Omega-3 Fish Oil Supplements: Beneficial, Harmful or Waste of Money?October 12, 2018 /
Anne Danahy, MS, RDN
Omega-3 fish oil supplements are one of the most popular nutritional supplements in the US. A 2015 National Institutes of Health survey found that approximately 7.8%, or 18.8 million adults, take the supplement,1 which is frequently recommended for heart health. Although research supports various health benefits from eating fish several times each week, the latest findings on omega-3 fish oil supplements are mixed. Should RDs be recommending fish oil supplements? And if so, who might benefit and how should they be used?
The latest research on cardiovascular health
Because observational studies have suggested that eating more fish appears to reduce the risk of cardiovascular disease (CVD), omega-3 fish oil supplements are frequently recommended for those at risk, and especially for those who do not consume the recommended 2 servings of fish per week. Unfortunately, several recent research reviews on the potential benefits of supplements is not as convincing as older studies.
Results of a systematic review, conducted by Balk et al, on the effect of omega-3 fatty acids and CVD showed that while higher doses of omega-3 fatty acids can influence lipid levels by reducing triglycerides, increasing high density lipoprotein (HDL)-cholesterol, and improving total cholesterol to HDL ratios, there was no association between omega-3 supplements and heart attack or stroke.2 The researchers also noted that omega-3 supplements can increase low density lipoprotein (LDL)-cholesterol, along with the increase in HDL. While other studies have shown a benefit for blood pressure, this review found none.2
A 2018 meta-analysis by Aung et al on 10 studies that involved nearly 78,000 at-risk individuals found similar results—no significant association with fatal or nonfatal coronary heart disease or any major vascular events.3 Each of the studies examined had a least 500 subjects and the mean follow up time was 4.4 years. Aung et al also looked at individual subgroups such as sex, history of heart disease, diabetes, lipid levels and prior use of statins. It should be noted that most of the individual studies used low doses (approximately 1-2 grams/day) of omega-3 supplements. In their concluding statement, the authors stated that more research is needed to determine if higher doses of omega-3 (3-4g/day) are beneficial.3
Although the latest European Society of Cardiology and European Atherosclerosis Society guidelines for prevention of CVD both cast doubt on the usefulness of omega-3 supplements, the American Heart Association still recommends them for one group in particular – those who have a known history of coronary heart disease, or heart failure.4
In 2017, the American Heart Association revised their 2002 statement that recommended omega-3 supplements for the public, as part of a CVD risk-reducing strategy.4 They agree that there is insufficient evidence to support this recommendation for the public, including those with diabetes and prediabetes. However, they still feel there is enough evidence to recommend omega-3 supplements for those with coronary heart disease, previous heart attack, or heart failure as they may reduce mortality and hospitalizations by 10% and 9% respectively.4
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