Omega-3 fatty acids may increase prostate cancer risk, says study

Omega-3 fatty acids, which are found in oily fish and fish supplements, have long been touted as having protective effects against various forms of cancer, including breast cancer, as well as heart disease.

But now, a new study suggests that men with high levels of the oils in their bloods might also have a higher risk of prostate cancer.

The research, published in the Journal of the National Cancer Institute, analyzed 834 men with prostate cancers, including 156 with high-grade cancer, and compared them to 1,393 men without prostate cancer.

Also see: Fatty acid in fish linked to lower risk of breast cancer

Researchers found that men with prostate cancer were more likely to have higher levels of omega-3 fatty acids in their blood than men without prostate cancer.

"This study confirms previous reports of increased prostate cancer risk among men with high blood concentrations of long-chain [Omega-3] fatty acids," write the researchers.

Men with high levels of EPA, DPA and DHA omega-3 fatty acids were found to have a 43 per cent greater risk of prostate cancer than those with low concentrations. High levels of omega-3s equal a little more than two servings of salmon per week, reports CTV.

Also see: Can sugar help detect cancer?

The researchers acknowledge that previous research on the link between omega-3 and prostate cancer is inconclusive. They also note that the reasons why omega-3 fatty acids were linked to prostate cancer in this study are unclear. It is possible that another factor, excluding the omega-3s, caused prostate cancer in study participants.

"This is not the final word on whether omega 3 fatty acids put patients at higher risk for prostate cancer," Canadian urologist Dr. Arthur Grabowski tells CTV. He also suggests that previous studies conflict with results of this recent study.

This study follows an analysis last year of 20 fish-oil studies showing fish oil supplements offer no clear heart benefits.