expert opinion

Do fatty fish and fish oil supplements have the same health-promoting effects?

December 15, 2012

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Linus Pauling Institute, Oregon State University, Corvallis, Oregon, USA

“Recently published systematic reviews and meta-analyses concluded that supplementation with omega-3 polyunsaturated fatty acids (PUFAs), often referred to as fish oils, is not associated with a statistically significant reduction in risk of major cardiovascular events (1,2). In the present analyses, the authors pooled data from several randomized controlled trials (RCTs), investigating the potential link between the consumption of fish or fish oil supplements and major cardiovascular disease (CVD) events. Combining multiple trials in a meta-analysis increases the pro-bability of detecting participant group differences if present. However, selection criteria for including or exclu-ding studies can strongly influence the results of the meta-analysis and represent an important methodolo-gical limitation. In the present analysis, the authors pooled data on major cardiovascular events (all-cause mortality, cardiac death, sudden death, myocardial infarction, and stroke) from 20 RCTs of omega-3 fatty acids administration with a combined total of 68,680 patients.

Notably, the vast majority of the pooled RCTs were secondary prevention trials, meaning that the recruited subjects had pre-existing CVD or were at increased cardiovascular risk. Thus, supplementation with omega-3 PUFAs may not reduce the risk of cardiovascular events in patients with a history of CVD, particularly when used in combination with drug therapy (e.g., statins, aspirin, and anti-hypertensive medications). Several other reviews on this topic have indicated that omega-3 supplementation appears to be more effective at prevention (“@@primary prevention”) than therapy (“ secondary prevention ”) of CVD.

Observational epidemiologic studies have consistently found that increased fish consumption or higher omega-3 PUFA blood levels are associated with a significantly lower risk of cardiovascular events in healthy adults. Beyond cardiovascular health, fish oils are important for visual and neurological development, exert anti-inflammatory effects, and may slow cognitive decline with aging. Omega-3 PUFAs can be obtained from both food and supplemental sources. If you do not regularly consume fish, the Linus Pauling Institute recom-mends a two-gram fish oil supplement several times per week. Consumption of fish or fish oil may not be suitable for all individuals, such as vegetarians, vegans, or individuals with seafood allergies. Alternative sources of omega-3 fatty acids, produced in yeast or algae are commercially available.”

Based on: Linus Pauling Institute. LPI’s Response to a Recent Review on Omega-3 Polyunsaturated Fatty Acids and Cardiovascular Disease Risk. Published online November 2012.

References

  1. Chowdhury R. et al. Association between fish consumption, long chain omega 3 fatty acids, and risk of cerebrovascular disease: systematic review and meta-analysis. British Medical Journal. Published online October 2012.
  2. Rizos E. C. et al. Association between omega-3 fatty acid supplementation and risk of major cardiovas-cular disease events: a systematic review and meta-analysis. JAMA. 2012; 308(10):1024-1033.