Dietary intake of differently fed salmon; the influence on markers of human atherosclerosis

Salmon Food-Specific Compounds and Their Metabolites Increase in Human Plasma and Are Associated with Cardiometabolic Health Indicators Following a Mediterranean-Style Diet Intervention

BACKGROUND

Nutrimetabolomics allows for the comprehensive analysis of foods and human biospecimens to identify biomarkers of intake and begin to probe their associations with health. Salmon contains hundreds of compounds that may provide cardiometabolic benefits.

OBJECTIVES

We used untargeted metabolomics to identify salmon food-specific compounds (FSCs) and their predicted metabolites that were found in plasma after a salmon-containing Mediterranean-style (MED) diet intervention. Associations between changes in salmon FSCs and changes in cardiometabolic health indicators (CHIs) were also explored.

METHODS

For this secondary analysis of a randomized, crossover, controlled feeding trial, 41 participants consumed MED diets with 2 servings of salmon per week for 2 5-wk periods. CHIs were assessed, and fasting plasma was collected pre- and postintervention. Plasma, salmon, and 99 MED foods were analyzed using liquid chromatography-mass spectrometry-based metabolomics. Compounds were characterized as salmon FSCs if detected in all salmon replicates but none of the other foods. Metabolites of salmon FSCs were predicted using machine learning. For salmon FSCs and metabolites found in plasma, linear mixed-effect models were used to assess change from pre- to postintervention and associations with changes in CHIs.

RESULTS

Relative to the other 99 MED foods, there were 508 salmon FSCs with 237 unique metabolites. A total of 143 salmon FSCs and 106 metabolites were detected in plasma. Forty-eight salmon FSCs and 30 metabolites increased after the intervention (false discovery rate <0.05). Increases in 2 annotated salmon FSCs and 2 metabolites were associated with improvements in CHIs, including total cholesterol, low-density lipoprotein cholesterol, triglycerides, and apolipoprotein B.

CONCLUSIONS

A data-driven nutrimetabolomics strategy identified salmon FSCs and their predicted metabolites that were detectable in plasma and changed after consumption of a salmon-containing MED diet. Findings support this approach for the discovery of compounds in foods that may serve, upon further validation, as biomarkers or act as bioactive components influential to health. The trials supporting this work were registered at NCT02573129 (Mediterranean-style diet intervention) and NCT05500976 (ongoing clinical trial).

The effect of omega-3 polyunsaturated fatty acid intake on blood levels of omega-3s in people with chronic atherosclerotic disease: a systematic review

CONTEXT

Atherosclerosis is a systemic pro-inflammatory and pro-oxidative disease, accounting for approximately a third of deaths globally. It has been proposed that omega-3s, through their antioxidant and anti-inflammatory properties, mitigate atherosclerotic disease progression. However, due to the systemic pro-inflammatory and pro-oxidative state of atherosclerosis, it is proposed that patients with atherosclerotic disease may have higher omega-3 requirements than the average requirement, due to increased nutrient utilization in anti-inflammatory and anti-oxidant processes.

OBJECTIVE

The aim of this review was to determine what dose and duration of omega-3 supplementation is required to reach a therapeutic blood level of omega-3s (eicosapentaenoic acid ≥150 µg/mL or omega-3 index ≥8%) in people with chronic atherosclerotic disease.

DATA SOURCES

This systematic review comprehensively searched MEDLINE, Emcare, Scopus, and CINAHL using key search terms for atherosclerotic disease, omega-3, supplementation, and blood levels of omega-3s.

DATA EXTRACTION

Two reviewers independently screened 529 randomized controlled trials (RCTs) supplementing omega-3s in patients with chronic atherosclerotic disease.

DATA ANALYSIS

In total, 25 journal articles from 17 original RCTs were included and assessed quantitatively. Supplementation at 1.8 g to 3.4 g per day for a 3-month-6-month duration, and at 4.4 g and above for as little as 1 month-6 months were identified as the most effective dosage ranges for increasing blood levels of omega-3s to therapeutic levels in people with atherosclerotic disease.

CONCLUSIONS

Consideration should be given to routine omega-3 supplementation and to increasing the omega-3 dietary recommendations and upper limits of daily intake to improve clinical outcomes and reduce the risk of cardiac mortality in this population.

[Nutrition for diabetic patients (Update 2023)]

All patients with diabetes require individual and personalized nutritional consultation with professionals. The patient's needs should be the primary focus of the dietary therapy, taking their lifestyle and the type of diabetes into consideration. With the recommendations to the patient's diet, there need to be specific metabolic goals to reduce the disease's progression and to avoid long term health effects. Therefore, practical guidelines such as portion size and meal planning tips should be the main focus.According to the latest national and international standards, patients suffering from diabetes should have access to nutrition consulting and nutritional training. During consultation they can be supported on- how to manage their health condition and choosing food and beverage to improve their health.These practical recommendations sum up the latest literature on nutritional aspects of diabetes treatment.

Consumption of Farmed Fish, Fed with an Olive-Pomace Enriched Diet, and Its Effect on the Inflammatory, Redox, and Platelet-Activating Factor Enzyme Profile of Apparently Healthy Adults: A Double-Blind Randomized Crossover Trial

A fish-rich diet has a beneficial effect on cardiovascular health. The platelet activating factor (PAF) is involved in the development of atherosclerosis, and in vitro results support the regulating action of bioactive nutrients on PAF metabolism. The purpose of this study is to examine whether the consumption of farmed fish fed with an olive-pomace enriched diet (EF) affects PAF metabolism and the markers of inflammation and oxidative stress compared to the consumption of conventionally fed farmed fish (CF). Thirty apparently healthy adults completed a randomized double-blind crossover trial, during which they consumed both CF and EF twice a week for 8 weeks with a six-week washout period in between. The activities of PAF acetylhydrolase (PAF-AH), lysoPAF acetyltransferase (lysoPAF-AT), DTT-insensitive CDP-choline: 1-alkyl-2-acetyl-sn-glycerol-choline-phosphotransferase (PAF-CPT) in leukocytes, and lipoprotein-associated phospholipase A₂ (LpPLA₂) in serum were determined. The quantities of interleukin-6 (IL-6), high sensitivity C-reactive protein (hsCRP), oxidized LDL (ox-LDL), thiobarbituric acid-reactive substances (TBARS), and glutathione peroxidase (GPx), as well as the serum oxidation, were also determined. Both types of fish exerted similar effects as there were no statistically significant differences between the two interventions except for an elevated PAF-CPT and reduced arachidonic acid (AA) in the red blood cell (RBC) membrane lipids after the EF intake.

Effects of ω-3 Polyunsaturated Fatty Acids on Coronary Atherosclerosis and Inflammation: A Systematic Review and Meta-Analysis

Background and Purpose

Multiple guidelines suggest the ω-3 polyunsaturated fatty acids (ω-3 PUFAs) help to prevent major vascular events of coronary heart disease (CHD), but the data on large trials of ω-3 fatty acids are controversial. We reviewed the available evidence to determine the effect of ω-3 PUFAs on coronary atherosclerosis.

