The Potential Cardiometabolic Effects of Long-Chain ω-3 Polyunsaturated Fatty Acids: Recent Updates and Controversies

The Cardioprotective Effects of Polyunsaturated Fatty Acids Depends on the Balance Between Their Anti- and Pro-Oxidative Properties

Polyunsaturated fatty acids (PUFAs) are not only structural components of membrane phospholipids and energy storage molecules in cells. PUFAs are important factors that regulate various biological functions, including inflammation, oxidation, and immunity. Both n-3 and n-6 PUFAs from cell membranes can be metabolized into pro-inflammatory and anti-inflammatory metabolites that, in turn, influence cardiovascular health in humans. The role that PUFAs play in organisms depends primarily on their structure, quantity, and the availability of enzymes responsible for their metabolism. n-3 PUFAs, such as eicosapentaenoic (EPA) and docosahexaenoic (DHA), are generally known for anti-inflammatory and atheroprotective properties. On the other hand, n-6 FAs, such as arachidonic acid (AA), are precursors of lipid mediators that display mostly pro-inflammatory properties and may attenuate the efficacy of n-3 by competition for the same enzymes. However, a completely different light on the role of PUFAs was shed due to studies on the influence of PUFAs on new-onset atrial fibrillation. This review analyzes the role of PUFAs and PUFA derivatives in health-related effects, considering both confirmed benefits and newly arising controversies.

Unveiling the Lipid Features and Valorization Potential of Atlantic Salmon (Salmo salar) Heads

The sustainable utilization of co-products derived from the salmon processing industry is crucial for enhancing the viability and decreasing the environmental footprint of both capture and aquaculture operations. Salmon (Salmo salar) is one of the most consumed fish worldwide and a major species produced in aquaculture. As such, significant quantities of salmon co-products are produced in pre-commercialization processing/steaking procedures. The present study characterized a specific co-product derived from the processing of salmon: minced salmon heads. More specifically, this work aimed to reveal the nutritional profile of this co-product, with a special focus on its lipid content, including thoroughly profiling fatty acids and fully appraising the composition in complex lipids (polar lipids and triglycerides) for the first time. The antioxidant potential of lipid extracts from this salmon co-product was also studied in order to bioprospect lipid functional properties and possibly unveil new pathways for added-value applications. Our analysis indicated that these minced salmon heads are exceptionally rich in lipids. Oleic acid is the most prevalent fatty acid in this co-product, followed by palmitic acid, stearic acid, and linoleic acid. Moreover, relevant lipid indexes inferred from the fatty acid composition of this co-product revealed good nutritional traits. Lipidome analysis revealed that triglycerides were clearly the predominant lipid class present in this co-product while phospholipids, as well as ceramides, were also present, although in minimal quantities. The bioprospecting of antioxidant activity in the lipid extracts of the minced salmon heads revealed limited results. Given the high concentration of triglycerides, minced salmon heads can constitute a valuable resource for industrial applications from the production of fish oil to biodiesel (as triglycerides can be easily converted into fatty acid methyl esters), as well as possible ingredients for cosmetics, capitalizing on their alluring emollient properties. Overall, the valorization of minced salmon heads, major co-products derived from the processing of one of the most intensively farmed fish in the world, not only offers economic benefits but also contributes to the sustainability of the salmon processing industry by reducing waste and promoting a more efficient use of marine bioresources.

The role of nutrition-related clinical trials in informing dietary recommendations for health and treatment of diseases

Dietary guidance is based on a robust evidence base that includes high-quality clinical trials, of which some have been designed to establish causal relationships between dietary interventions and ASCVD risk reduction. However, the complexity associated with conducting these trials has resulted in criticism of nutrition and dietary recommendations because the strength and quality of evidence falls short of that for some pharmaceutical interventions. In this paper, we aim to promote greater awareness of the nutrition-related clinical trials that have been conducted showing ASCVD benefits and how this evidence has contributed to dietary recommendations. Compared to clinical trials of pharmaceutical agents, nutrition-related clinical trials have several unique considerations, including complexities of intervention design, challenges related to the blinding of participants to treatment, modest effect magnitudes, variability in baseline dietary exposures, absence of objective dietary adherence biomarkers, achieving sustained participant adherence, and the significant timeline for endpoint responses. Evidence-based dietary recommendations are made based on multiple lines of evidence including that from randomized controlled trials, epidemiological studies, as well as animal and in vitro studies. This research has provided foundational evidence for the role of diet in prevention, management, and treatment of ASCVD. Based on the clinical trials that have been conducted, a strong consensus has evolved regarding the key elements of healthy dietary patterns that decrease ASCVD risk. Going forward, implementation research is needed to identify effective translation approaches to increase adherence to evidence-based dietary recommendations.

