You probably heard about the results of a British analysis concluding that there’s no solid proof that omega 3 fish oil found in salmon and other cold water fish prevent heart disease. A team of researchers reviewed the findings of 89 studies on how omega 3 intake affects the risk of heart disease, cancer and stroke and published their findings in the March 25, 2006, issue of the British Medical Journal. They concluded that the evidence is "mixed."
The problem with this analysis is that it included studies of people using omega fish oil who had existing cardiac problems along with studies of people who did not. This makes it difficult to draw any conclusion, except that we need more and better studies with omega 3s.
While the benefits of omega 3 fish oil for healthy people aren’t certain, for those who already have heart disease, they look pretty good. And we know that populations that eat fish regularly live longer and have less chronic disease than populations that do not. (We don’t know if this is because fish displaces meat or because it has positive attributes of its own. Certainly, fish provides high-quality protein without the saturated fat present in meat and poultry.)
Despite the fact that we don’t yet have incontrovertible proof of the benefits of omega 3s, most health experts in the United States recommend increasing consumption of omega 3 fish oil found in oily fish such as salmon, sardines, and herring or taking supplemental fish oil. My longstanding recommendation is to consume two to three servings of fish per week. The American Heart Association recommends eating at least two fish meals a week.
To prove beyond doubt that omega 3 fish oil prevents heart disease and other medical problems in healthy people we would need more and bigger studies of longer duration. Unfortunately, such studies are very expensive and, to my knowledge, none has yet been launched.
What I do know is that including oily fish in the diet (or taking fish oil supplements) is particularly beneficial if you have high cholesterol, diabetes, symptoms of PMS, coronary artery disease, breast cancer, memory loss, depression, insulin resistance, high cholesterol or rheumatoid arthritis.
Andrew Weil, M.D.