Materials and Methods

Literature were from online databases. Randomized controlled trials (RCTs) or observational studies were acceptable. Quantitative data synthesis was conducted using R version 4.1.2. Each outcome was calculated using standardized mean difference (SMD) in a random-effect model. Sensitivity analysis was conducted for each outcome. A total of 21 RCTs and 1 observational study with 2,277 participants were included.

Results

Meta-analysis indicated a benefit of ω-3 PUFAs on coronary atherosclerosis, namely, (1) ω-3 PUFAs can reduce the atherosclerotic plaque volume (SMD −0.18; 95% CI −0.31 to −0.05); (2) ω-3 PUFAs can help reduce the loss of the diameter of the narrowest segments of coronary arteries in patients with CHD (SMD 0.29; 95% CI, 0.05–0.53); (3) ω-3 PUFAs do not have significant effect on volume of lipid plaque in coronary arteries (SMD −1.18; 95% CI −2.95 to 0.58), volume of fiber plaque (SMD 0.26; 95% CI −0.81 to 1.33), and calcified plaque (SMD 0.17; 95% CI −0.55 to 0.89); and (4) ω-3 PUFAs had no significant effect on endothelial inflammatory factors in peripheral blood.

Conclusions

We confirmed that ω-3 PUFAs benefit patients with CHD by reducing the progression of coronary atherosclerosis. We indicated that the benefits were not caused by reducing endothelial inflammations of coronary arteries.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021285139, identifier: CRD42021285139.

Health-Related Quality-of-Life Trajectories over Time in Older Men and Women with Advanced Chronic Kidney Disease

BACKGROUND AND OBJECTIVES

The effect of sex on longitudinal health-related quality of life remains unknown in CKD. Here we assess differences in the sex-specific evolution of health-related quality of life in older men and women with advanced CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The European Quality Study on Treatment in Advanced Chronic Kidney Disease is a European observational prospective cohort study in referred patients with CKD and an incident eGFR<20 ml/min per 1.73 m² who are ≥65 years of age not on dialysis. Health-related quality of life was measured using the 36-Item Short Form Survey at 3- to 6-month intervals between April 2012 and September 2020, providing Physical Component Summary and Mental Component Summary scores. Trajectories were modeled by sex using linear mixed models, and sex differences in health-related quality-of-life slope were explored.

RESULTS

We included 5345 health-related quality-of-life measurements in 1421 participants. At baseline, women had considerably lower mean Physical Component Summary (42) and Mental Component Summary (60) compared with men (Physical Component Summary: 55; Mental Component Summary: 69; P<0.001). However, during follow-up, Physical Component Summary and Mental Component Summary scores declined approximately twice as fast in men (Physical Component Summary: 2.5 per year; 95% confidence interval, 1.8 to 3.1; Mental Component Summary: 2.7 per year; 95% confidence interval, 2.0 to 3.4) compared with in women (Physical Component Summary: 1.1 per year; 95% confidence interval, 0.1 to 2.0; Mental Component Summary: 1.6 per year; 95% confidence interval, 0.7 to 2.6). This difference was partly attenuated after adjusting for important covariates, notably eGFR decline. Higher serum phosphate, lower hemoglobin, and the presence of preexisting diabetes were associated with lower Physical Component Summary and Mental Component Summary scores in men but to a lesser extent in women.

CONCLUSIONS

Among older men and women with advanced CKD, women had lower health-related quality of life at baseline, but men experienced a more rapid decline in health-related quality of life over time.

Plasma Metabolomic Signatures of Healthy Dietary Patterns in the Chronic Renal Insufficiency Cohort (CRIC) Study

BACKGROUND

In individuals with chronic kidney disease (CKD), healthy dietary patterns are inversely associated with CKD progression. Metabolomics, an approach that measures many small molecules in biofluids, can identify biomarkers of healthy dietary patterns.

OBJECTIVES

We aimed to identify known metabolites associated with greater adherence to 4 healthy dietary patterns in CKD patients.

METHODS

We examined associations between 486 known plasma metabolites and Healthy Eating Index (HEI)-2015, Alternative Healthy Eating Index (AHEI)-2010, the Dietary Approaches to Stop Hypertension (DASH) diet, and alternate Mediterranean diet (aMED) in 1056 participants (aged 21-74 y at baseline) in the Chronic Renal Insufficiency Cohort (CRIC) Study. Usual dietary intake was assessed using a semiquantitative FFQ. We conducted multivariable linear regression models to study associations between healthy dietary patterns and individual plasma metabolites, adjusting for sociodemographic characteristics, health behaviors, and clinical factors. We used principal component analysis to identify groups of metabolites associated with individual food components within healthy dietary patterns.

RESULTS

After Bonferroni correction, we identified 266 statistically significant diet-metabolite associations (HEI: n = 60; AHEI: n = 78; DASH: n = 77; aMED: n = 51); 78 metabolites were associated with >1 dietary pattern. Lipids with a longer acyl chain length and double bonds (unsaturated) were positively associated with all 4 dietary patterns. A metabolite pattern low in saturated diacylglycerols and triacylglycerols, and a pattern high in unsaturated triacylglycerols was positively associated with intake of healthy food components. Plasmalogens were negatively associated with the consumption of nuts and legumes and healthy fat, and positively associated with the intake of red and processed meat.

CONCLUSIONS

We identified many metabolites associated with healthy dietary patterns, indicative of food consumption. If replicated, these metabolites may be considered biomarkers of healthy dietary patterns in patients with CKD.

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

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

The effects of low-ratio n-6/n-3 PUFA on biomarkers of inflammation: a systematic review and meta-analysis

OBJECTIVE

The purpose of the systematic review and meta-analysis was to determine if low-ratio n-6/n-3 long-chain polyunsaturated fatty acid (PUFA) supplementation affects serum inflammation markers based on the current studies.

METHODS

PubMed, Embase and The Cochrane library databases were systematically searched to find randomized controlled trials (RCTs) on the effect of low-ratio n-6/n-3 PUFA intervention on inflammation markers up to July 2020. Data were pooled using standardized mean difference (SMD) and 95% confidence intervals (95% CI), with P value ≦ 0.05 as statistical significance.

RESULTS

Thirty-one RCTs were included in the meta-analysis. The analysis indicated that increasing low-ratio n-6/n-3 PUFA supplementation decreased the level of tumor necrosis factor-α (TNF-α) (SMD = -0.270; 95% CI: -0.433, -0.106; P = 0.001) and interleukin 6 (IL-6) (SMD = -0.153; 95% CI: -0.260, -0.045; P = 0.005). There were no significant effects on C-reactive protein (CRP) (SMD = -0.027; 95% CI: -0.189: 0.135; P = 0.741). Subgroup analysis indicated that there was a significant reduction in TNF-α serum concentration in subjects from Asia (SMD: -0.367; 95% CI: -0.579, -0.155; P = 0.001) and in subjects with diseases (SMD: -0.281; 95% CI: -0.436, -0.127; P < 0.001). In the subgroup of the n-6/n-3 ratio ≦5, low-ratio n-6/n-3 PUFA supplementation could decrease the level of TNF-α (SMD: -0.335; 95% CI: -0.552, -0.119; P = 0.002). Serum IL-6 decreased significantly in patients from the Europe subgroup (SMD: -0.451; 95% CI: -0.688, -0.214; P < 0.001), but not in Asia (SMD: -0.034; 95% CI: -0.226, 0.157; P = 0.724), North America (SMD: -0.115; 95% CI: -0.274, 0.044; P = 0.157) and Oceania (SMD: 0.142; 95% CI: -0.557, 0.842; P = 0.690).

