If you are keeping up with the current news, you may be aware that an article came out recently that suggests there is link between elevated plasma omega-3 fatty acid levels and an increased risk of prostate cancer (Journal of the National Cancer Institute – July 2013).
Naturally, the media circulated many headlines telling the general public that "fish oils may raise prostate cancer risks, study confirms." Allow me to clarify a few important notes for you regarding this study. You know me well enough by now to know that health has to make common sense! So does research …
a) One might assume that this study occurred to evaluate the risk of prostate cancer in men taking fish oil supplements. It did not. In fact, the study did not even look at fish oil supplements in any of their participants! The initial intended treatments were Selenium and Vitamin E. There is no documentation of fish oil or dietary fish intake at the beginning, middle, or end of the study. One can not draw conclusions about supplement use when the question was never even asked or documented.
b) Also of concern were the comments made by the lead researcher in a press release quoted as saying "We've shown once again that use of nutritional supplements may be harmful," hinting at a strong bias of the researchers themselves.
c) The measure taken of omega 3 's in the blood was done by "plasma phospholipid levels" which are not a good long term marker of omega 3 levels at all – the levels can vary dramatically within a 48 hour period based on meal or supplement consumption . In my office, I would rarely use this type of test because it's too narrow. It views one moment in time. I order the "erythrocyte" method of testing because it gives a better long-term picture.
d) The increased prostate cancer risks they ascribe to men who consume large amounts of omega-3 is based on a level of 4.66% in the cancer group, versus a level of 4.48% in the control group.
Formulating nutritional products of the highest efficacy requires impeccable solid research. It seems clear the researchers from this study extrapolated the findings far beyond what the data could support and failed to supply adequate context around their findings.
Thousands of legitimate studies over the past 30 years have been published supporting the many benefits of omega-3's. There have been over 10,000 studies done and fish oils are the most widely studied nutritional supplement. Here are some resources I would encourage you to explore:
For Responsible Nutrition Council – A Leading nutritional organization's response
Organization for EPA Global and DHA Omega-3 (GOED) , Rapid Review News Alert