Walnut extract protects against hepatic inflammation and toxicity induced by a high-fat diet

A high-fat diet (HFD) is one of the main causes of obesity and metabolic diseases. The liver is particularly affected by HFD causing metabolic dysfunction associated with fatty liver disease. Therefore, different strategies are used to mitigate the negative effects of HFD. This study aimed to assess the protective effects of walnut extract against HFD-induced toxicity in mice. The mice were fed HFD and walnut extract alone or in combination. The walnut extract was analyzed for composition using high-performance liquid chromatography with a diode array detector (HPLC-DAD) and ultra-high-performance liquid chromatography with mass spectrometry (UHPLC-MS/MS). Serum lipid profile; liver histology; hepatic antioxidants such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), lipid peroxidation (TBARS), and reduced glutathione (GSH); inflammatory markers like IL-6 and TNF-α; and phospholipids were determined. Results showed that phenolic acids, epicatechin, catechin, benzaldehyde, and juglone were the main constituents in the extract. The HFD group showed increased hepatic fat accumulation as evidenced by biochemical and histopathological examinations compared to the control animals. The HFD group mice also showed increased body and cardiac weights, modified lipid profiles, decreased antioxidant status, and increased levels of hepatic inflammatory markers. The weights of the body and heart, lipid profiles, antioxidant contents (CAT, SOD, GSH-Px, TBARS, and GSH), and pro-inflammatory cytokines (IL-6 and TNF-α) were all normalized by consuming walnut extract. Similarly, the HFD group had significantly high amounts of hepatic lipase, phospholipid, and lysophospholipid levels, which were improved by walnut extract. In conclusion, walnut extract has been shown to play a unique role in promoting the recovery of liver damage caused by a high-fat diet.

ω-6 and ω-3 Polyunsaturated Fatty Acids: Inflammation, Obesity and Foods of Animal Resources

Obesity, as defined by the World Health Organization (WHO), is excessive fat accumulation that can pose health risks and is a disorder of the energy homeostasis system. In typical westernized diets, ω-6 polyunsaturated fatty acids (PUFAs) vastly exceed the amount of ω-3 PUFAs, with ω-6/ω-3 ratios ranging from 10:1 to 25:1. ω-6 PUFAs, such as arachidonic acid, have pro-inflammatory effects and increase obesity. On the other hand, ω-3 PUFAs, including eicosapentaenoic acid and docosahexaenoic acid, have anti-inflammatory and anti-obesity effects. Linoleic acid (LA) and alpha-linolenic acid (ALA) are synthesized in almost all higher plants, algae, and some fungi. However, in humans and animals, they are essential fatty acids and must be consumed through diet or supplementation. Therefore, balancing LA/ALA ratios is essential for obesity prevention and human health. Monogastric animals such as pigs and chickens can produce meat and eggs fortified with ω-3 PUFAs by controlling dietary fatty acid (FA). Additionally, ruminant animals such as feeder cattle and lactating dairy cows can opt for feed supplementation with ω-3 PUFAs sources and rumen-protected microencapsulated FAs or pasture finishing. This method can produce ω-3 PUFAs and conjugated linoleic acid (CLA) fortified meat, milk, and cheese. A high ω-6/ω-3 ratio is associated with pro-inflammation and obesity, whereas a balanced ratio reduces inflammation and obesity. Additionally, probiotics containing lactic acid bacteria are necessary, which reduces inflammation and obesity by converting ω-6 PUFAs into functional metabolites such as 10-hydroxy-cis-12-octadecenoic acid and CLA.