CONCLUSION

Low-ratio n-6/n-3 PUFA supplementation could decrease significantly the concentration of serum TNF-α and IL-6, but not decrease CRP concentration.

The nutritional and cardiovascular health benefits of rapeseed oil-fed farmed salmon in humans are not decreased compared with those of traditionally farmed salmon: a randomized controlled trial

PURPOSE

Farmed fish are increasingly raised on feeds containing vegetable oils, which affects their composition and possibly health properties. We investigated the effects of consuming farmed salmon, raised on different feeding regimes, on nutrient status and health outcomes in healthy subjects.

METHODS

Salmon were grown on feeds containing mainly fish oil (FO) or rapeseed oil (RO), resulting in an eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) content of fillets of 2.1 or 0.9 g/100 g, respectively. In a randomized parallel controlled trial, 51 healthy subjects were allocated to consume 2 portions/week of FO salmon (n = 17), RO salmon (n = 17) or no additional salmon (Control, n = 17) as part of their habitual diet, for 18 weeks. We collected blood at 0, 9 and 18 weeks to measure omega-3 index (O3I) in red blood cells, plasma markers of cardiovascular risk, serum 25(OH)-vitamin D₃ (25(OH)D₃) and plasma trace elements.

RESULTS

After 18 weeks, O3I was similarly increased in subjects consuming 2 portions/week of FO or RO salmon compared to control (both p < 0.05). Serum 25(OH)D₃ was significantly higher, whereas plasma triacylglycerols were significantly lower in subjects consuming RO salmon compared to control (both p < 0.05). Heart rate was significantly lower in subjects consuming FO salmon after 9 weeks, compared to control (p < 0.01). Salmon consumption did not affect other markers.

CONCLUSION

Consuming two portions/week of salmon raised on rapeseed oil rather than fish oil increased the O3I and vitamin D status, and decreased plasma triacylglycerols. These outcomes endorse opportunities for developing more sustainable feeds within aquaculture food systems.

CLINICAL TRIAL REGISTRY

This trial was registered at clinicaltrials.gov as NCT01916434.

Very Long Chain Marine n-3 Polyunsaturated Fatty Acids in Atherothrombotic Heart Disease. A Brief Review, with a Focus on Metabolic Effects

The global burden of atherothrombotic heart disease should be considered as a life-style disorder where differences in dietary habits and related risk factors like limited physical activity and adiposity together play important roles. Related metabolic changes have been scientifically elucidated in recent decades, and the role of the very-long-chain marine fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been much focused on, especially their possible effects on processes like inflammation and thrombosis. In the present brief review of related metabolic mechanisms, the effects of these fatty acids in a clinical setting have been referred to, including some of the authors' work on this topic. The main focus is the divergent results in the field and the important differences between the study population, the type of supplements and fresh marine sources, the proportion of EPA versus DHA dosages, and the duration of supplementation in clinical trials. We conclude that daily intake of at least 1 g of EPA + DHA may improve a dysmetabolic state in the population. The potential to reduce the risk and progression of atherothrombotic heart disease is still a matter of debate.

Recovery of Fatty Acid Composition in Mediterranean Yellowtail (Seriola dumerili, Risso 1810) fed a Fish-Oil Finishing Diet

The present study evaluated the effects of wash-out on the fatty acid (FA) composition in the muscles of Mediterranean yellowtail. After 109 days during which fish were fed either a fish oil (FO)-based diet (FO 100) or a diet (FO 0) in which FO was completely substituted by vegetable oils, all fish were subjected to a wash-out with FO 100 diet for 90 days. The FA profile of muscles in fish fed FO 0 diet at the beginning of the experiment reflected that of dietary vegetable oils, rich in linoleic acid (LA), and α-linolenic acid (ALA), and was deficient in AA (arachidonic acid), EPA (eicosapentaenoic acid), and DHA (docosahexaenoic acid). No essential FA were fully restored in fish previously fed FO 0 diet on 45th or 90th day of wash-out. At the end of wash-out, the FA composition showed that AA, EPA, and DHA in the white muscles increased by +33%, +16%, and +43% (p < 0.001), respectively. Similarly, AA and DHA in the red muscles increased by +33% and +41% respectively, while EPA remained similar to fish fed FO 0 diet exclusively. Therefore, a 90-d wash-out can partially improve the FA profile in muscles of Mediterranean yellowtail previously fed vegetable oil-based diets.

Biomarkers of meat and seafood intake: an extensive literature review

Meat, including fish and shellfish, represents a valuable constituent of most balanced diets. Consumption of different types of meat and fish has been associated with both beneficial and adverse health effects. While white meats and fish are generally associated with positive health outcomes, red and especially processed meats have been associated with colorectal cancer and other diseases. The contribution of these foods to the development or prevention of chronic diseases is still not fully elucidated. One of the main problems is the difficulty in properly evaluating meat intake, as the existing self-reporting tools for dietary assessment may be imprecise and therefore affected by systematic and random errors. Dietary biomarkers measured in biological fluids have been proposed as possible objective measurements of the actual intake of specific foods and as a support for classical assessment methods. Good biomarkers for meat intake should reflect total dietary intake of meat, independent of source or processing and should be able to differentiate meat consumption from that of other protein-rich foods; alternatively, meat intake biomarkers should be specific to each of the different meat sources (e.g., red vs. white; fish, bird, or mammal) and/or cooking methods. In this paper, we present a systematic investigation of the scientific literature while providing a comprehensive overview of the possible biomarker(s) for the intake of different types of meat, including fish and shellfish, and processed and heated meats according to published guidelines for biomarker reviews (BFIrev). The most promising biomarkers are further validated for their usefulness for dietary assessment by published validation criteria.

Erucic Acid (22:1n-9) in Fish Feed, Farmed, and Wild Fish and Seafood Products

The European Food Safety Authority (EFSA) published a risk assessment of erucic acid (22:1n-9) in 2016, establishing a Tolerable Daily Intake (TDI) for humans of 7 mg kg⁻¹ body weight per day. This report largely excluded the contribution of erucic acid from fish and seafood, due to this fatty acid often not being reported separately in seafood. The Institute of Marine Research (IMR) in Norway analyzes erucic acid and has accumulated extensive data from analyses of fish feeds, farmed and wild fish, and seafood products. Our data show that rapeseed oil (low erucic acid varieties) and fish oil are the main sources of erucic acid in feed for farmed fish. Erucic acid content increases with total fat content, both in farmed and wild fish, and it is particularly high in fish liver, fish oil, and oily fish, such as mackerel. We show that the current TDI could be exceeded with a 200 g meal of mackerel, as at the maximum concentration analyzed, such a meal would contribute 143% to the TDI of a 60 kg person. These data cover a current knowledge gap in the scientific literature regarding the content of erucic acid in fish and seafood.

