Fish oils are a popular supplement due to their anti-inflammatory effects and cardiovascular benefits. Evidence suggests they help reduce triglycleride levels, lower blood pressure, and help prevent heart disease ands stroke. Millions of American take these supplements on a daily basis.
Despite the health benefits of fish oils, a new study published in the Journal of the National Cancer Institute links the intake of fish oil to prostate cancer. The study looked at the levels of omega-3 fatty acids in blood and discovered that men with higher levels of omega-3 fatty acids had a 43% increased risk of developing prostate cancer.
It is important to remember that this is one study that has many flaws. First, the researchers did not look at the dietary intake of fish or omega-3 supplements; they only looked at the results of a blood test. Second, this was one physiological marker at a single point in time and it cannot prove causation. Third, this study conflicts with many other studies that found a protective benefit from fish oils and prostate cancer. Lastly, the subjects of the study had many other risk factors related to prostate cancer; for example, over half the subjects were smokers and over 3/4 of the subjects were obese.
It would be premature to stop taking fish oil supplements based on this study, and the health benefits of omega 3 fatty acids seem to outweigh the possible potential risks of the supplement.