What Is the Most Effective Way of Increasing the Bioavailability of Dietary Long Chain Omega-3 Fatty Acids--Daily vs. Weekly Administration of Fish Oil?

The judicious use of finite marine resources can sustain Atlantic salmon (salmo salar) aquaculture to 2100 and beyond

The production of farmed Atlantic salmon (Salmo salar) is currently linked to finite marine resources, particularly fish oil (FO) and fish meal (FM). Understanding this relationship in a quantitative manner is imperative if this critical balance is to be maintained within sustainable limits as the industry grows. Here we project the potential production and associated growth of the Atlantic salmon aquaculture industry on the basis of a variety of FO and FM utilization scenarios in aquafeed. Reducing FO and FM dietary inclusion to 3% each could permit production growth of 2% per year until the turn of the century (2097 and beyond 2100, respectively), independent of a host of alternatives now being utilized-with three portions of salmon per week providing almost all the recommended weekly long-chain omega-3 fatty acids for human intake. The Atlantic salmon industry's positive annual growth can continue in an era of finite marine resource availability-without the need for additional finite marine resource inputs.

Short-Term Intake of Yellowstripe Scad versus Salmon Did Not Induce Similar Effects on Lipid Profile and Inflammatory Markers among Healthy Overweight Adults despite Their Comparable EPA+DHA Content

Yellowstripe scad (YSS) have comparable eicosapentaenoic acid and docosahexaenoic acid (EPA+DHA) content to salmon. We aimed to compare the effects of YSS and salmon on lipid profile and inflammatory markers. A randomized crossover trial with two diet periods was conducted among healthy overweight (with BMI 23.0-27.4 kg/m2) Malaysian adults aged 21-55 years. Steamed whole YSS fish (≈385 g whole fish/day) or salmon fillets (≈246 g fillet/day) were given for eight weeks (3 days per week), retaining approximately 1000 mg EPA+DHA per day. Diets were switched after an 8-week washout period. Fasting blood samples were collected before and after each diet period. A total of 49 subjects participated in the intervention (35% male and 65% female; mean age 29 (7) years). YSS did not induce any significant changes in outcome measures. However, the consumption of salmon as compared with YSS was associated with reduction in triglycerides (between-group difference: -0.09 mmol/1, p = 0.01), VLDL-cholesterol (between-group difference: -0.04 mmol/1, p = 0.01), atherogenic index of plasma (between-group difference: -0.05 mmol/1, p = 0.006), and IL-6 (between-group difference: -0.01 pg/mL, p = 0.03). Despite their comparable EPA+DHA content, short-term consumption of salmon but not YSS induced significant changes in lipid profile and inflammatory markers. Larger clinical trials are needed to confirm the findings.

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

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

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.

Omega-3 Fatty Acids as Druggable Therapeutics for Neurodegenerative Disorders

Neurodegenerative disorders are commonly associated with a complex pattern of pathophysiological hallmarks, including increased oxidative stress and neuroinflammation, which makes their treatment challenging. Omega-3 Fatty Acids (O3FA) are natural products with reported neuroprotective, anti-inflammatory, and antioxidant effects. These effects have been attributed to their incorporation into neuronal membranes or through the activation of intracellular or recently discovered cell-surface receptors (i.e., Free-Fatty Acid Receptors; FFAR). Molecular docking studies have investigated the roles of O3FA as agonists of FFAR and have led to the development of receptor-specific targeted agonists for therapeutic purposes. Moreover, novel formulation strategies for targeted delivery of O3FA to the brain have supported their development as therapeutics for neurodegenerative disorders. Despite the compelling evidence of the beneficial effects of O3FA for several neuroprotective functions, they are currently only available as unregulated dietary supplements, with only a single FDA-approved prescription product, indicated for triglyceride reduction. This review highlights the relative safety and efficacy of O3FA, their drug-like properties, and their capacity to be formulated in clinically viable drug delivery systems. Interestingly, the presence of cardiac conditions such as hypertriglyceridemia is associated with brain pathophysiological hallmarks of neurodegeneration, such as neuroinflammation, thereby further suggesting potential therapeutic roles of O3FA for neurodegenerative disorders. Taken together, this review article summarizes and integrates the compelling evidence regarding the feasibility of developing O3FA and their synthetic derivatives as potential drugs for neurodegenerative disorders.

Stearic acid methyl ester affords neuroprotection and improves functional outcomes after cardiac arrest

Cardiac arrest causes neuronal damage and functional impairments that can result in learning/memory dysfunction after ischemia. We previously identified a saturated fatty acid (stearic acid methyl ester, SAME) that was released from the superior cervical ganglion (sympathetic ganglion). The function of stearic acid methyl ester is currently unknown. Here, we show that SAME can inhibit the detrimental effects of global cerebral ischemia (i.e. cardiac arrest). Treatment with SAME in the presence of asphyxial cardiac arrest (ACA) revived learning and working memory deficits. Similarly, SAME-treated hippocampal slices after oxygen-glucose deprivation inhibited neuronal cell death. Moreover, SAME afforded neuroprotection against ACA in the CA1 region of the hippocampus, reduced ionized calcium-binding adapter molecule 1 expression and inflammatory cytokines/chemokines, with restoration in mitochondria respiration. Altogether, we describe a unique and uncharted role of saturated fatty acids in the brain that may have important implications against cerebral ischemia.