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

Since the 2002 American Heart Association scientific statement "Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease," evidence from observational and experimental studies and from randomized controlled trials continues to emerge to further substantiate the beneficial effects of seafood long-chain n-3 polyunsaturated fatty acids and cardiovascular disease. A recent American Heart Association science advisory addressed the specific effect of n-3 polyunsaturated fatty acid supplementation on clinical cardiovascular events. This American Heart Association science advisory extends that review and offers further support to include n-3 polyunsaturated fatty acids from seafood consumption. Several potential mechanisms have been investigated, including antiarrhythmic, anti-inflammatory, hematologic, and endothelial, although for most, longer-term dietary trials of seafood are warranted to substantiate the benefit of seafood as a replacement for other important sources of macronutrients. The present science advisory reviews this evidence and makes a suggestion in the context of the 2015-2020 Dietary Guidelines for Americans and in consideration of other constituents of seafood and the impact on sustainability. We conclude that 1 to 2 seafood meals per week be included to reduce the risk of congestive heart failure, coronary heart disease, ischemic stroke, and sudden cardiac death, especially when seafood replaces the intake of less healthy foods.

Are we what we eat? Changes to the feed fatty acid composition of farmed salmon and its effects through the food chain

'Are we what we eat?' Yes and no. Although dietary fat affects body fat, there are many modifying mechanisms. In Atlantic salmon, there is a high level of retention of the n-3 fatty acid (FA) docosahexaenoic acid (DHA, 22:6n-3) relative to the dietary content, whereas saturated FAs never seem to increase above a specified level, which is probably an adaptation to low and fluctuating body temperature. Net production of eicosapentaenoic acid (EPA, 20:5n-3) and especially DHA occurs in salmon when dietary levels are low; however, this synthesis is not sufficient to maintain EPA and DHA at similar tissue levels to those of a traditional fish oil-fed farmed salmon. The commercial diets of farmed salmon have changed over the past 15 years towards a more plant-based diet owing to the limited availability of the marine ingredients fish meal and fish oil, resulting in decreased EPA and DHA and increased n-6 FAs. Salmon is part of the human diet, leading to the question 'Are we what the salmon eats?' Dietary intervention studies using salmon have shown positive effects on FA profiles and health biomarkers in humans; however, most of these studies used salmon that were fed high levels of marine ingredients. Only a few human intervention studies and mouse trials have explored the effects of the changing feed composition of farmed salmon. In conclusion, when evaluating feed ingredients for farmed fish, effects throughout the food chain on fish health, fillet composition and human health need to be considered.

Fish oil emulsion supplementation might improve quality of life of diabetic patients due to its antioxidant and anti-inflammatory properties

Diabetes-related complications, including cardiovascular disease, retinopathy, nephropathy, and neuropathy, are a significant cause of increased morbidity and mortality among people with diabetes. Previous studies have confirmed that hyperglycemia has pro-oxidative and proinflammatory properties which cause diabetic complications. We hypothesized that supplementation of fish oil emulsion (FOE), rich in omega-3 polyunsaturated fatty acids, to diabetic patients might reduce hyperglycemia-induced pathological changes due to specific properties of FOE. Omega-3 polyunsaturated fatty acids have a wide range of biological effects. In this project, we have examined the potential protective effect of the FOE on hyperglycemia-induced oxidative stress and cytokine generation in monocytes/macrophages U937 system in vitro. The monocytes/macrophages U937 were cultivated under normal or hyperglycemic (35 mmol/L glucose) conditions with/without FOE for 72 hours. We have focused on specific markers of oxidative stress (antioxidant capacity; superoxide dismutase activity; oxidative damage to DNA, proteins, and lipids) and inflammation (tumor necrosis factor, interleukin-6, interleukin-8, monocytic chemotactic protein-1). Hyperglycemia caused reduction of antioxidant capacity, induction of DNA damage, and proinflammatory cytokine secretion. FOE significantly increased antioxidant capacity of cells as well as superoxide dismutase activity and significantly reduced tumor necrosis factor, interleukin-6, interleukin-8, and monocytic chemotactic protein-1 release. No effect was observed on oxidative damage to DNA, proteins, and lipids. Our results indicate that FOE can reduce hyperglycemia-induced pathological mechanisms by its antioxidant and anti-inflammatory properties.

Lower levels of Persistent Organic Pollutants, metals and the marine omega 3-fatty acid DHA in farmed compared to wild Atlantic salmon (Salmo salar)

Contaminants and fatty acid levels in farmed- versus wild Atlantic salmon have been a hot topic of debate in terms of food safety. The present study determined dioxins (polychlorinated dibenzo-p-dioxin and dibenzofuran), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), metals and fatty acids in wild and farmed Atlantic salmon. Contaminant levels of dioxins, PCBs, OCPs (DDT, dieldrin, lindane, chlordane, Mirex, and toxaphene), and mercury were higher in wild salmon than in farmed salmon, as were the concentrations of the essential elements selenium, copper, zinc and iron, and the marine omega-3 fatty acid docosahexaenoic acid (DHA). PBDE, endosulfan, pentachlorobenzene, hexachlorobenzene, cadmium and lead levels were low and comparable in both wild and farmed fish, and there was no significant difference in the marine omega-3 fatty acid eicosapentaenoic acid (EPA) concentration. The total fat content was significantly higher in farmed than wild salmon due to a higher content of both saturated and monounsaturated fatty acids, as well as a higher content of omega-6 fatty acids. The omega-3 to omega-6 fatty acid ratio was considerably lower in farmed than wild salmon due to the high level of omega-6 fatty acids. Contaminant concentrations in Atlantic salmon were well below maximum levels applicable in the European Union. Atlantic salmon, both farmed and wild, is a good source of EPA and DHA with a 200g portion per week contributing 3.2g or 2.8g respectively, being almost twice the intake considered adequate for adults by the European Food Safety Authority (i.e. 250mg/day or 1.75g/week).

"Eat as If You Could Save the Planet and Win!" Sustainability Integration into Nutrition for Exercise and Sport

Today's industrial food production contributes significantly to environmental degradation. Meat production accounts for the largest impact, including greenhouse gas emissions, land and water use. While food production and consumption are important aspects when addressing climate change, this article focuses predominantly on dietary change that promotes both health for planet and people with focus on athletes. Healthy, sustainable eating recommendations begin to appear in various governmental guidelines. However, there remains resistance to the suggested reductions in meat consumption. While food citizens are likely to choose what is good for them and the planet, others may not, unless healthy eating initiatives integrate creative food literacy approaches with experiential learning as a potential vehicle for change. This concept paper is organized in three sections: (1) Environmental impact of food; (2) health and sustainability connections; and (3) application in sports and exercise. For active individuals, this article focuses on the quantity of protein, highlighting meat and dairy, and quality of food, with topics such as organic production and biodiversity. Finally, the timing of when to integrate sustainability principles in sport nutrition is discussed, followed by practical applications for education and inclusion in team, institutional, and event operations.

