0.85 (0.80-0.89) for IS, and 0.89 (0.81, 0.97) for diabetes.

CONCLUSION

Among Chinese adults, both traditional northern and modern dietary patterns were associated with lower risks of cardiovascular disease and diabetes beyond other risk factors.

Blue poo: impact of gut transit time on the gut microbiome using a novel marker

BACKGROUND AND AIMS

Gut transit time is a key modulator of host-microbiome interactions, yet this is often overlooked, partly because reliable methods are typically expensive or burdensome. The aim of this single-arm, single-blinded intervention study is to assess (1) the relationship between gut transit time and the human gut microbiome, and (2) the utility of the 'blue dye' method as an inexpensive and scalable technique to measure transit time.

METHODS

We assessed interactions between the taxonomic and functional potential profiles of the gut microbiome (profiled via shotgun metagenomic sequencing), gut transit time (measured via the blue dye method), cardiometabolic health and diet in 863 healthy individuals from the PREDICT 1 study.

RESULTS

We found that gut microbiome taxonomic composition can accurately discriminate between gut transit time classes (0.82 area under the receiver operating characteristic curve) and longer gut transit time is linked with specific microbial species such as Akkermansia muciniphila, Bacteroides spp and Alistipes spp (false discovery rate-adjusted p values <0.01). The blue dye measure of gut transit time had the strongest association with the gut microbiome over typical transit time proxies such as stool consistency and frequency.

CONCLUSIONS

Gut transit time, measured via the blue dye method, is a more informative marker of gut microbiome function than traditional measures of stool consistency and frequency. The blue dye method can be applied in large-scale epidemiological studies to advance diet-microbiome-health research. Clinical trial registry website https://clinicaltrials.gov/ct2/show/NCT03479866 and trial number NCT03479866.

The concentration of potentially hazardous elements (PHEs) in the muscle of blue crabs (Callinectes sapidus) and associated health risk

In this study, the concentration of potentially hazardous elements (PHEs) in the muscle of Blue crabs (Callinectes sapidus) from the Strait of Hormuz was analyzed and following the health risk in the consumers by uncertainty and sensitivity analysis in the Monte Carlo simulation (MCS) technique was estimated. Fifty-eight blue card samples (male blue crabs = 33 samples; female blue crabs = 25 samples) were collected in the Strait of Hormuz from May to September 2020 for analysis of Nickel (Ni), Lead (Pb), Cadmium (Cd), and Iron (Fe) using Flame Absorption Spectrometer (FAAS). The order of PHEs in the in muscle male blue crabs was Fe (414.37 ± 288.07 μg/kg.ww) > Pb (238.78 ± 87.83 μg/kg.ww) > Ni (92.57 ± 39.72 μg/kg.ww) > Cd (52.73 ± 18.39 μg/kg.ww) and in female blue crabs Fe (461.16 ± 320.56 μg/kg.ww) > Pb (230.79 ± 125.59 μg/kg.ww) > Ni (84.13 ± 46.07 μg/kg.ww) > Cd (67.412 ± 43.93 μg/kg.ww). The concentration of PHEs muscle of male blue crabs and female blue crabs was not significantly different (P-value > 0.05). Uncertainty of non-carcinogenic risk revealed that P95% of total target hazard quotient (TTHQ) in the adult and children consumers due to ingestion male blue crabs was 5.30E-3 and 1.08E-3, respectively, and P95% of TTHQ in the adult and children due to ingestion female blue crabs was 7.05E-3 and 1.20E-3, respectively. P95% of TTHQ in both adult and children consumers was lower than one value. Therefore, consumers are at the acceptable range of the non-carcinogenic risk due to ingestion muscle of male and female blue crabs in Bandar Abbas. Although the non-carcinogenic risk of blue crab was in the safe range, due to the increase in its consumption and the increase of pollution sources in the Persian Gulf, it is recommended to monitor PHEs in Blue's muscle crabs.