Characterization of glycerophospholipid molecular species in muscles from three species of cephalopods by direct infusion-tandem mass spectrometry

More than 200 molecular species of glycerophospholipids (GP) including glycerophosphocholine (GPC), glycerophosphoethanolamine (GPE), glycerophosphoserine (GPS), lysoglycerophosphocholine (LGPC), lysoglycerophosphoethanolamine (LGPE) and lysoglycerophosphoserine (LGPS), as well as 18 kinds of sphingomyelin (SM) were characterized by using a direct infusion-tandem mass (MS/MS) spectrometry method for lipids from the muscles of cephalopods Sepiella maindroni, Octopus ocellatus and Loligo chinensis for the first time. The majority of the GP molecular species contained long-chain omega-3 polyunsaturated fatty acids (n-3 LC-PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Therefore, cephalopods can be a good possible source of dietary GP carrying n-3 LC-PUFA. The total lipids were composed of phospholipid (PL, 72.29-83.32 wt% of total lipids), cholesterol (12.70-23.60 wt% of total lipids), triacylglycerol (1.86-2.93 wt% of total lipids), diacylglycerol (0.15-1.09 wt% of total lipids), monoacylglycerol (0.06-0.18 wt% of total lipids) and free fatty acid (0.72-1.86 wt% of total lipids). For PL, phosphatidylcholine (44.47-62.30 mol%), phosphatidylethanolamine (22.57-39.08 mol%), phosphatidylserine (6.15-10.18 mol%), phosphatidylglycerol (0.68-3.11 mol%), phosphatidylinositol (2.41-7.15 mol%) and lysophosphatidylcholine (1.84-5.24 mol%) were detected. Furthermore, the total lipids from the muscles of cephalopods Sepiella maindroni, Octopus ocellatus and Loligo chinensis contained 41.80-50.02 mol% of saturated fatty acids, 11.53-21.54 mol% of monounsaturated fatty acids and 36.67-40.82 mol% of PUFA, whilst DHA (15.25-26.71 mol%) and EPA (6.29-16.57 mol%) were found to account for the majority of the PUFA. With these data presented, cephalopod muscle can be considered as a healthy food for humans.

DHA Cycling Halves the DHA Supplementation Needed to Maintain Blood and Tissue Concentrations via Higher Synthesis from ALA in Long-Evans Rats

BACKGROUND

Eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) recommendations are frequently stated at 500 mg/d; however, adherence to these recommendations would result in a large global commercial EPA/DHA production deficit. Previously, our laboratory demonstrated that acute DHA intake in rats can increase the capacity for synthesis-secretion of n-3 (ω-3) polyunsaturated fatty acids (PUFAs).

OBJECTIVE

We aimed to investigate the utility of a dietary DHA cycling strategy that employs 2 wk of repeated DHA feeding for a total of 3 cycles over 12 wk.

METHODS

Male Long-Evans rats were fed a 10% fat diet by weight comprised of either 1) a 2-wk, 2% α-linolenic acid (ALA, DHA-ALA group 18:3n-3) diet followed by a 2-wk, 2% DHA + 2% ALA diet over 3 consecutive 4-wk periods ("DHA cycling," DHA-ALA group); 2) a 2% DHA + 2% ALA diet (DHA group) for 12 wk; or 3) a 2% ALA-only diet (ALA group) for 12 wk. At 15 wk old, blood and tissue fatty acid concentrations and liver mRNA expression and 13C-DHA natural abundances were determined.

RESULTS

DHA concentrations in plasma, erythrocytes, and whole blood between the DHA-ALA group and the DHA groups were not different (P ≥ 0.05), but were 72-110% higher (P < 0.05) than in the ALA group. Similarly, DHA concentrations in liver, heart, adipose, and brain were not different (P ≥ 0.05) between the DHA-fed groups, but were at least 62%, 72%, 320%, and 68% higher (P < 0.05) than in the ALA group in liver, heart, adipose, and skeletal muscle, respectively. Compound-specific isotope analysis indicated that 310% more liver DHA in the DHA-ALA group compared with the DHA group is derived from dietary ALA, and this was accompanied by a 123% and 93% higher expression of elongation of very long-chain (Elovl)2 and Elovl5, respectively, in the DHA-ALA group compared with the ALA group.

CONCLUSIONS

DHA cycling requires half the dietary DHA while achieving equal blood and tissue DHA concentrations in rats. Implementation of such dietary strategies in humans could reduce the gap between global dietary n-3 PUFA recommendations and commercial production.