A Life-Stage Approach to Precision Nutrition: A Narrative Review

The concept of precision nutrition highlights the customization of nutrition to specific needs, emphasizing that a one-size-fits-all approach is not sufficient for either optimal nutrition or optimal health. Precision nutrition encompasses a range of factors, from broad strata of age and sex categories to personal characteristics such as lifestyle to an individual's unique genotype. This breadth of scope requires us to consider how precision nutrition can be implemented in an inclusive and appropriate way for individuals and groups within real-life populations. In this narrative review, we explore the potential of precision nutrition through a life-stage approach that emphasizes age- and gender-specific nutritional needs as these change across the lifespan. Focusing on adult life stages, we delineated trends in age-related conditions and health needs among Korean adults based on national-level survey data (KNHANES 2019-2021). We also reviewed the intake of nutrients associated with these health needs to better understand how life-stage guided approaches to nutrition and supplementation could support optimal health. Looking beyond preventing deficiency or disease, we discuss how tailored supplementation of essential vitamins, minerals, and certain bioactive substances could promote healthy functioning. Finally, we discuss the complexities and challenges of developing multivitamin/multimineral supplements (MVMS) to support life-stage appropriate nutrition while maximizing adherence. Future prospects include leveraging advancements in intelligent technologies and dietary assessments for tracking nutrient intake and health indicators and using these to optimize MVMS formulations in ways that are sensitive to a person's needs and priorities/preferences at different life stages. By adopting a life-stage guided approach to nutrition, we can better support health and well-being across the lifespan.

Discovery of mass spectral peak markers and protein biomarkers in fish muscle exudates for rapid and precise recognition of fish species via magnetic beads (MBs) and mass spectrometry

In this study, muscle exudates from five fishes belonging to the family Sciaenidae, in the order Perciformes, were analyzed as models for the discovery of biomarkers by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). MagSi-weak cation exchange magnetic beads (WCX-MBs) were utilized for the enrichment of proteins from fish exudate samples, allowing protein biomarkers to be identified and subsequently used for fish species differentiation. Buffers with pH ranging from 4.0 to 9.0 can provide an environment for proteins in fish muscle exudate to bind to the WCX-MBs. The optimal enrichment based on WCX-MBs can be achieved when the exudate samples are diluted 100folds. More species-specific biomarkers in mass spectra can be identified when using WCX-MBs. The number of ions that can be considered as peak markers and can differentiate the analyzed fishes increases from 38 to 121 when using WCX-MBs to isolate peptides/protein in fish muscle exudate. Particularly, eight peak markers in mass spectra were assigned to be specific to Nibea albiflora (NA), three peak markers specific to Larimichthys crocea (LC), two peak markers specific to Miichthys miiuy (MM), seven peak markers specific to Collichthys lucidus (CL), and six peak markers specific to Larimichthys polyactis (LP). Furthermore, five proteins were identified based on the characterization of tryptic peptides and their potential to be biomarkers, of which four proteins specific to CL and one specific to LC were identified. The single-blind samples analysis demonstrated that these species-specific peak markers and protein biomarkers can be successfully utilized for corresponding fish recognition. The utilization of WCX-MBs can improve the discovery of fish species-specific biomarkers in fish muscle exudate samples. The present protocol holds potential of being a rapid and accurate identification tool for recognition of fish species.

Association between plasma long-chain polyunsaturated n-3 fatty acids concentrations and cognitive function: findings from NHANES III

Background

With increased life expectancy, cognitive decline has emerged as a prevalent neurodegenerative disorder.

Objective

This study aimed to examine the correlation between concentrations of Plasma long-chain n-3 polyunsaturated fatty acids (LCPUFAs) and cognitive performance in elderly Americans.

Methods

Data were analyzed from older adults enrolled in two NHANES cycles. Participants completed four cognitive assessments, including the Immediate Recall Test (IRT), Delayed Recall Test (DRT), Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST). Linear regression and restricted cubic spline modeling examined associations between plasma LCPUFAs levels and cognitive test outcomes.

Results

The cohort included 610 adults aged 69 years on average, 300 (49.2%) males and 310 (50.8%) females. The median LCPUFAs concentration was 309.4 μmol/L, with an interquartile range of 244.7-418.9 μmol/L. In unadjusted and adjusted generalized linear regression model analyses, circulating LCPUFAs exhibited significant positive correlations with DRT performance. No relationships were detected among those with chronic conditions (chronic heart failure, stroke, diabetes). A significant association between LCPUFAs levels and DRT scores was evident in males but not females.

Conclusion

Plasma LCPUFAs concentrations were significantly associated with DRT performance in males free of chronic illnesses, including heart failure, stroke, and diabetes.