Analyses and Declarations of Omega-3 Fatty Acids in Canned Seafood May Help to Quantify Their Dietary Intake

The American Heart Association (AHA) recently confirmed common recommendations of one to two fish dishes per week in order to prevent cardiovascular disease (CVD). Nevertheless, the natural fluctuations of lipids and fatty acids (FA) in processed seafood caught little public attention. Moreover, consumers of unprocessed seafood in general do not know how much omega-3 fatty acids (omega-3 FA) within servings they actually ingest. The few studies published until today considering this aspect have been re-evaluated in today's context. They included four observational studies with canned fatty coldwater fish (mackerel and herring from the same region, season, producer and research group). Their outcomes were similar to those conducted in the following years using supplements. Cans containing seafood (especially fatty coldwater fish) with declared content of omega-3 FA are ready-to-use products. Human studies have shown a higher bioavailability of omega-3 FA by joint uptake of fat. Canned fatty coldwater fish contain omega-3 FA plus plenty of fat in one and the same foodstuff. That suggests a new dietary paradigm with mixed concepts including several sources with declared content of omega-3 FA for reducing the cardiovascular risk and other acknowledged indications.

PUFA Supplementation and Heart Failure: Effects on Fibrosis and Cardiac Remodeling

Heart failure (HF) characterized by cardiac remodeling is a condition in which inflammation and fibrosis play a key role. Dietary supplementation with n-3 polyunsaturated fatty acids (PUFAs) seems to produce good results. In fact, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have anti-inflammatory and antioxidant properties and different cardioprotective mechanisms. In particular, following their interaction with the nuclear factor erythropoietin 2 related factor 2 (NRF2), the free fatty acid receptor 4 (Ffar4) receptor, or the G-protein coupled receptor 120 (GPR120) fibroblast receptors, they inhibit cardiac fibrosis and protect the heart from HF onset. Furthermore, n-3 PUFAs increase the left ventricular ejection fraction (LVEF), reduce global longitudinal deformation, E/e ratio (early ventricular filling and early mitral annulus velocity), soluble interleukin-1 receptor-like 1 (sST2) and high-sensitive C Reactive protein (hsCRP) levels, and increase flow-mediated dilation. Moreover, lower levels of brain natriuretic peptide (BNP) and serum norepinephrine (sNE) are reported and have a positive effect on cardiac hemodynamics. In addition, they reduce cardiac remodeling and inflammation by protecting patients from HF onset after myocardial infarction (MI). The positive effects of PUFA supplementation are associated with treatment duration and a daily dosage of 1–2 g. Therefore, both the European Society of Cardiology (ESC) and the American College of Cardiology/American Heart Association (ACC/AHA) define dietary supplementation with n-3 PUFAs as an effective therapy for reducing the risk of hospitalization and death in HF patients. In this review, we seek to highlight the most recent studies related to the effect of PUFA supplementation in HF. For that purpose, a PubMed literature survey was conducted with a focus on various in vitro and in vivo studies and clinical trials from 2015 to 2021.

Lipoproteins and fatty acids in chronic kidney disease: molecular and metabolic alterations

Chronic kidney disease (CKD) induces modifications in lipid and lipoprotein metabolism and homeostasis. These modifications can promote, modulate and/or accelerate CKD and secondary cardiovascular disease (CVD). Lipid and lipoprotein abnormalities - involving triglyceride-rich lipoproteins, LDL and/or HDL - not only involve changes in concentration but also changes in molecular structure, including protein composition, incorporation of small molecules and post-translational modifications. These alterations modify the function of lipoproteins and can trigger pro-inflammatory and pro-atherogenic processes, as well as oxidative stress. Serum fatty acid levels are also often altered in patients with CKD and lead to changes in fatty acid metabolism - a key process in intracellular energy production - that induce mitochondrial dysfunction and cellular damage. These fatty acid changes might not only have a negative impact on the heart, but also contribute to the progression of kidney damage. The presence of these lipoprotein alterations within a biological environment characterized by increased inflammation and oxidative stress, as well as the competing risk of non-atherosclerotic cardiovascular death as kidney function declines, has important therapeutic implications. Additional research is needed to clarify the pathophysiological link between lipid and lipoprotein modifications, and kidney dysfunction, as well as the genesis and/or progression of CVD in patients with kidney disease.

