I was watching my usual TV news channels when a story was presented citing a recent study from the Fred Hutchinson Cancer Reseach Center in Seattle and published on-line in the Journal of the National Cancer Institute. The study results seemed to conclude that taking fish oil supplements or eating too much fatty fish, thereby producing higher serum levels of omega-3 fatty acids, may be linked to an increased risk of prostate cancer. Every TV news story included commentary from the news organization’s resident “medical expert” who unanimously concluded that they would now recommend limiting a man’s input of fish oil and fish itself even though health benefits from essential fats like the omega-3 fatty acids from fish and fish oil and the omega-6 fatty acids from olive oil etc. are well known. However, the benefits of excessive omega-3 supplementation was now being called into question. While fish oil does indeed have an anti-inflammatory effect, the study researchers could not offer a biological reason for this link with prostate cancer and called for more studies. The study analyzed levels of omega-3 fatty acids found to a larger degree in some fish in the blood levels of 834 men who had developed prostate cancer and compared these blood levels to 1,393 men with respect to age and race who had not developed cancer. Men who had the highest levels of omega-3 fatty acids had a 43% increase in risk for prostate cancer and a 71% increase in risk for high-grade prostate cancer most likely to be fatal. The highest blood levels of three omega-3 fatty acids (EPA, DPA and DHA) were consistent with taking fish oil supplements or eating at least three servings of fish per week. The men with the highest levels were the most likely to eventually be diagnosed with prostate cancer. These studies are far from clear and a biological basis for these findings is being sought. Earlier, similar studies in a large trial called SELECT had found that taking vitamin E supplements actually increased the risk for prostate cancer. There is another side to this story which did not appear on my TV news channels. The Prostate Cancer Research Institute (PCRI) recently summarized the comments of three well-known prostate cancer researcher-physicians who unanimously differed in their interpretation of these study results. The physicians include Dr. Anthony D’Amico of Harvard and Brigham and Women’s Hospital in Boston, Dr. Mark Moyad and Dr. Charles Myers. The accompanying link also contains a summary of the original study as well as the physicians’ specific comments and critiques. I suggest that you read their comments, and discuss them with your personal prostate cancer physician before making any changes in your dietary and nutritional habits. The opposing viewpoints were not presented on any of the major news channels to my viewing knowledge.
As a naturopathic urologist who primarily deals with prostate cancer – I find this study to be highly flawed with most better designed studies showing the protective aspects of fish oils. If people stop taking fish based on this study they are doing a major disservice to themselves.