The recent news is unavoidable, Omega-3 Fatty Acids, usually used by men with heart ailments and prostate cancer is tied to a 71% increase of developing prostate cancer and that the cancer is often an aggressive prostate cancer!

A prospective study by scientists at Fred Hutchinson Cancer Research Center has confirmed the link between high blood concentrations of omega-3 fatty acids and an increased risk of prostate cancer. The study, which was published July 11 in the online edition of the Journal of the National Cancer Institute indicates that high concentrations of EPA, DPA and DHA, the three anti-inflammatory and metabolically related fatty acids derived from fatty fish and fish-oil supplements are associated with a 71 percent increased risk of high-grade prostate cancer. The study also found a 44 percent increase in the risk of low-grade prostate cancer and an overall 43 percent increase in risk for all prostate cancers.

The findings of this current study confirm a 2011 study also published by the same scientific team where they reported that a similar link between high blood concentrations of DHA and a more than doubling of the risk for developing high-grade prostate cancer. Additionally, this study confirms similar results from a large European study.

According to Alan Kristal, P.H.D., the paper’s senior author and member of the Fred Hutch Public Health Sciences Division “The consistency of these findings suggests that these fatty acids are involved in prostate tumor genesis and recommendations to increase long-chain omega-3 fatty acid intake, in particular through supplementation, should consider with potential risks, …. We’ve shown once again that use of nutritional supplements may be harmful…”

Dr. Kristal in another recent analysis published in the Journal of the American Medical Association questioned the benefit of omega-3 supplementation for cardiovascular diseases. The analysis, which combined the data from 20 studies, found no reduction in all-cause mortality, heart attacks or strokes.

Most researchers and clinicians have expressed surprise at these findings. Omega-3 fatty acids are believed to offer many positive health effects based on their anti-inflammatory properties. We do know that Inflammation plays a role in the development and growth of many cancers, including prostate cancer. Given this it is perplexing to us why high levels of omega-3 fatty acids would increase prostate cancer risk, especially high risk prostate cancers.

In trying to understand these results it has been mentioned that possibly the harmful effect of omega-3 fatty acids comes from their conversion into compounds that can cause damage to cells and DNA, and their role in immunosuppression.

In analyzing the results of this study we find that the difference in blood concentrations of omega-3 fatty acids between the lowest and highest risk groups was about 2.5 percentage points (3.2 percent vs. 5.7 percent). This difference is larger than the effect of eating salmon twice a week, Kristal said.

This study was a retrospective study of data derived from men who participated in the Selenium and Vitamin E Cancer Prevention Trial (SELECT). This study was a large randomized, placebo-controlled trial looking at whether selenium and vitamin E, either alone or combined, reduced prostate cancer risk. That study showed no benefit from selenium intake and an increase in prostate cancers in men who took vitamin E.

In trying to understand the actual meaning of these results for us as survivors of advanced prostate cancer, we need to remember that there has not been an evidence of a cause and effect, or there isn’t any evidence that the higher levels of omega-3 fatty acids caused prostate cancer or more aggressive advanced prostate cancer. However, it still remains a good idea to limit our intake of omega-3 fatty acids to 2 to 3 helpings of fatty fish in our weekly diet as opposed to omega-3 fatty acids supplements (fish oil supplements).

Another relevant study worth considering:
Last year, a large meta-analysis and systematic review in JAMA found no cardiovascular benefits with fish oil supplements.

Joel T. Nowak, M.A., M.S.W.