Efficacy of fish intake on vitamin D status: a meta-analysis of randomized controlled trials

BACKGROUND

It is well known that fish is the major natural source of vitamin D in the diet; therefore, this meta-analysis investigated the influence of fish consumption in randomized controlled trials (RCTs) on serum 25-hydroxyvitamin D [25(OH)D] concentrations.

OBJECTIVE

A literature search was carried out in Medline, Embase, Web of Science, and the Cochrane Library (up to February 2014) for RCTs that investigated the effect of fish consumption on 25(OH)D concentrations in comparison to other dietary interventions.

RESULTS

Seven articles and 2 unpublished study data sets with 640 subjects and 14 study groups met the inclusion criteria and were included in this meta-analysis. Compared with controls, the consumption of fish increased 25(OH)D concentrations, on average, by 4.4 nmol/L (95% CI: 1.7, 7.1 nmol/L; P < 0.0001, I(2) = 25%; 9 studies).The type of the fish also played a key role: the consumption of fatty fish resulted in a mean difference of 6.8 nmol/L (95% CI: 3.7, 9.9 nmol/L; P < 0.0001, I(2) = 0%; 7 study groups), whereas for lean fish the mean difference was 1.9 nmol/L (95% CI: -2.3, 6.0 nmol/L; P < 0.38, I(2) = 37%; 7 study groups). Short-term studies (4-8 wk) showed a mean difference of 3.8 nmol/L (95% CI: 0.6, 6.9 nmol/L; P < 0.02, I(2) = 38%; 10 study groups), whereas in long-term studies (∼6 mo) the mean difference was 8.3 nmol/L (95% CI: 2.1, 14.5 nmol/L; P < 0.009, I(2) = 0%; 4 study groups).

CONCLUSION

As the major food source of vitamin D, fish consumption increases concentrations of 25(OH)D, although recommended fish intakes cannot optimize vitamin D status.

Long-chain omega-3 from low-trophic-level fish provides value to farmed seafood

Low-trophic-level fish are a crucial source of long-chain (LC) omega-3 fatty acids for farmed fish and humans. Many farm-raised fish species have a clear need for these nutrients. Farmed fish deposit the LC omega-3s in their flesh and transfer them up the food chain. However, the content of LC omega-3s in farm-raised seafood continues to decline, while the content of shorter-chain plant-sourced omega-3s, and pro-inflammtory omega-6s continue to increase. This reduces its nutritional worth. The value of low-trophic-level fish is often viewed merely as its price at the dock. Some reports and metrics steer public attention towards the mass balance between quantities of low-trophic-level fish and farmed seafood. However, the the nutritional value of seafood is more important than its mere quantities. The role of low-trophic-level fish in human nutrition, health, and wellbeing is a fundamental component of its economic value to society.

The effects of eating marine- or vegetable-fed farmed trout on the human plasma proteome profiles of healthy men

Most human intervention studies have examined the effects on a subset of risk factors, some of which may require long-term exposure. The plasma proteome may reflect the underlying changes in protein expression and activation, and this could be used to identify early risk markers. The aim of the present study was to evaluate the impact of regular fish intake on the plasma proteome. We recruited thirty healthy men aged 40 to 70 years, who were randomly allocated to a daily meal of chicken or trout raised on vegetable or marine feeds. Blood samples were collected before and after 8 weeks of intervention, and after the removal of the twelve most abundant proteins, plasma proteins were separated by two-dimensional gel electrophoresis. Protein spots < 66 kDa with a pI >4·3 visualised by silver staining were matched by two-dimensional imaging software. Within-subject changes in spots were compared between the treatment groups. Differentially affected spots were identified by matrix-assisted laser desorption ionisation-time of flight/time of flight MS and the human Swiss-Prot database. We found 23/681 abundant plasma protein spots, which were up- or down-regulated by the dietary treatment (P< 0·05, q< 0·30), and eighteen of these were identified. In each trout group, ten spots differed from those in subjects given the chicken meal, but only three of these were common, and only one spot differed between the two trout groups. In both groups, the affected plasma proteins were involved in biological processes such as regulation of vitamin A and haem transport, blood fibrinolysis and oxidative defence. Thus, regular fish intake affects the plasma proteome, and the changes may indicate novel mechanisms of effect.

Readily available sources of long-chain omega-3 oils: is farmed Australian seafood a better source of the good oil than wild-caught seafood?

Seafood consumption enhances intake of omega-3 long-chain (≥C₂₀) polyunsaturated fatty acids (termed LC omega-3 oils). Humans biosynthesize only small amounts of LC-omega-3, so they are considered semi-essential nutrients in our diet. Concern has been raised that farmed fish now contain lower LC omega-3 content than wild-harvested seafood due to the use of oil blending in diets fed to farmed fish. However, we observed that two major Australian farmed finfish species, Atlantic salmon (Salmo salar) and barramundi (Lates calcifer), have higher oil and LC omega-3 content than the same or other species from the wild, and remain an excellent means to achieve substantial intake of LC omega-3 oils. Notwithstanding, LC omega-3 oil content has decreased in these two farmed species, due largely to replacing dietary fish oil with poultry oil. For Atlantic salmon, LC omega-3 content decreased ~30%–50% between 2002 and 2013, and the omega-3/omega-6 ratio also decreased (>5:1 to <1:1). Australian consumers increasingly seek their LC omega-3 from supplements, therefore a range of supplement products were compared. The development and future application of oilseeds containing LC omega-3 oils and their incorporation in aquafeeds would allow these health-benefitting oils to be maximized in farmed Australian seafood. Such advances can assist with preventative health care, fisheries management, aquaculture nutrition, an innovative feed/food industry and ultimately towards improved consumer health.

Investigation of the effects of a high fish diet on inflammatory cytokines, blood pressure, and lipids in healthy older Australians

Background

Aging is a condition of chronic inflammation. In healthy Australians ≥64 years, the primary aim was to determine whether four servings/week of mixed fish (FISH) improves serum cytokines (i.e. C-reactive protein (CRP), IL-1, IL-6, TNF-α) compared to a diet low in fish (<1 serving/week, CONTROL); the secondary aims were to assess the effect of the diet on blood pressure and serum lipids (TC, HDL-C, TG, calculated LDL-C).

Methods

An 8-week randomized, parallel study, stratified by CRP (<3 mg/L vs. ≥3 mg/L) on entry to the study. Compliance was measured using 3-day weighed food records in weeks 1 and 7 of the study. A 12-h fasting blood sample was taken at baseline and 8-weeks for erythrocyte fatty acids as confirmation of compliance, and measurement of serum cytokines and lipids. Blood pressure was measured at both time points.

