A recently published systematic review and meta-analysis 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 [JAMA. 2012;308(10):
A meta-analysis is a statistical method that combines the results from several randomized clinical trials (RCTs) that address similar questions. 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 PUFA administration with a combined total of 68,680 patients.
An emerging theme from the JAMA study as well as several other reviews on this topic is that omega-3 supplementation appears to be more effective at prevention (“primary prevention”) than therapy (“secondary prevention”) of cardiovascular diseases (CVD). 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, anti-hypertensive medications). However, 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 (see the article in the Micronutrient Information Center). Omega-3 PUFAs can be obtained from both food and supplemental sources. If you do not regularly consume fish, the LPI recommends a two-gram fish oil supplement several times per week (see the LPI's Prescription for Health). 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. More extensive information on this important topic will be published in our 2012 Fall/Winter Newsletter.