ω-3 Polyunsaturated Fatty Acid Status Testing in Humans: A Narrative Review of Commercially Available Options

There is an increasing body of evidence supporting a link between low intakes of ω-3 long-chain polyunsaturated fatty acids (LCPUFA) and numerous diseases and health conditions. However, few people are achieving the levels of fish/seafood or eicosapentaenoic acid and docosahexaenoic acid intake recommended in national and international guidelines. Knowledge of a person's ω-3 LCPUFA status will benefit the interpretation of research results and could be expected to lead to an increased effort to increase intake. Dietary intake survey methods are often used as a surrogate for measuring ω-3 PUFA tissue status and its impact on health and functional outcomes. However, because individuals vary widely in their ability to digest and absorb ω-3 PUFA, analytical testing of biological samples is desirable to accurately evaluate ω-3 PUFA status. Adipose tissue is the reference biospecimen for measuring tissue fatty acids, but less-invasive methods, such as measurements in whole blood or its components (e.g., plasma, serum, red blood cell membranes) or breast milk are often used. Numerous commercial laboratories provide fatty acid testing of blood and breast milk samples by different methods and present their results in a variety of reports such as a full fatty acid profile, ω-3 and ω-6 fatty acid profiles, fatty acid ratios, as well as the Omega-3 Index, the Holman Omega-3 Test, OmegaScore, and OmegaCheck, among others. This narrative review provides information about the different ways to measure ω-3 LCPUFA status (including both dietary assessments and selected commercially available analytical tests of blood and breast milk samples) and discusses evidence linking increased ω-3 LCPUFA intake or status to improved health, focusing on cardiovascular, neurological, pregnancy, and eye health, in support of recommendations to increase ω-3 LCPUFA intake and testing.

Synbiotic Bacillus megaterium DSM 32963 and n-3 PUFA Salt Composition Elevates Pro-Resolving Lipid Mediator Levels in Healthy Subjects: A Randomized Controlled Study

Beneficial health effects of omega-3 polyunsaturated fatty acids (n-3 PUFA) are partly attributed to specialized pro-resolving mediators (SPMs), which promote inflammation resolution. Strategies to improve n-3 PUFA conversion to SPMs may, therefore, be useful to treat or prevent chronic inflammatory disorders. Here, we explored a synbiotic strategy to increase circulating SPM precursor levels. Healthy participants (n = 72) received either SynΩ3 (250 mg eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) lysine salts; two billion CFU Bacillus megaterium; n = 23), placebo (n = 24), or fish oil (300 mg EPA plus DHA; N = 25) capsules daily for 28 days in a randomized, double-blind placebo-controlled parallel 3-group design. Biomarkers were assessed at baseline and after 2 and 28 days of intervention. The primary analysis involved the comparison between SynΩ3 and placebo. In addition, SynΩ3 was compared to fish oil. The synbiotic SynΩ3 comprising Bacillus megaterium DSM 32963 and n-3 PUFA salts significantly increased circulating SPM precursor levels, including 18-hydroxy-eicosapentaenoic acid (18-HEPE) plus 5-HEPE, which was not achieved to this extent by fish oil with a similar n-3 PUFA content. Omega-3 indices were increased slightly by both SynΩ3 and fish oil. These findings suggest reconsidering conventional n-3 PUFA supplementation and testing the effectiveness of SynΩ3 particularly in conditions related to inflammation.

Differential Modulation by Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) of Mesenteric Fat and Macrophages and T Cells in Adipose Tissue of Obese fa/fa Zucker Rats

Polyunsaturated fatty acids (PUFAs) can alter adipose tissue function; however, the relative effects of plant and marine n3-PUFAs are less clear. Our objective was to directly compare the n3-PUFAs, plant-based α-linolenic acid (ALA) in flaxseed oil, and marine-based eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) in high-purity oils versus n6-PUFA containing linoleic acid (LA) for their effects on the adipose tissue and oral glucose tolerance of obese rats. Male fa/fa Zucker rats were assigned to faALA, faEPA, faDHA, and faLA groups and compared to baseline fa/fa rats (faBASE) and lean Zucker rats (lnLA). After 8 weeks, faEPA and faDHA had 11-14% lower body weight than faLA. The oral glucose tolerance and total body fat were unchanged, but faEPA had less mesenteric fat. faEPA and faDHA had fewer large adipocytes compared to faLA and faALA. EPA reduced macrophages in the adipose tissue of fa/fa rats compared to ALA and DHA, while faLA had the greatest macrophage infiltration. DHA decreased (~10-fold) T-cell infiltration compared to faBASE and faEPA, whereas faALA and faLA had an ~40% increase. The n3-PUFA diets attenuated tumour necrosis factor-α in adipose tissue compared to faBASE, while it was increased by LA in both genotypes. In conclusion, EPA and DHA target different aspects of inflammation in adipose tissue.