Results

Eighty participants completed the study (mean (SD) age: 69.6 (5.8) years). During week 1 of the study, mean ± SEM daily dietary intake of very long chain omega-3 polyunsaturated fatty acids (VLCN n-3 PUFA) in FISH vs. CONTROL was 1,676±129 mg vs. 27±5 mg (p<0.001). Mean (SD) gram intake of study fish and meat was 121 (45) g and 123 (78) g, for those allocated to FISH and CONTROL, respectively. Mean ± SEM percentage VLCN n-3 PUFA in erythrocytes at 8-weeks was higher in those allocated to FISH vs. CONTROL (10.2±0.2% vs. 8.2±0.3%, p<0.001). There was no between-group difference in CRP (n=80), IL-1β (n=33) or IL-6 (n=21) concentrations, blood pressure, or lipids, at 8-weeks.

Conclusions

Eight weeks consumption of four servings/week fish did not affect serum cytokine concentrations, blood pressure or lipids compared to a diet low in fish. In healthy older adults with low inflammatory burden, our results do not support that short-term consumption of mixed fish has a beneficial effect on selected cardiovascular biomarkers.

Influence of physical activity and nutrition on obesity-related immune function

Research examining immune function during obesity suggests that excessive adiposity is linked to impaired immune responses leading to pathology. The deleterious effects of obesity on immunity have been associated with the systemic proinflammatory profile generated by the secretory molecules derived from adipose cells. These include inflammatory peptides, such as TNF- α , CRP, and IL-6. Consequently, obesity is now characterized as a state of chronic low-grade systemic inflammation, a condition considerably linked to the development of comorbidity. Given the critical role of adipose tissue in the inflammatory process, especially in obese individuals, it becomes an important clinical objective to identify lifestyle factors that may affect the obesity-immune system relationship. For instance, stress, physical activity, and nutrition have each shown to be a significant lifestyle factor influencing the inflammatory profile associated with the state of obesity. Therefore, the purpose of this review is to comprehensively evaluate the impact of lifestyle factors, in particular psychological stress, physical activity, and nutrition, on obesity-related immune function with specific focus on inflammation.

Immunometabolic role of long-chain omega-3 fatty acids in obesity-induced inflammation

Inflammation links obesity with the development of insulin resistance. Macrophages and phagocytic immune cells communicate with metabolic tissues to direct an inflammatory response caused by overnutrition and expanding adipose tissue. Marine-derived omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), modulate inflammatory signalling events, providing various anti-inflammatory and cardioprotective benefits. Moreover, EPA and DHA may improve insulin sensitivity by generating proresolving lipid mediators and promoting alternatively activated macrophages. This review will assess the role of EPA and DHA in ameliorating obesity-induced inflammation, evaluating clinical evidence and mechanisms of action. The pathophysiology of insulin resistance resulting from obesity-induced inflammation will be discussed, highlighting the relationship between metabolism and immunity, and in particular, how EPA and DHA work with both systems to modulate immunometabolic complications and chronic disease.

Alternative sources of omega-3 fats: can we find a sustainable substitute for fish?

Increasing demand for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) containing fish oils is putting pressure on fish species and numbers. Fisheries provide fish for human consumption, supplement production and fish feeds and are currently supplying fish at a maximum historical rate, suggesting mass-scale fishing is no longer sustainable. However, the health properties of EPA and DHA long-chain (LC) omega-3 polyunsaturated fatty acids (PUFA) demonstrate the necessity for these oils in our diets. EPA and DHA from fish oils show favourable effects in inflammatory bowel disease, some cancers and cardiovascular complications. The high prevalence of these diseases worldwide indicates the requirement for alternative sources of LC-PUFA. Strategies have included plant-based fish diets, although this may compromise the health benefits associated with fish oils. Alternatively, stearidonic acid, the product of α-linolenic acid desaturation, may act as an EPA-enhancing fatty acid. Additionally, algae oils may be a promising omega-3 PUFA source for the future. Algae are beneficial for multiple industries, offering a source of biodiesel and livestock feeds. However, further research is required to develop efficient and sustainable LC-PUFA production from algae. This paper summarises the recent research for developing prospective substitutes for omega-3 PUFA and the current limitations that are faced.

Omega-3 fatty acids, oxidative stress, and leukocyte telomere length: A randomized controlled trial

Shorter telomeres have been associated with poor health behaviors, age-related diseases, and early mortality. Telomere length is regulated by the enzyme telomerase, and is linked to exposure to proinflammatory cytokines and oxidative stress. In our recent randomized controlled trial, omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation lowered the concentration of serum proinflammatory cytokines. This study assessed whether n-3 PUFA supplementation also affected leukocyte telomere length, telomerase, and oxidative stress. In addition to testing for group differences, changes in the continuous n-6:n-3 PUFA ratio were assessed to account for individual differences in adherence, absorption, and metabolism. The double-blind four-month trial included 106 healthy sedentary overweight middle-aged and older adults who received (1) 2.5g/day n-3 PUFAs, (2) l.25g/day n-3 PUFAs, or (3) placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Supplementation significantly lowered oxidative stress as measured by F2-isoprostanes (p=0.02). The estimated geometric mean log-F2-isoprostanes values were 15% lower in the two supplemented groups compared to placebo. Although group differences for telomerase and telomere length were nonsignificant, changes in the n-6:n-3 PUFA plasma ratios helped clarify the intervention's impact: telomere length increased with decreasing n-6:n-3 ratios, p=0.02. The data suggest that lower n-6:n-3 PUFA ratios can impact cell aging. The triad of inflammation, oxidative stress, and immune cell aging represents important pre-disease mechanisms that may be ameliorated through nutritional interventions. This translational research broadens our understanding of the potential impact of the n-6:n-3 PUFA balance. ClinicalTrials.gov identifier: NCT00385723.

Intake of farmed Atlantic salmon fed soybean oil increases insulin resistance and hepatic lipid accumulation in mice

Background

To ensure sustainable aquaculture, fish derived raw materials are replaced by vegetable ingredients. Fatty acid composition and contaminant status of farmed Atlantic salmon (Salmo salar L.) are affected by the use of plant ingredients and a spillover effect on consumers is thus expected. Here we aimed to compare the effects of intake of Atlantic salmon fed fish oil (FO) with intake of Atlantic salmon fed a high proportion of vegetable oils (VOs) on development of insulin resistance and obesity in mice.

