A large study by researchers in Seattle, USA has confirmed the link between high blood concentrations of omega-3 fatty acids and an increased risk of prostate cancer.
Published in the online edition of the Journal of the National Cancer Institute, the findings indicate that high concentrations of three of the fatty acids found in fatty fish and fish-oil supplements are associated with an increased risk of prostate cancer.
This study looked at previously collected data from the SELECT investigation, a large research project that found selenium and vitamin E were not beneficial in reducing prostate cancer risk.
The latest study found that in men taking omega-3 supplementation, there was a:
- 43 percent increase in risk for all prostate cancers
- 71 percent increase in the risk of high-grade prostate cancer
- 44 percent increase risk of low-grade prostate cancer
The increase in risk for high-grade prostate cancer is important because such tumours are more likely to be fatal.
Two other studies reported similar findings, one was from the same centre in 2011 and the other from a large European study. Furthermore, an analysis of 20 studies on the effect of fish oils on cardiovascular risk, published in the Journal of the American Medical Association, found that there was no reduction in stroke or heart attack risk in patients taking fish oil supplements.
What the study doesn’t answer:
- It doesn’t explain how this effect occurs
- It doesn’t make clear what the effect of taking fish oils is in men who already have a diagnosis of prostate cancer.
The fact that these large studies have drawn similar conclusions does now mean that individuals taking these supplements should carefully consider the risks.
The reference for the study is: Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the Selenium and Vitamin E Cancer Prevention Trial. Journal of the National Cancer Institute, 2013. Published online July 11 2013