A combination of omega-3 fatty acids, folic acid and B-group vitamins is superior at lowering homocysteine than omega-3 alone: a meta-analysis

The aim of the study was to assess whether omega-3 polyunsaturated fatty acid supplementation alone or in combination with folic acid and B-group vitamins is effective in lowering homocysteine. The Medline Ovid, Embase and Cochrane databases were searched for randomized-controlled trial studies that intervened with omega-3 supplementation (with or without folic acid) and measured changes in homocysteine concentration. Studies were pooled using a random effects model for meta-analysis. Three different models were analyzed: all trials combined, omega-3 polyunsaturated fatty acid trials, and omega-3 polyunsaturated fatty acids with folic acid and B-group vitamin trials. Nineteen studies were included, consisting of 3267 participants completing 21 trials. Studies were heterogeneous; varying by dose, duration and participant health conditions. Across all trials, omega-3 supplementation was effective in lowering homocysteine by an average of 1.18μmol/L (95%CI: (-1.89, -0.48), P=.001). The average homocysteine-lowering effect was greater when omega-3 supplementation was combined with folic acid and B-group vitamins (-1.37μmol/L, 95%CI: (-2.38, -0.36), P<.01) compared to omega-3 supplementation alone (-1.09μmol/L 95%CI: (-2.04, -0.13), P=.03). Omega-3 polyunsaturated fatty acid supplementation was associated with a modest reduction in homocysteine. For the purposes of reducing homocysteine, a combination of omega-3s (0.2-6g/day), folic acid (150 - 2500μg/day) and vitamins B6 and B12 may be more effective than omega-3 supplementation alone.

Microencapsulation of omega-3 fatty acids: a review of microencapsulation and characterization methods

To improve consumption of omega-3 fatty acids, foods can be enriched with omega-3 rich oils. Microencapsulation of omega-3 oils minimizes oxidative deterioration and allows their use in stable and easy-to-handle form. Microencapsulation of omega-3 fatty acids can be achieved by using a variety of methods, with the two most commonly used commercial processes being complex coacervation and spray dried emulsions. A variety of other methods are in development including spray chilling, extrusion coating and liposome entrapment. The key parameter in any of these processes is the selection of wall material. For spray dried emulsions and complex coacervates protein or polysaccharides are primarily used as shell material, although complex coacervation is currently commercially limited to gelatin. Here we review the need for microencapsulation of omega-3 oils, methods of microencapsulation and analysis, and the selection of shell material components. In particular, we discuss the method of complex coacervation, including its benefits and limitations. This review highlights the need for research on the fundamentals of interfacial and complexation behaviour of various proteins, gums and polyphenols to encapsulate and deliver omega-3 fatty acids, particularly with regard to broadening the range of shell materials that can be used in complex coacervation of omega-3 rich oils.

Marine omega-3 fatty acids and coronary heart disease

Purpose of review: To provide an overview of the key earlier intervention studies with marine omega-3 fatty acids and to review and comment on recent studies reporting on mortality outcomes and on selected underlying mechanisms of action. Recent findings: Studies relating marine omega-3 fatty acid status to current or future outcomes continue to indicate benefits, for example, on incident heart failure, congestive heart failure, acute coronary syndrome, and all-cause mortality. New mechanistic insights into the actions of marine omega-3 fatty acids have been gained. Three fairly large secondary prevention trials have not confirmed the previously reported benefit of marine omega-3 fatty acids towards mortality in survivors of myocardial infarction. Studies of marine omega-3 fatty acids in atrial fibrillation and in cardiac surgery-induced atrial fibrillation have produced inconsistent findings and meta-analyses demonstrate no benefit. A study confirmed that marine omega-3 fatty acids reduce the inflammatory burden with advanced atherosclerotic plaques, so inducing greater stability. Summary: Recent studies of marine omega-3 fatty acids on morbidity of, and mortality from, coronary and cardiovascular disease have produced mixed findings. These studies raise new issues to be addressed in future research.

Postprandial enrichment of triacylglycerol-rich lipoproteins with omega-3 fatty acids: lack of an interaction with apolipoprotein E genotype?

Background: We have previously demonstrated that carrying the apolipoprotein (apo) E epsilon 4 (E4+) genotype disrupts omega-3 fatty acids (n − 3 PUFA) metabolism. Here we hypothesise that the postprandial clearance of n − 3 PUFA from the circulation is faster in E4+ compared to non-carriers (E4−). The objective of the study was to investigate the fasted and postprandial fatty acid (FA) profile of triacylglycerol-rich lipoprotein (TRL) fractions: Sf >400 (predominately chylomicron CM), Sf 60 − 400 (VLDL1), and Sf 20 − 60 (VLDL2) according to APOE genotype. Methods: Postprandial TRL fractions were obtained in 11 E4+ (ε3/ε4) and 12 E4− (ε3/ε3) male from the SATgenε study following high saturated fat diet + 3.45 g/d of docosahexaenoic acid (DHA) for 8-wk. Blood samples were taken at fasting and 5-h after consuming a test-meal representative of the dietary intervention. FA were characterized by gas chromatography. Results: At fasting, there was a 2-fold higher ratio of eicosapentaenoic acid (EPA) to arachidonic acid (P = 0.046) as well as a trend towards higher relative% of EPA (P=0.063) in theSf >400 fraction of E4+. Total n − 3 PUFA in the Sf 60 − 400 and Sf 20 − 60 fractions were not APOE genotype dependant. At 5 h, there was a trend towards a time × genotype interaction (P=0.081) for EPA in theSf >400 fraction. When sub-groups were form based on the level of EPA at baseline within the Sf >400 fraction, postprandial EPA (%) was significantly reduced only in the high-EPA group. EPA at baseline significantly predicted the postprandial response in EPA only in E4+ subjects (R2 = 0.816). Conclusion: Despite the DHA supplement contain very low levels of EPA, E4+ subjects with high EPA at fasting potentially have disrupted postprandial n − 3 PUFA metabolism after receiving a high-dose of DHA. Trial registration: Registered at clinicaltrials.gov/show/NCT01544855.

