Tuesday’s meta-analysis in JAMA concluding that omega-3s may not benefit heart health has been widely disputed by industry experts. In this special focus, NutraIngredients-USA revisits our recent coverage of other omega-3 meta-analyses that found significant benefits for the fatty acids.
First up is the meta-analysis by scientists from Brigham and Women's Hospital and Harvard University in Boston that found that increased intakes of omega-3s and higher blood levels of the fatty acids are associated with a 15% decrease in the risk of heart failure.
Seven prospective studies, which provided data on 176,441 subjects and 5,480 incident cases of heart failure, indicated that people with the highest category of EPA and DHA levels had a 14% lower risk of heart failure, compared to people with the lowest levels.
Commenting on the potential mechanism, the researchers noted that EPA and DHA and fish have been linked to lower levels of triglycerides and improved blood lipid levels, which could favorably influence the heart failure risk. In addition, EPA and DHA have been reported to improved ventricular function, heart rate, and inflammation, they said (Clinical Nutrition, doi: 10.1016/j.clnu.2012.05.010).
Please click here to read: Omega-3s may lower heart failure risk by 15%: Meta-analysis
In March, scientists from the Chinese Academy of Medical Sciences & Peking Union Medical College reported that supplements of omega-3 fatty acids may improve the function of blood vessels and support vascular health.
A new meta-analysis of 16 studies found that daily supplements of omega-3s for an average of 56 days were associated with a 2.3% improvement in flow-mediated dilation (FMD), a measure of a blood vessel's healthy ability to relax, according to findings published in Atherosclerosis (Vol. 221, pp. 536-543).
Please click here to read: Omega-3s may improve health of blood vessels: Meta-analysis
Scientists from Harvard and the Cleveland Clinic reported in the Journal of Nutrition that algae-derived docosahexaenoic acid (DHA) supplementation may boost levels of HDL (good) cholesterol and cut levels of triglycerides.
The scientists also reported that supplemental DHA is associated with an increase in LDL cholesterol. While LDL is seen by many as ‘bad’ cholesterol and that any increase is detrimental, the reviewers note that the data indicated an increase in the size of the particles.
“Because particle size, in addition to lipoprotein cholesterol content, may help predict atherogenic risk, the net effect of algal DHA supplementation on serum lipoproteins and lipids may be beneficial despite the increase in LDL-cholesterol,” they wrote.
Please click here to read: Harvard meta-analysis supports benefits of algal DHA omega-3
To finish, two studies in the American Journal of Clinical Nutrition indicated that increased intakes of omega-3 fatty acids may reduce a specific marker of inflammation and confer heart and anti-cancer benefits.
The studies focus on the effects of omega-3 on levels of inflammatory biomarkers that are involved in damage to cells called soluble adhesion molecules, particularly soluble intercellular adhesion molecule-1 (sICAM-1). It is generally accepted that low circulating level of sICAM-1 is good.
The first of the two new studies is a meta-analysis by Yang et al.from the Bethune First Hospital of Jilin University in China. The analysis indicated that omega-3 supplements were associated with reduced levels of sICAM-1, which may contribute to a decrease in the risk of atherosclerosis.
The second study, by Touvier et al. from the National Institute of Health and Medical Research in Paris, indicated that increased levels of omega-3 may counteract the pro-carcinogenic action of sICAM-1.
Please click here to read: Omega-3 may reduce inflammatory marker to offer ‘multiple’ health benefits