Cardiac Arrhythmia Prevention in Ischemia and Reperfusion by Low-Dose Dietary Fish Oil Supplementation in Rats

Emulsification and stabilisation technologies used for the inclusion of lipophilic functional ingredients in food systems

Food industry is increasingly using functional ingredients to improve the food product quality. Lipid-containing functional ingredients are important sources of nutrients. This review examines the current state of emulsification and stabilisation technologies for incorporating lipophilic functional ingredients into food systems. Lipophilic functional ingredients, such as omega-3 fatty acids, carotenoids, and fat-soluble vitamins, offer numerous health benefits but present challenges due to their limited solubility in water-based food matrices. Emulsification techniques enable the dispersion of these ingredients in aqueous environments, facilitating their inclusion in a variety of food products. This review highlights recent advances in food emulsion formulation, emulsification methods and stabilisation techniques which, together, improve the stability and bioavailability of lipophilic compounds. The role of various emulsifiers, stabilizers, and encapsulation materials in enhancing the functionality of these ingredients is also explored. Furthermore, the review discusses different stabilisation techniques which can yield in emulsion in a solid or liquid state. By providing a comprehensive overview of current technologies, this review aims to guide future research and application in the development of functional foods enriched with lipophilic ingredients.

Transcriptomic analysis reveals the lipid metabolism-related gene regulatory characteristics and potential therapeutic agents for myocardial ischemia-reperfusion injury

Background

Impaired energy balance caused by lipid metabolism dysregulation is an essential mechanism of myocardial ischemia-reperfusion injury (MI/RI). This study aims to explore the lipid metabolism-related gene (LMRG) expression patterns in MI/RI and to find potential therapeutic agents.

Methods

Differential expression analysis was performed to screen the differentially expressed genes (DEGs) and LMRGs in the MI/RI-related dataset GSE61592. Enrichment and protein-protein interaction (PPI) analyses were performed to identify the key signaling pathways and genes. The expression trends of key LMRGs were validated by external datasets GSE160516 and GSE4105. The corresponding online databases predicted miRNAs, transcription factors (TFs), and potential therapeutic agents targeting key LMRGs. Finally, the identified LMRGs were confirmed in the H9C2 cell hypoxia-reoxygenation (H/R) model and the mouse MI/RI model.

Results

Enrichment analysis suggested that the "lipid metabolic process" was one of the critical pathways in MI/RI. Further differential expression analysis and PPI analysis identified 120 differentially expressed LMRGs and 15 key LMRGs. 126 miRNAs, 55 TFs, and 51 therapeutic agents were identified targeting these key LMRGs. Lastly, the expression trends of Acadm, Acadvl, and Suclg1 were confirmed by the external datasets, the H/R model and the MI/RI model.

Conclusion

Acadm, Acadvl, and Suclg1 may be the key genes involved in the MI/RI-related lipid metabolism dysregulation; and acting upon these factors may serve as a potential therapeutic strategy.

Intake of marine and plant-derived n-3 fatty acids and development of atherosclerotic cardiovascular disease in the Danish Diet, Cancer and Health cohort

PURPOSE

The objective of this study was to investigate the association between intake of seafood and plant-derived n-3 polyunsaturated fatty acids (PUFA) and development of total atherosclerotic cardiovascular disease (ASCVD) and acute major ischemic events.

METHODS

A total of 53,909 men and women were enrolled between 1993 and 1997 into the Danish Diet, Cancer and Health cohort and followed through nationwide Danish registries for development of total ASCVD defined as a first registration of myocardial infarction, peripheral artery disease, or ischemic stroke due to large artery atherosclerosis or small-vessel occlusion. At recruitment, the intake of the major marine n-3 PUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the plant-derived n-3 PUFA, alpha-linolenic acid (ALA), was assessed using a validated food frequency questionnaire. Statistical analyses were conducted using sex-stratified multivariable Cox proportional hazard regression models.

RESULTS

During a median of 13.5 years of follow-up, 3958 participants developed ASCVD including 3270 patients with an acute major ischemic event. In multivariable analyses including adjustment for established risk factors, we found no associations for intake of ALA, but indications of inverse associations between intake of EPA, DHA and EPA + DHA and the rate of total ASCVD and acute major ischemic events.