Methodology/principal findings

Atlantic salmon were fed diets where FO was partly (80%) replaced with three different VOs; rapeseed oil (RO), olive oil (OO) or soy bean oil (SO). Fillets from Atlantic salmon were subsequently used to prepare Western diets (WD) for a mouse feeding trial. Partial replacement of FO with VOs reduced the levels of polychlorinated biphenyls (PCB) and dichloro-diphenyl-tricloroethanes (DDT) with more than 50% in salmon fillets, in WDs containing the fillets, and in white adipose tissue from mice consuming the WDs. Replacement with VOs, SO in particular, lowered the n−3 polyunsaturated fatty acid (PUFA) content and increased n−6 PUFA levels in the salmon fillets, in the prepared WDs, and in red blood cells collected from mice consuming the WDs. Replacing FO with VO did not influence obesity development in the mice, but replacement of FO with RO improved glucose tolerance. Compared with WD-FO fed mice, feeding mice WD-SO containing lower PCB and DDT levels but high levels of linoleic acid (LA), exaggerated insulin resistance and increased accumulation of fat in the liver.

Conclusion/Significance

Replacement of FO with VOs in aqua feed for farmed salmon had markedly different spillover effects on metabolism in mice. Our results suggest that the content of LA in VOs may be a matter of concern that warrants further investigation.

Survey of n-3 and n-6 polyunsaturated fatty acids in fish and fish products

BACKGROUND

The imbalance of the n-3/n-6 ratio in the Western diet is characterised by a low intake of n-3 long-chain (LC) PUFA and a concurrent high intake of n-6 PUFA. Fish, in particular marine fish, is a unique source of n-3 LC PUFA. However, FA composition of consumed fish changed, due to the increasing usage of n-6 PUFA-rich vegetable oils in aquaculture feed and in fish processing (frying) which both lead to a further shift in n-6 PUFA to the detriment of n-3 LC PUFA.The aim of this study was to determine the ratio of n-3/n-6 including the contents of EPA and DHA in fish fillets and fish products from the German market (n=123). Furthermore, the study focussed on the FA content in farmed salmon compared to wild salmon as well as in processed Alaska pollock fillet, e.g., fish fingers.

RESULTS

Total fat and FA content in fish products varied considerably depending on fish species, feed management, and food processing. Mackerel, herring and trout fillets characteristically contained adequate dietary amounts of absolute EPA and DHA, due to their high fat contents. However, despite a lower fat content, tuna, pollock, and Alaska pollock can contribute considerable amounts of EPA and DHA to the human supply.Farmed salmon are an appropriate source of EPA and DHA owing to their higher fat content compared to wild salmon (12.3 vs. 2.1 wt %), however with elevated SFA, n-9 and n-6 FA contents representing the use of vegetable oils and oilseeds in aquaculture feed. The n-3/n-6 ratio was deteriorated (2.9 vs. 12.4) but still acceptable. Compared to pure fish fillets, breaded and pre-fried Alaska pollock fillet contained extraordinarily high fat and n-6 PUFA levels.

CONCLUSIONS

Since fish species vary with respect to their n-3 LC PUFA contents, eating a variety of fish is advisable. High n-6 PUFA containing pre-fried fish support the imbalance of n-3/n-6 ratio in the Western diet. Thus, consumption of pure fish fillets is to be favoured. The lower n-3 PUFA portion in farmed fish can be offset by the higher fat content, however, with an unfavourable FA distribution compared to wild fellows.

The effect of dietary walnuts compared to fatty fish on eicosanoids, cytokines, soluble endothelial adhesion molecules and lymphocyte subsets: a randomized, controlled crossover trial

We tested the hypothesis that walnut consumption can exert effects on markers of inflammation and endothelial activation similar to those produced by fish consumption. In a crossover dietary intervention trial, 25 normal to mildly hyperlipidemic men and women were randomly assigned to one of three isoenergetic diets: a walnut diet incorporating 42.5 g of walnuts per 10.1 mJ 6 times per week (1.8% of energy n-3 fat); a fish diet providing 113 g of fatty fish per 10.1 mJ 2 times per week (0.8% of energy n-3 fat), or a control diet (no nuts or fish, 0.4% of energy n-3 fat) for 4 weeks on each diet. Both the walnut and fish diets inhibited circulating concentrations of prostaglandin E metabolite (PGEM) and 11-dehydro thromboxane B2, but demonstrated no effect on blood interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α¯ (TNF-α¯), and C-reactive protein (CRP) or the number of circulating lymphocyte subsets. On the walnut diet the proportion of plasma phospholipid α¯-linolenic acid (ALA) increased 140% and arachidonic acid (AA) decreased 7% compared to both the control and fish diets. The proportion of plasma phospholipid eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increased about 200% and 900% respectively on the fish diet relative to either the control or walnut diet. The walnut diet inhibited E-selectin by 12.7% relative to the fish diet, and the fish diet inhibited secretory intercellular adhesion molecule-1 (s-ICAM-1) by 4.5% relative to the control diet. Both walnuts and fish in commonly consumed amounts may have modest albeit distinct effects on circulating adhesion molecules.

Effect of Omega-3 Polyunsaturated Fatty Acid Supplementation in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained atrial arrhythmia conferring a higher morbidity and mortality. Despite the increasing incidence of AF; available therapies are far from perfect. Dietary fish oils, containing omega 3 fatty acids, also called polyunsaturated fatty acid [PUFA] have demonstrated beneficial electrophysiological, autonomic and anti-inflammatory effects on both atrial and ventricular tissue. Multiple clinical trials, focusing on various subsets of patients with AF, have studied the role of PUFA and their potential role in reducing the incidence of this common arrhythmia. While PUFA appears to have a beneficial effect in the primary prevention of AF in the elderly with structural heart disease, this benefit has not been universally observed. In the secondary prevention of AF, PUFA seems to have a greater impact in the reducing AF in patients with paroxysmal or persistent AF, stages of AF associated with less atrial fibrosis and negative structural remodeling. However, AF suppression has not been consistently demonstrated in clinical trials. In patients undergoing heart surgery, increasing PUFA intake has yielded mixed results in terms of AF prevention post-operatively; however, increased PUFA has been associated with a reduction in hospital stay. Therefore recommending the use of PUFA for the purpose of AF reduction remains controversial. This is in part attributable to the complexity of AF. Other conflicting variables include: heterogeneous patient populations studied; variable dosing; duration of follow-up; comorbidities; and, concomitant pharmacotherapy. This review article reviews in detail available basic and clinical research studies of fish oil in the treatment of AF, and its role in the treatment of this common disorder.

ABBREVIATIONS

AF=Atrial fibrillation, CHS=Cardiovascular Health Study,CABG=Coronary artery bypass surgery, d=Day, DHA=Docosahexaenoic acid, EPA=Eicosapentaenoic acid, ERP= Effective refractory period, g=Gram, PAF= Paroxysmal atrial fibrillation, PeAF= Persistent atrial fibrillation PUFA= Polyunsaturated fatty acid.

Dietary sources of omega 3 fatty acids: public health risks and benefits

Omega 3 fatty acids can be obtained from several sources, and should be added to the daily diet to enjoy a good health and to prevent many diseases. Worldwide, general population use omega-3 fatty acid supplements and enriched foods to get and maintain adequate amounts of these fatty acids. The aim of this paper was to review main scientific evidence regarding the public health risks and benefits of the dietary sources of omega-3 fatty acids. A systematic literature search was performed, and one hundred and forty-five articles were included in the results for their methodological quality. The literature described benefits and risks of algal, fish oil, plant, enriched dairy products, animal-derived food, krill oil, and seal oil omega-3 fatty acids.