Marine Animal Co-Products-How Improving Their Use as Rich Sources of Health-Promoting Lipids Can Foster Sustainability

Marine lipids are recognized for their-health promoting features, mainly for being the primary sources of omega-3 fatty acids, and are therefore critical for human nutrition in an age when the global supply for these nutrients is experiencing an unprecedent pressure due to an ever-increasing demand. The seafood industry originates a considerable yield of co-products worldwide that, while already explored for other purposes, remain mostly undervalued as sustainable sources of healthy lipids, often being explored for low-value oil production. These co-products are especially appealing as lipid sources since, besides the well-known nutritional upside of marine animal fat, which is particularly rich in omega-3 polyunsaturated fatty acids, they also have interesting bioactive properties, which may garner them further interest, not only as food, but also for other high-end applications. Besides the added value that these co-products may represent as valuable lipid sources, there is also the obvious ecological upside of reducing seafood industry waste. In this sense, repurposing these bioresources will contribute to a more sustainable use of marine animal food, reducing the strain on already heavily depleted seafood stocks. Therefore, untapping the potential of marine animal co-products as valuable lipid sources aligns with both health and environmental goals by guaranteeing additional sources of healthy lipids and promoting more eco-conscious practices.

Does slaughter age affect amino acids and fatty acids profiles and health and nutritional values of male and female ROSS 308 broiler chicken breast muscle?

Chemical composition, amino acids (AAs), and fatty acid (FAs) profiles, and health and nutrition values of breast muscle of ROSS 308 broiler chickens were studied after being slaughtered at 28, 35, 42, and 49 d of age (n = 126 males and 126 females/slaughter age). The slaughter age significantly affected some AAs levels including glutamic acid, valine, isoleucine, histidine, and leucine, and some FAs level including capric acid, tetradecanoic acid, eicosanoic acid, total saturated fatty acids, 9-pentadecenoic acid, hexadecatetraenoic acid, α-linolenic acid, stearidonic acid, linoleic acid, dihomo-γ-linolenic acid, arachidonic acid, adrenic acid, omega 6, sum polyunsaturated fatty acids (Ʃ PUFAs), and unsaturation index. Subsequently, the slaughter age significantly affected some health indexes including the n-6/n-3 ratio, thrombogenic index, hypocholesterolemic/hypercholesterolemic ratio, and health-promoting index. Valine, leucine, isoleucine, histidine, and glutamic acid levels increased with increasing slaughter age until 35 d of age and then decreased with increasing slaughter age until 49 d of age. Moreover, the health indices of fatty acids were best at slaughter age of 35 d, followed by 49 d, and the lowest health-promoting indices were at 42 d, followed by 28 d. The sex did not affect (P ˃ 0.05) all the evaluating parameters including chemical composition, amino acid and fatty acid profiles, and related health indices. There was no significant interaction effect between sex and slaughter age in all evaluating parameters except in stearidonic acid level. In conclusion, amino acids and fatty acids profiles and health and nutritional values of male and female ROSS 308 broiler chicken breast muscle can be affected by slaughter age. The study provides valuable insights into the nutritional value of meat, including its composition, amino acid, and fatty acid profiles, and associated health indices, for both male and female fast-growing ROSS 308 broiler chickens, as the slaughter age increases.

The Anti-Aggregative Potential of Resolvin E1 on Human Platelets

Resolvin E1 is a metabolite of eicosapentaenoic acid (EPA) which is one of the omega-3 polyunsaturated fatty acids (omega-3 PUFAs). The antiplatelet properties of omega-3 PUFAs are well known, but the effect of resolvin E1 on platelets via the collagen receptors is extremely poorly reported. We investigated the effect of resolvin E1 on collagen-induced platelet aggregation, activation, and reactivity, and also platelet membrane fluidity. The ultimate and statistically significant results showed that resolvin E1 may inhibit platelet reactivity due to the reduction of collagen-induced platelet aggregation in platelet-rich plasma and isolated platelets, but not in whole blood. Also, resolvin E1 significantly reduced P-selectin exposure on collagen-stimulated platelets. Moreover, we demonstrated that resolvin E1 can maintain platelet membrane structure (without increasing membrane fluidity). The association between platelet reactivity and membrane fluidity, including resolvin E1 and collagen receptors requires further research. However, the goal of this study was to shed light on the molecular mechanisms behind the anti-aggregative effects of resolvin E1 on platelets, which are still not fully clarified. We also indicate an innovative research direction focused on further analysis and then use of omega-3 PUFAs metabolites as antiplatelet compounds for future applications in the treatment and prevention of cardiovascular diseases.