Aggregation-induced emission luminogens for lipid droplet imaging

Lipid droplets (LDs) are evolutionarily conserved organelles involved in energy homeostasis and versatile intracellular processes in different cell types. Their importance is ubiquitous, ranges from utilization as the biofunctional components to third-generation biofuel production from microalgae, while morphology and functional perturbations could also relate to the multiple diseases in higher mammals. Biosynthesis of lipids can be triggered by multiple factors related to organismal physiology and the surrounding environment. An early prediction of this might help take necessary actions toward desired outcomes. In vivo visualization of LDs can give molecular insight into regulatory mechanisms and the underlying connections with other cellular structures. Traditional bioprobes for LDs detection often suffer from different dye-specific limitations such as aggregation-caused quenching and self-decomposition phenomena that hinder the research advancement. The emergence of lipid-specific nanoprobes with aggregation-induced emission (AIE) attributes in recent years is promising in remunerative characteristics with defined bioimaging properties. By utilizing the easy synthetic techniques and exploiting the unique physical features of these molecules, highly selective, stable, biocompatible and facile fluorescent probes could be fabricated for lipid detection. This chapter will provide up-to-date insight into the recent advances in lipid-specific AIE-based probes to enhance the opportunities for basic research related to the distinct roles of LDs in living organisms.

Encapsulation and Protection of Omega-3-Rich Fish Oils Using Food-Grade Delivery Systems

Regular consumption of adequate quantities of lipids rich in omega-3 fatty acids is claimed to provide a broad spectrum of health benefits, such as inhibiting inflammation, cardiovascular diseases, diabetes, arthritis, and ulcerative colitis. Lipids isolated from many marine sources are a rich source of long-chain polyunsaturated fatty acids (PUFAs) in the omega-3 form which are claimed to have particularly high biological activities. Functional food products designed to enhance human health and wellbeing are increasingly being fortified with these omega-3 PUFAs because of their potential nutritional and health benefits. However, food fortification with PUFAs is challenging because of their low water-solubility, their tendency to rapidly oxidize, and their variable bioavailability. These challenges can be addressed using advanced encapsulation technologies, which typically involve incorporating the omega-3 oils into well-designed colloidal particles fabricated from food-grade ingredients, such as liposomes, emulsion droplets, nanostructured lipid carriers, or microgels. These omega-3-enriched colloidal dispersions can be used in a fluid form or they can be converted into a powdered form using spray-drying, which facilitates their handling and storage, as well as prolonging their shelf life. In this review, we provide an overview of marine-based omega-3 fatty acid sources, discuss their health benefits, highlight the challenges involved with their utilization in functional foods, and present the different encapsulation technologies that can be used to improve their performance.

Executive summary: Updates to the dietary treatment of prediabetes and type 2 diabetes mellitus

Adequate lifestyle changes significantly reduce the cardiovascular risk factors associated with prediabetes and type 2 diabetes mellitus. Therefore, healthy eating habits, regular physical activity, abstaining from using tobacco, and good sleep hygiene are recommended for managing these conditions. There is solid evidence that diets that are plant-based; low in saturated fatty acids, cholesterol, and sodium; and high in fiber, potassium, and unsaturated fatty acids are beneficial and reduce the expression of cardiovascular risk factors in these subjects. In view of the foregoing, the Mediterranean diet, the DASH diet, a low-carbohydrate diet, and a vegan-vegetarian diet are of note. Additionally, the relationship between nutrition and these metabolic pathologies is fundamental in targeting efforts to prevent weight gain, reducing excess weight in the case of individuals with overweight or obesity, and personalizing treatment to promote patient empowerment. This document is the executive summary of an updated review that includes the main recommendations for improving dietary nutritional quality in people with prediabetes or type 2 diabetes mellitus. The full review is available on the webpages of the Spanish Society of Arteriosclerosis, the Spanish Diabetes Society, and the Spanish Society of Internal Medicine.