How does high DHA fish oil affect health? A systematic review of evidence

The health benefits of fish oil, and its omega-3 long chain polyunsaturated fatty acid content, have attracted much scientific attention in the last four decades. Fish oils that contain higher amounts of eicosapentaenoic acid (EPA; 20:5n-3) than docosahexaenoic acid (DHA; 22:6n-3), in a distinctive ratio of 18/12, are typically the most abundantly available and are commonly studied. Although the two fatty acids have traditionally been considered together, as though they were one entity, different physiological effects of EPA and DHA have recently been reported. New oils containing a higher quantity of DHA compared with EPA, such as fractionated and concentrated fish oil, tuna oil, calamari oil and microalgae oil, are increasingly becoming available on the market, and other oils, including those extracted from genetically modified oilseed crops, soon to come. This systematic review focuses on the effects of high DHA fish oils on various human health conditions, such as the heart and cardiovascular system, the brain and visual function, inflammation and immune function and growth/Body Mass Index. Although inconclusive results were reported in several instances, and inconsistent outcomes observed in others, current data provides substantiated evidence in support of DHA being a beneficial bioactive compound for heart, cardiovascular and brain function, with different, and at times complementary, effects compared with EPA. DHA has also been reported to be effective in slowing the rate of cognitive decline, while its possible effects on depression disorders are still unclear. Interestingly, gender- and age- specific divergent roles for DHA have also been reported. This review provides a comprehensive collection of evidence and a critical summary of the documented physiological effects of high DHA fish oils for human health.

Changes in Bioavailability of Omega-3 (DHA) through Alpha-Tocopheryl Phosphate Mixture (TPM) after Oral Administration in Rats

Benefits of Omega-3 Docosahexaenoic acid (DHA) supplements are hindered by their poor solubility and bioavailability. This study investigated the bioavailability of various formulations of Omega-3 and tocopheryl phosphate mixture (TPM), following oral administration in rats, and assessed whether TPM could improve the oral absorption of DHA. The rats were administered with a high (265.7 mg/kg) or low dose (88.6 mg/kg) of DHA. TPM was examined at 1:0.1 w/w (low TPM dose) and 1:0.5 w/w (high TPM dose). Over 24 h, the DHA plasma concentration followed a TPM dose-dependent relationship, reflected in the higher mean Cmax values (78.39 and 91.95 μg/mL) and AUC values (1396.60 and 1560.60) for the low and high TPM, respectively. The biggest difference between the low dose DHA control (LDCont) and TPM formulations was at 4 h after supplementation, where the low and high TPM showed a mean 20% (ns) and 50% (p < 0.05) increase in DHA plasma concentrations versus the control formulation. After correcting for baseline endogenous DHA, the mean plasma DHA at 4 h produced by the LD-HTPM was nearly double (90%) the LDC control (p = 0.057). This study demonstrated that co-administering omega-3 with TPM significantly increases the bioavailability of DHA in the plasma, suggesting potential use for commercially available TPM + DHA fortified products.

Forms of n-3 (ALA, C18:3n-3 or DHA, C22:6n-3) Fatty Acids Affect Carcass Yield, Blood Lipids, Muscle n-3 Fatty Acids and Liver Gene Expression in Lambs

The effects of supplementing diets with n-3 alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA) on plasma metabolites, carcass yield, muscle n-3 fatty acids and liver messenger RNA (mRNA) in lambs were investigated. Lambs (n = 120) were stratified to 12 groups based on body weight (35 ± 3.1 kg), and within groups randomly allocated to four dietary treatments: basal diet (BAS), BAS with 10.7 % flaxseed supplement (Flax), BAS with 1.8 % algae supplement (DHA), BAS with Flax and DHA (FlaxDHA). Lambs were fed for 56 days. Blood samples were collected on day 0 and day 56, and plasma analysed for insulin and lipids. Lambs were slaughtered, and carcass traits measured. At 30 min and 24 h, liver and muscle samples, respectively, were collected for determination of mRNA (FADS1, FADS2, CPT1A, ACOX1) and fatty acid composition. Lambs fed Flax had higher plasma triacylglycerol, body weight, body fat and carcass yield compared with the BAS group (P < 0.001). DHA supplementation increased carcass yield and muscle DHA while lowering plasma insulin compared with the BAS diet (P < 0.01). Flax treatment increased (P < 0.001) muscle ALA concentration, while DHA treatment increased (P < 0.001) muscle DHA concentration. Liver mRNA FADS2 was higher and CPT1A lower in the DHA group (P < 0.05). The FlaxDHA diet had additive effects, including higher FADS1 and ACOX1 mRNA than for the Flax or DHA diet. In summary, supplementation with ALA or DHA modulated plasma metabolites, muscle DHA, body fat and liver gene expression differently.