CONCLUSIONS

A high intake of marine n-3 PUFA was associated with a lower risk of total ASCVD and acute major ischemic events, whereas no association could be demonstrated for the plant-derived ALA.

Examining dietary behaviours, diet quality, motives and supplementation use in physically active individuals following vegetarian-based eating patterns

The adoption of vegetarian-based dietary patterns among athletes has been gaining popularity. However, limited research examines the dietary behaviours within this group. Therefore, the aim of this study was to examine self-reported dietary behaviours in a cohort of physically active individuals following vegetarian-based dietary patterns, recruited via social media. A 52-item online survey was created with questions related to demographics, physical activity, eating patterns and supplementation use. An external link to the Australian Automated Self-Administered 24-h (ASA24-AU) recall was included to examine nutrient intakes. Dietary quality was assessed using the Alternate Healthy Eating Index-2010 (AHEI-2010) and the Dietary Phytochemical Index (DPI) tools. A total of 781 (84.8%) respondents completed the survey in 2018. Principal motives for adhering to a vegetarian-based dietary pattern included animal rights (86.5%), environmental concerns (75.4%), health reasons (69.6%) and improving physical performance (24.1%). Vitamin B12 was the most commonly reported supplement (58.1%) followed by protein powder (36.3%) and vitamin D (35.9%). A total of 133 respondents completed the ASA24-AU dietary recall with generally adequate nutrient intakes and a high-quality diet as assessed by the AHEI-2010 and DPI. A significant minority of physically active individuals following vegetarian-based diets do so with the aspiration of improving their exercise performance. Dietary quality was considered high in this group for recreational physical activity, although intakes of vitamin B12 and LC n-3 PUFA were low.

Diet and Sudden Death: How to Reduce the Risk

In addition to the association of dietary patterns, specific foods and nutrients with several diseases, including cardiovascular disease and mortality, there is also strong emerging evidence of an association of dietary patterns with the risk of sudden cardiac death (SCD). In this comprehensive review, data are presented and analyzed about foods and diets that mitigate the risk of ventricular arrhythmias (VAs) and SCD, but also about arrhythmogenic nutritional elements and patterns that seem to enhance or facilitate potentially malignant VAs and SCD. The antiarrhythmic or protective group comprises fish, nuts and other foods enriched in omega-3 polyunsaturated fatty acids, the Mediterranean and other healthy diets, vitamins E, A and D and certain minerals (magnesium, potassium, selenium). The arrhythmogenic-food group includes saturated fat, trans fats, ketogenic and liquid protein diets, the Southern and other unhealthy diets, energy drinks and excessive caffeine intake, as well as heavy alcohol drinking. Relevant antiarrhythmic mechanisms include modification of cell membrane structure by n-3 polyunsaturated fatty acids, their direct effect on calcium channels and cardiomyocytes and their important role in eicosanoid metabolism, enhancing myocyte electric stability, reducing vulnerability to VAs, lowering heart rate, and improving heart rate variability, each of which is a risk factor for SCD. Contrarily, saturated fat causes calcium handling abnormalities and calcium overload in cardiomyocytes, while a high-fat diet causes mitochondrial dysfunction that dysregulates a variety of ion channels promoting VAs and SCD. Free fatty acids have been considered proarrhythmic and implicated in facilitating SCD; thus, diets increasing free fatty acids, e.g., ketogenic diets, should be discouraged and replaced with diets enriched with polyunsaturated fatty acids, which can also reduce free fatty acids. All available relevant data on this important topic are herein reviewed, large studies and meta-analyses and pertinent advisories are tabulated, while protective (antiarrhythmic) and arrhythmogenic specific diet constituents are pictorially illustrated.

The Effects of Fish Oil on Cardiovascular Diseases: Systematical Evaluation and Recent Advance

Fish oil is rich in unsaturated fatty acids, i.e., eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both of which are widely distributed in the body such as heart and brain. In vivo and in vitro experiments showed that unsaturated fatty acids may have effects of anti-inflammation, anti-oxidation, protecting vascular endothelial cells, thrombosis inhibition, modifying autonomic nerve function, improving left ventricular remodeling, and regulating blood lipid. Given the relevance to public health, there has been increasing interest in the research of potential cardioprotective effects of fish oil. Accumulated evidence showed that fish oil supplementation may reduce the risk of cardiovascular events, and, in specific, it may have potential benefits in improving the prognosis of patients with hypertension, coronary heart disease, cardiac arrhythmias, or heart failure; however, some studies yielded inconsistent results. In this article, we performed an updated systematical review in order to provide a contemporary understanding with regard to the effects of fish oil on cardiovascular diseases.