Dietary SFAs and ω-6 Fatty Acids Alter Incorporation of ω-3 Fatty Acids into Milk Fat of Lactating CD-1 Mice and Tissues of Offspring

BACKGROUND

Methods to increase the amount of omega-3 (n-3) PUFAs in milk are desirable for neonatal health. The n-3 PUFA, α-linolenic acid (18:3n-3), can be elongated to EPA (20:5n-3) and DHA (22:6n-3). n-6 PUFAs suppress tissue n-3 PUFA incorporation, but the effect of SFAs is not clear.

OBJECTIVES

In this study, we compared the effects of SFAs and n-6 PUFAs on n-3 PUFA incorporation into milk and tissues of lactating mice and tissues of their offspring.

METHODS

Female CD-1 mice were bred at 8 wk of age. All experimental diets included 3% flaxseed oil and were begun on day 8 of lactation: low-fat diet (LFD); high-SFA diet (SAT), with an additional 12% saturated oil; or high-linoleic-acid diet (HLA), with 12% high-linoleic-acid oil (% kcal, carbohydrates:fat:protein: LFD, 49:24:27; both SAT and HLA, 35:46:19; n = 5/treatment). After 5 d, pup stomach milk clot FA profiles, tissue FA profiles in dams and pups, and mammary and hepatic expression of lipid metabolism genes in dams were analyzed. Data were analyzed by ANOVA with treatment diet as a fixed effect.

RESULTS

Dams in all groups had similar total milk fat concentrations, but both SAT and HLA decreased the concentration of n-3 PUFAs (SAT: -23%; HLA: -31%) compared with LFD, and HLA increased milk n-6 FAs by 347% compared with SAT. SAT pups had n-3 PUFA tissue concentrations similar to LFD, but HLA pups had lower n-3 PUFAs than SAT pups in multiple tissues (liver, -32%; kidney, -29%; heart, -28%; muscle, -18%). Mammary expression of lipid metabolism genes was mostly unchanged, but hepatic expression of elongases and desaturases was decreased with SAT compared with LFD [elongation of very-long-chain fatty acid (Elov)5, -42%; Elov6, -64%; fatty acid desaturase (Fads)1, -33%; Fads2, -44%].

CONCLUSIONS

HLA decreased n-3 PUFA concentrations across multiple pup tissues compared with SAT. This suggests that high dietary n-6 PUFAs suppress n-3 PUFA incorporation in neonates.

Tissue and Circulating Fatty Acids as Biomarkers to Evaluate Long-Term Fat Intake Are Tissue and Sex Dependent in CD-1 Mice

BACKGROUND

There is currently no consensus on which tissues are optimal for assessing specific diet-derived fatty acids (FAs) as biomarkers for long-term dietary studies.

OBJECTIVES

This study measured the content of unique diet-derived FAs from dairy, echium, and fish in tissues (adipose, muscle, liver, erythrocyte membranes, and plasma phospholipids, cholesterol esters, triglycerides, and free fatty acids) after long-term feeding in CD-1 mice.

METHODS

Beginning at weaning, mice (n = 10-11/sex/diet) were fed 1 of 4 diets (40% kcal/total energy) that only differed in FA composition: control fat blend (CON), reflecting the FA profile of the average US American diet, or CON supplemented with 30% of fish oil (FO), dairy fat (DF), or echium oil (EO). After 13 mo, tissues were collected to determine FAs via gas-liquid chromatography. Tissue FAs were analyzed via 2-factor ANOVA, and relationships between FA intake and tissue content were assessed with Spearman correlations.