Effects of n-3 PUFA supplementation on plasma soluble adhesion molecules: a meta-analysis of randomized controlled trials

BACKGROUND

Previous studies indicate that oral supplementation with n-3 PUFA protects against atherosclerotic disease by inhibiting inflammatory processes, which underlie atherosclerosis and are reflected by the plasma concentrations of soluble adhesion molecules. However, consistent results were not obtained among studies.

OBJECTIVE

The objective was to assess the effects of n-3 PUFA supplementation on plasma concentrations of soluble adhesion molecules.

DESIGN

We conducted a meta-analysis of randomized controlled trials identified from PubMed, Embase, the Cochrane Library, and reference lists of relevant articles and reviews.

RESULTS

Eighteen studies were included. n-3 PUFA supplementation reduced plasma concentrations of soluble intercellular adhesion molecule-1 [sICAM-1; weighted mean difference (WMD): -5.17; 95% CI: -10.07, -0.27; P = 0.04] but had no significant effects on soluble vascular cell adhesion molecule-1 (WMD: -5.90; 95% CI: -17.63, 5.84; P = 0.32), soluble P-selectin (WMD: -1.53; 95% CI: -4.33, 1.28; P = 0.29), or soluble E-selectin (WMD: 0.46; 95% CI: -1.54, 2.46; P = 0.65). Subgroup analysis stratified by the subjects' health status showed that n-3 PUFA supplementation reduced sICAM-1 concentrations in healthy subjects (WMD: -8.87; 95% CI: -15.20, -2.53; P = 0.006; heterogeneity test: I² = 0%, P = 0.76) and in subjects with dyslipidemia (WMD: -15.31; 95% CI: -26.82, -3.81; P = 0.009; heterogeneity test: I² = 26%, P = 0.26).

CONCLUSIONS

n-3 PUFA supplementation can reduce plasma concentrations of sICAM-1. The effect is identified in both healthy subjects and subjects with dyslipidemia, which supports the hypothesis that n-3 PUFA can be supplemented as a primary or secondary means for preventing the development as well as the progression of atherosclerosis.

Restoration of fillet n-3 long-chain polyunsaturated fatty acid is improved by a modified fish oil finishing diet strategy for atlantic salmon (Salmo salar L.) smolts fed palm fatty acid distillate

Reducing the lipid content in fish prior to feeding a fish oil finishing diet (FOFD) has the potential to improve n-3 long-chain (≥ C(20)) polyunsaturated fatty acid (LC-PUFA) restoration. This study had two main objectives: (1) determine whether feeding Atlantic salmon smolt a 75% palm fatty acid distillate diet (75PFAD) improves the apparent digestibility (AD) of saturated fatty acids (SFA) and (2) examine whether a food deprivation period after growth on 75PFAD leads to higher n-3 LC-PUFA restoration in the fillet when applying a FOFD. The AD of SFA was higher for 75PFAD compared to that of a fish oil (FO) diet. The relative level (as % total fatty acids (FA)) of n-3 LC-PUFA was higher in unfed fish compared to that in continuously fed fish after 21 and 28 day FOFD periods, respectively. Our results suggest that a food deprivation period prior to feeding a FOFD improves the efficiency of n-3 LC-PUFA restoration in the fillet of Atlantic salmon smolt.

Dietary inclusion of salmon, herring and pompano as oily fish reduces CVD risk markers in dyslipidaemic middle-aged and elderly Chinese women

Dietary intervention studies to assess the cardioprotective effects of oily fish are scarce in China. The present study aimed to examine the effects of the oily fish, Norwegian salmon, herring and local farmed pompano (Trachinotus ovatus) on CVD risk markers when included in the Chinese diet. In this 8-week, parallel-arm, randomised intervention study, 126 Chinese women with hypertriacylglycerolaemia, aged 35-70 years, were assigned to four groups to consume an experimental lunch containing 80 g fillets of either one of three oily fish or a mix of commonly eaten meats (pork/chicken/beef/lean fish) for 5 d/week. The results showed that inclusion of the three oily fish significantly increased the intake of n-3 long-chain PUFA (LC-PUFA) while decreasing the dietary n-6:n-3 PUFA ratio. Compared to the control group, significant increases of DHA, EPA+DHA and total n-3 PUFA in plasma choline phosphoglyceride were observed in the three oily fish groups. Plasma TAG levels were significantly reduced only in the salmon and herring groups. When compared to the baseline level, the three oily fish diets significantly decreased serum concentrations of TAG, apoB, apoCII and apoCIII, but only the salmon and herring diets significantly lowered TNF-α and raised adiponectin levels in serum. The salmon diet additionally decreased the serum concentration of IL-6. To conclude, dietary inclusion of salmon, herring and pompano as oily fish can effectively increase serum n-3 LC-PUFA content and are associated with favourable biochemical changes in dyslipidaemic middle-aged and elderly Chinese women, and these beneficial effects are mainly associated with n-3 LC-PUFA contents.

Omega-3 fatty acids and cardiovascular disease: effects on risk factors, molecular pathways, and clinical events

We reviewed available evidence for cardiovascular effects of n-3 polyunsaturated fatty acid (PUFA) consumption, focusing on long chain (seafood) n-3 PUFA, including their principal dietary sources, effects on physiological risk factors, potential molecular pathways and bioactive metabolites, effects on specific clinical endpoints, and existing dietary guidelines. Major dietary sources include fatty fish and other seafood. n-3 PUFA consumption lowers plasma triglycerides, resting heart rate, and blood pressure and might also improve myocardial filling and efficiency, lower inflammation, and improve vascular function. Experimental studies demonstrate direct anti-arrhythmic effects, which have been challenging to document in humans. n-3 PUFA affect a myriad of molecular pathways, including alteration of physical and chemical properties of cellular membranes, direct interaction with and modulation of membrane channels and proteins, regulation of gene expression via nuclear receptors and transcription factors, changes in eicosanoid profiles, and conversion of n-3 PUFA to bioactive metabolites. In prospective observational studies and adequately powered randomized clinical trials, benefits of n-3 PUFA seem most consistent for coronary heart disease mortality and sudden cardiac death. Potential effects on other cardiovascular outcomes are less-well-established, including conflicting evidence from observational studies and/or randomized trials for effects on nonfatal myocardial infarction, ischemic stroke, atrial fibrillation, recurrent ventricular arrhythmias, and heart failure. Research gaps include the relative importance of different physiological and molecular mechanisms, precise dose-responses of physiological and clinical effects, whether fish oil provides all the benefits of fish consumption, and clinical effects of plant-derived n-3 PUFA. Overall, current data provide strong concordant evidence that n-3 PUFA are bioactive compounds that reduce risk of cardiac death. National and international guidelines have converged on consistent recommendations for the general population to consume at least 250 mg/day of long-chain n-3 PUFA or at least 2 servings/week of oily fish.