The influence of a basic military training diet on whole blood fatty acid profile and the Omega-3 Index of Australian Army recruits

This study described the whole blood fatty acid profile and Omega-3 Index (O3I) of Australian Army recruits at the commencement and completion of basic military training (BMT). Eighty (80) males (17-34 y, 77.4±13.0 kg, 43.5±4.3 mL/kg/min) and 37 females (17-45 y, 64.3±8.8 kg, 39.3±2.7 mL/kg/min) volunteered to participate (N=117). Whole blood samples of each recruit were collected using a finger prick in weeks 1 and 11 (n=82) and analysed via gas chromatography for the relative proportions of each fatty acid (mean [95% CI]). The macronutrient characteristics of the diet offerings was also determined. At commencement there was a low omega-3 status (sum of omega-3; 4.95% [4.82-5.07]) and O3I (5.03% [4.90-5.16]) and no recruit recorded an O3I >8% (desirable). The omega-6/omega-3 (7.04 [6.85-7.23]) and arachidonic acid / eicosapentaenoic acid (AA/EPA) (18.70 [17.86-19.53]) ratios for the cohort were also undesirable. The BMT mess menu provided a maximum of 190 mg/day of eicosapentaenoic acid (EPA) and 260 mg/day of docosahexaenoic acid (DHA). The O3I of the recruits was lower by week 11 (4.62% [4.51-4.78], p<0.05), the omega-6/omega-3 increased (7.27 [7.07-7.47] p<0.05) and the AA/EPA remained elevated (17.85 [16.89-18.81]). In conclusion, Australian Army recruits' omega-3 status remained undesirable during BMT and deserves nutritional attention. Novelty Bullets • Australian Army recruits' Omega-3 Index, at the commencement of BMT, was reflective of the Western-style diet. • The BMT diet offered minimum opportunity for daily EPA and DHA consumption. • Every recruit experienced a further reduction of their Omega-3 Index during BMT.

Heme-oxygenase and lipid mediators in obesity and associated cardiometabolic diseases: Therapeutic implications

Obesity-mediated metabolic syndrome remains the leading cause of death worldwide. Among many potential targets for pharmacological intervention, a promising strategy involves the heme oxygenase (HO) system, specifically its inducible form, HO-1. This review collects and updates much of the current knowledge relevant to pharmacology and clinical medicine concerning HO-1 in metabolic diseases and its effect on lipid metabolism. HO-1 has pleotropic effects that collectively reduce inflammation, while increasing vasodilation and insulin and leptin sensitivity. Recent reports indicate that HO-1 with its antioxidants via the effect of bilirubin increases formation of biologically active lipid metabolites such as epoxyeicosatrienoic acid (EET), omega-3 and other polyunsaturated fatty acids (PUFAs). Similarly, HO-1and bilirubin are potential therapeutic targets in the treatment of fat-induced liver diseases. HO-1-mediated upregulation of EET is capable not only of reversing endothelial dysfunction and hypertension, but also of reversing cardiac remodeling, a hallmark of the metabolic syndrome. This process involves browning of white fat tissue (i.e. formation of healthy adipocytes) and reduced lipotoxicity, which otherwise will be toxic to the heart. More importantly, this review examines the activity of EET in biological systems and a series of pathways that explain its mechanism of action and discusses how these might be exploited for potential therapeutic use. We also discuss the link between cardiac ectopic fat deposition and cardiac function in humans, which is similar to that described in obese mice and is regulated by HO-1-EET-PGC1α signaling, a potent negative regulator of the inflammatory adipokine NOV.

DHA-Rich Fish Oil Increases the Omega-3 Index in Healthy Adults and Slows Resting Heart Rate without Altering Cardiac Autonomic Reflex Modulation

Regular fish consumption, a rich source of long-chain omega-3 (ω-3) docosahexaenoic acid (DHA), modifies cardiac electrophysiology. However, human studies investigating fish oil and cardiac electrophysiology have predominantly supplemented therapeutic (high) doses of fish oil (often ω-3 eicosapentaenoic acid (EPA) rich sources). This study examined whether non-therapeutic doses of DHA-rich fish oil modulate cardiac electrophysiology at rest and during cardiovascular reflex challenges to the same extent, if at all, in young healthy adults.