RESULTS

As anticipated, 20:5n-3 (ω-3) tissue content was ≤32-fold greater in FO- compared with CON-fed mice (P < 0.05). In addition, 20:5n-3 intake strongly correlated with its content in all tissues (ρ = 0.67-0.76; P < 0.05). Echium oil intake also influenced tissue FA content in mice as expected. For example, 18:3n-6 was ≤25-fold greater in adipose, muscle, and liver tissues of EO-fed compared with CON-fed mice (P < 0.05). Tissue content of FAs typically considered biomarkers of dairy fat intake (15:0, 16:1 t9, and 17:0) was often not greater in mice fed DF than other diet groups, although 18:2 c9, t11 content was ≤6-fold greater in tissues from DF-fed compared with CON-fed mice (P < 0.05). The content of dairy-derived FAs in blood fractions of females was up to 2-fold greater compared with males, whereas docosapentaenoic acid content was up to 1-fold greater in all blood fractions and in liver tissue of males compared with females (P < 0.05). In adipose, muscle, and liver tissue, the content of γ-linolenic acid and stearidonic acid was less than 1-fold greater in females than in males (P < 0.05).

CONCLUSIONS

Our study indicates that the distribution of dietary FAs is tissue and sex dependent in aged CD-1 mice. Research using FA biomarkers should assess a combination of FA biomarkers to accurately validate patterns of FA intake and source.

The relationship between dietary intakes and plasma concentrations of PUFA in school-age children from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort

An adequate intake of PUFA plays a vital role in human health. Therefore, it is important to assess PUFA intakes in different populations and validate them with biomarkers, but only a few small studies are in paediatric populations. We calculated the dietary intake of PUFA and their main food sources in children and assessed associations between PUFA intakes and plasma proportions. Dietary intakes of 7-year-old children (n 8242) enrolled in the Avon Longitudinal Study of Parents and Children were calculated from the parental-completed FFQ. Plasma PUFA were measured in 5571 children 8 months later, and 4380 children had complete dietary and plasma data. The association between dietary and plasma PUFA proportions was estimated using Spearman's correlation coefficients, quintile cross-classification and Cohen's κ coefficients. Mean total PUFA intake was 13·2 g/d (sd 4·2), contributing 6·5 % of total energy intake; n-6 PUFA contributed 5·2 % and n-3 PUFA 0·7 %. The n-6:n-3 ratio was 7·9:1. Mean intakes of EPA and DHA were 35·7 mg/d and 49·7 mg/d, respectively. Most n-3 and n-6 PUFA intakes were weakly correlated with their respective plasma lipids (0·07 ≤ r ≤ 0·16, P < 0·001). The correlation between dietary and plasma DHA was stronger though (r = 0·34, P < 0·001), supported by a modest level of agreement between quintiles (k = 0·32). The results indicate that the FFQ was able to reasonably rank the long-chain (LC) PUFA, DHA, in this paediatric population. Public health initiatives need to address the suboptimal ratio of n-6:n-3 PUFA and very low n-3 LC-PUFA intakes in school-age children in the UK.

Cardiac contractile dysfunction, during and following ischaemia, is attenuated by low-dose dietary fish oil in rats

AIMS

Supplementing animal diets with high-dose fish oil, rich in long chain omega-3 (ω-3) docosahexaenoic acid (DHA), enhances cardiac contractile efficiency and attenuates dysfunction, attributable to ischaemia. However, it remains unclear whether smaller doses, equivalent to what is achievable via regular fish consumption in the human diet, offer similar protection.

