Something about the fish oil industry is fishy, and it is not just the oil. Fish oil supplements have been a trusted staple in the medicine cabinets of many Americans since the late 1980s. In 2012, a meta-analysis of twenty studies published in the Journal of the American Medical Association (JAMA) examined the effects of omega-3 supplements, like fish oils from salmon or cod, on the risk of heart attacks, strokes, and overall mortality related to heart disease. Despite the popularity of fish oil supplements, researchers found no statistical evidence that suggests they reduce an individual’s risk of heart disease, heart attacks, or strokes.
The JAMA meta-analysis began by analyzing the first Diet and Reinfarction Trial (DART1) from 1989. In this study, patients who had suffered a heart attack ate fatty fish (two to three portions a week) for two years. The DART1 trial astounded researchers with a 29% reduction in the two-year overall heart disease mortality in the group consuming fatty fish. The success of this trial was attributed to the polyunsaturated omega-3 fatty acids (PUFA) found in fatty fish. Omega-3 fatty acids were hypothesized to lower triglycerides in the blood that contribute to heart disease. With these results in mind, the medical community was determined to incorporate more omega-3 fatty acids into the diets of cardiovascular patients across America. Fish oil supplements were a cheap, convenient way for patients to incorporate omega-3 fatty acids into their diets, without the expense or hassle of cooking fish.
This meta-analysis also included the second DART trial (DART2). DART2 incorporated fish oil supplements as a source of omega-3 fatty acids. The DART2 trial found no evidence to support that fish oil supplements prevent heart disease, heart attacks, or strokes. By this time in 2003, fish oil supplements were already generating millions of dollars from heart-conscious consumers. After reviewing over twenty studies on the efficacy of fish oil supplements, the meta-analysis by the JAMA concluded that these fish oil supplement were not effective primary or secondary intervention methods for preventing heart disease or complications, such as heart attacks or strokes. Simply adding a fish oil supplement to the diet does not counteract other diet and lifestyle choices, like smoking or lack of exercise, that contribute to heart disease. Patients seeking to reduce their risk for heart disease may find more success from regular exercise and heart-healthy diets instead of dietary supplements.