Dietary omega 3 fatty acids decrease intraocular pressure with age by increasing Aqueous outflow

Purpose: To determine whether there is an association between dietary omega-3 (ω-3) fatty acid intake, age, and intraocular pressure (IOP) caused by altered aqueous outflow. Methods: Sprague–Dawley rats were fed either ω-3–sufficient (ω-3⁺) or ω-3–deficient (ω-3^–) diets from conception. The diets had 7% lipid content. The ω-3⁺ diet contained safflower, flaxseed, and tuna oils (5.5:1.0:0.5), and the ω-3^– diet contained safflower oil only. Intraocular pressure was measured at 5 to 40 weeks of age under light anesthesia (ω-3⁺, n = 39; ω-3^–, n = 48). Aqueous outflow was determined at 45 weeks in a subgroup of animals (ω-3⁺, n = 15;ω-3^–, n = 22) using pulsed infusion. Ciliary body tissues (n = 6 per group) were assayed for fatty acid content by thin-layer and gas-liquid chromatography in both diet groups. Results: Animals raised on ω-3⁺ diets had a 13% decrease in IOP at 40 weeks of age (13.48 ± 0.32 mm Hg vs. 15.46 ± 0.29 mm Hg; P < 0.01). When considered as a change in IOP relative to 5 weeks of age, the ω-3⁺ group showed a 23% decrease (P < 0.001). This lower IOP in the ω-3⁺ diet group was associated with a significant increase (+56%; P < 0.001) in outflow facility and a decrease in ocular rigidity (–59%; P < 0.001). The ω-3⁺ group showed a 3.3 times increase in ciliary body docosahexaenoic acid (P < 0.001). Conclusions: Increasing dietary ω-3 reduces IOP with age because of increased outflow facility, likely resulting from an increase in docosanoids. This indicates that dietary manipulation may provide a modifiable factor for IOP regulation. However, further studies are needed to consider whether this can modify the risk for glaucoma and can play a role in treatment of the disease.

Effect of feeding systems on omega-3 fatty acids, conjugated linoleic acid and trans fatty acids in Australian beef cuts: potential impact on humnan health

The influence of feeding systems on the levels of functional lipids and other fatty acid concentrations in Australian beef was examined. Rump, strip loin and blade cuts obtained from grass feeding, short-term grain feeding (80 days; STGF) and long-term grain feedlot rations (150-200 days; LTFL) were used in the present study. The typical Australian feedlot ration contains more than 50% barley and/or sorghum and balanced with whole cottonseed and protein meals were used as feed for STGF and LTFL regimens. Meat cuts from 18 cattle for each feeding regimen were trimmed of visible fat and  connective tissue and then minced (300 g lean beef); replicate samples of 7g were used for fatty acid (FA) analysis. There was a significantly higher level of total omega-3 (n-3) and long chain n-3 FA in grass-fed beef (P <0.0001) than the grain-fed groups regardless of cut types. Cuts from STGF beef had significantly reduced levels of n-3 FA and conjugated linoleic acid (CLA) and similar levels of saturated, monounsaturated and n-6 FA compared with grass feeding (P <0.001). Cuts from LTFL beef had higher levels of saturated, monounsaturated, n-6 FA and trans 18:1 than similar  cuts from the other two groups (P <0.01), indicating that increased length of grain feeding was associated with more fat deposited in the carcass. There was a step-wise increase in trans 18:1 content from grass to STGF to LTGF, suggesting grain feeding elevates trans FA in beef, probably because of increased intake of 18:2n-6. Only grass-fed beef reached the target of more than 30mg of long chain n-3 FA/100 g muscle as recommended by Food Standard Australia and New Zealand for a food to be considered a source of omega- 3 fatty acids. The proportions of trans 18:1 and n-6 FA were higher (P<0.001) for both grain-fed beef groups than grass-fed beef. Data from the present study show that grain feeding decreases functional lipid  components (long chain n-3 FA and CLA) in Australian beef regardless of meat cuts, while increasing total trans 18:1 and saturated FA levels.

Production and bioavailability of calcium and magnesium salts of omega-3 fatty acids

In order to provide an alternative to traditional liquid fish oil gelatin capsules, we developed a solid, powdered form of omega-3 fish oil concentrate by forming calcium- and magnesium-fatty acid salts. These salts were produced using a concentrated fish oil ethyl ester that contained in excess of 60% omega-3 fatty acids. The bioavailability of these omega-3 salts was compared with that of fish oil ethyl ester in mice. Animals were given 8 mg of omega-3 fatty acid ethyl ester concentrate (control), calcium- or magnesium-omega-3 salts daily for three weeks. The omega-3 salt products resulted in omega-3 fatty acid content in serum and red blood cell membranes comparable to that produced by the ethyl ester supplementation. In addition, fecal excretion of omega-3 fatty acids was not increased by the presence of calcium or magnesium. In fact, there was a tendency for less omega-3 fatty acids to be excreted.