METHODS

Male Sprague-Dawley (12-15w) rats were fed isoenergetic diets (ad libitum) containing 10% fat by weight (22% energy) for 4-5w. Control diet (CON) contained 5.5% beef tallow; 2.5% ω-6 sunflower seed oil; 2% olive oil. Fish oil diets included high-DHA tuna oil exchanged for olive oil to provide 0.32% (FO1; human equivalent EPA + DHA 570 mg/d) or 1.25% (FO2; equivalent EPA + DHA 2.3 g/d) wt/wt dose of fish oil. Anaesthetised rats (pentobarbital: 60 mg/kg i.p.) were subjected to 45 min coronary artery occlusion then reperfusion in vivo as a whole animal model of regional myocardial ischaemia, with left ventricular haemodynamic function measured by conductance catheter.

RESULTS

Ischaemia-induced reductions in rate pressure product recovered faster in the FO2 group and post-ischaemic left ventricular pressure-volume loop integrity (shifted downwards and right in CON) was partially protected in both fish oil groups.

CONCLUSION

Ischaemia-induced contractile dysfunction in rats is limited from fish oil doses equivalent to regular consumption of fish in the human diet. These observations highlight plausible and clinically relevant physiological changes that rationalise nutritional conditioning of the heart with DHA for on-going cardioprotection.

In vitro intestinal digestion of lipids from the marine diatom Porosira glacialis compared to commercial LC n-3 PUFA products

Marine sources of long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) are in high demand for use in health supplements. Mass cultivated marine microalgae is a promising and sustainable source of LC n-3 PUFA, which relieves pressure on natural fish stocks. The lipid class profile from cultivated photosynthetic algae differ from the marine organisms currently used for the production of LC n-3 PUFA. The objective of this study was to compare in vitro intestinal digestion of oil extracted from the cold-adapted marine diatom Porosira glacialis with commercially available LC n-3 PUFA supplements; cod liver oil, krill oil, ethyl ester concentrate, and oil from the copepod Calanus finmarchicus (Calanus® oil). The changes in the free fatty acids and neutral and polar lipids during the enzymatic hydrolysis were characterized by liquid and gas chromatography. In Calanus® oil and the Ethyl ester concentrate, the free fatty acids increased very little (4.0 and 4.6%, respectively) during digestion. In comparison, free fatty acids in Krill oil and P. glacialis oil increased by 14.7 and 17.0%, respectively. Cod liver oil had the highest increase (28.2%) in free fatty acids during the digestion. Monounsaturated and saturated fatty acids were more easily released than polyunsaturated fatty acids in all five oils.

Nutrition and origin of US chain restaurant seafood

BACKGROUND

Seafood has a nutritional profile that can be beneficial to human health, which gives it a role to play in healthy diets. In addition, because its production and harvesting can have fewer environmental impacts than some forms of animal protein, it can contribute to sustainable diets. However, the positive health and environmental outcomes are not guaranteed-they depend on how seafood is prepared and served and whether it is sourced from sustainable fisheries and aquaculture industries.

OBJECTIVES

We examined the availability and nutritional attributes of seafood meals at chain restaurants in the United States. We assessed nutritional attributes by store type and geography. We also assessed menu labeling for species, production methods, and origin.

METHODS

The study population was 159 chain restaurants with 100,948 branch locations in the United States. Data were harvested from online restaurant menus, and the nutritional profile of seafood meals was calculated.

RESULTS

The average seafood menu item provides up to 49-61% of the total daily limit of saturated fat, 65% of the total daily limit of sodium, and 58-71% of total daily protein requirement for adult men and women. Restaurant chains located in the Deep South and Ohio River Valley, and casual dining chains nationally, carry seafood meals with more total calories and saturated fat per 100 g than other regions or chain types. Most menu items did not list origin or production methods, which is information that would help consumers make informed decisions.

CONCLUSIONS

The added ingredients and cooking methods used at chain restaurants can attenuate the health benefits of seafood. We recommend reformulating menus to reduce portion sizes, total calories, added fat, and sodium content per meal and to improve consumer-facing information about origin and production methods.