Study Allegedly Links Omega-3s to Aggressive Prostate Cancer

A Fred Hutchinson Cancer Research Center study has reportedly found that men with the highest blood percentages of the omega-3 fatty acid known as docosahexaenoic acid (DHA) “have two-and-a-half-times the risk of developing aggressive, high-grade prostate cancer compared to men with the lowest DHA levels,” according to an April 25, 2011, press release. Theodore Brasky, “Serum Phospholipid Fatty Acids and Prostate Cancer Risk: Results From the Prostate Cancer Prevention Trial,” American Journal of Epidemiology, April 2011. Based on data from 3,400 men enrolled in the Prostate Cancer Prevention Trial, the study has also claimed that, contrary to expectations, “men with the highest blood ratios of trans-fatty acids . . . had a 50 percent reduction in the risk of high-grade prostate cancer.”

The findings evidently surprised researchers, who expected that the anti-inflammatory properties of omega-3 fatty acids would reduce prostate cancer risk, while trans-fatty acids and the omega-6 fatty acids commonly found in vegetable oils would increase it. Instead, the study authors reported that not only does DHA apparently raise the risk for aggressive prostate cancer and trans fatty acids lower it, but that none of the fatty acids appeared to affect low-grade prostate cancer. They also noted that most participants with the highest DHA blood levels ate a diet high in fatty fish, as opposed to taking fish oil supplements.

“We were stunned to see these results and we spent a lot of time making sure the analyses were correct,” said the lead author. “Our findings turn what we know—or rather what we think we know—about diet, inflammation and the development of prostate cancer on its head and shine a light on the complexity of studying the association between nutrition and the risk of various chronic diseases.”