Participants (N = 20) were supplemented (double-blinded) with (2x1g.day^-1) soy oil (Control n = 9) or DHA-rich tuna fish oil (FO n = 11) providing DHA: 560 mg and EPA: 140 mg. The Omega-3 Index (O3I; erythrocyte membrane % EPA + DHA), heart rate (HR) and HR variability (HRV) were analyzed during rest, maximal isometric handgrip and cold diving reflex challenges at baseline and following 8 weeks.

The baseline O3I (Control: 5.1 ± 1.0; FO: 5.4 ± 0.9; P > 0.05), resting HR (Control: 65 ± 12bpm; FO: 66 ± 8bpm; P > 0.05) and HRV metrics did not significantly differ between the groups prior to supplementation. Relative to the control group, the O3I was increased (Control: 5.0 ± 1.1; FO: 7.8 ± 1.2; P < 0.001), and resting HR was slowed in the FO group following supplementation (Control: 66 ± 9bpm; FO: 61 ± 6bpm; P = 0.046). However, no significant (P > 0.05) between-group differences were observed in HR responsiveness or any indices of HRV during reflex challenges.

In young healthy adults, dietary achievable doses of ω-3 DHA-rich fish oil exerted a direct slowing effect on resting HR, without compromising the HR response to either dominant sympathetic or parasympathetic modulation.

Nutrigenomics of Dietary Lipids

Dietary lipids have a major role in nutrition, not only for their fuel value, but also as essential and bioactive nutrients. This narrative review aims to describe the current evidence on nutrigenomic effects of dietary lipids. Firstly, the different chemical and biological properties of fatty acids contained both in plant- and animal-based food are illustrated. A description of lipid bioavailability, bioaccessibility, and lipotoxicity is provided, together with an overview of the modulatory role of lipids as pro- or anti-inflammatory agents. Current findings concerning the metabolic impact of lipids on gene expression, epigenome, and gut microbiome in animal and human studies are summarized. Finally, the effect of the individual’s genetic make-up on lipid metabolism is described. The main goal is to provide an overview about the interaction between dietary lipids and the genome, by identifying and discussing recent scientific evidence, recognizing strengths and weaknesses, to address future investigations and fill the gaps in the current knowledge on metabolic impact of dietary fats on health.

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.

A Cross-Sectional Comparison of the Whole Blood Fatty Acid Profile and Omega-3 Index of Male Vegan and Omnivorous Endurance Athletes

Background: Evaluation of the dietary fat consumption in athletes following vegan diets is scarce. The aim of this study was to explore the intakes, availability, and uptake of physiologically relevant fatty acids into whole blood, and consequently the Omega-3 Index (O3I) of endurance athletes following vegan and omnivorous dietary patterns.Materials: Males aged 18 to 55 years, engaging in ≥ four hours of training/week and following a vegan (>6 months) or omnivorous dietary pattern were eligible to participate. A 7-day food and training diary was collected and an incremental ramp running protocol used to determine peak aerobic capacity. A finger prick blood sample was collected to determine the whole blood fatty acid profile and O3I. Participants were grouped as following a vegan or omnivorous diet matched for age, training volume and peak aerobic capacity.Results: The vegan group (n = 12) consumed significantly less dietary total fat (122.2 g/day vs 84.1 g/day p = 0.007), saturated fat (43.74 g/day vs 18.42 g/day p < 0.0001), monounsaturated fat (49.6 g/day vs 35.64 g/day p = 0.039) and long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) compared to the omnivorous group (n = 8). Between group differences in whole blood fatty acid concentrations were observed including; linoleic, eicosapentaenoic, docosahexaenoic, n-6:n-3 and AA:EPA ratios. O3I in both groups were suboptimal (vegan: 4.13%, omnivorous: 5.40%) in terms of cardiac risk.Conclusion: Male endurance athletes should ensure their dietary LC n-3 PUFA intakes, particularly EPA and DHA fatty acids are sufficient to optimize their O3I.