Study links omega-3 to cancer risk

IT’S supposed to be good for you but research on the use of omega-3 oils has found they could be more harm than good.

An increased risk of prostate cancer has been associated with high levels of heart-healthy omega-3 fatty acids in the blood. High levels of trans-fatty acids actually lowered the risk, the study also found.

The research published in the American Journal of Epidemiology examined data from a US study of 3,400 men.

Researchers from Seattle’s Fred Hutchinson Cancer Research Center looked at 3,461 participants in the prostate cancer prevention trial and found that men with the most docosahexaenoic acid — DHA — in their bloodstreams were about two-and-a-half times more likely to have an aggressive form of prostate cancer.

Similar results were found in the European Prospective Investigation into Cancer and Nutrition study, where men who had the highest omega-3 levels had the highest risk for prostate cancer.

The study also found that men with the highest level of trans-fatty acids — abundant in processed foods and associated with inflammation and heart disease — were 50% less likely to have the risk of aggressive prostate cancer.

“We were stunned to see these results, and we spent a lot of time making sure the analyses were correct,” said lead researcher Theodore M Brasky. “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.”

In many recent studies, fish oil has not lived up to its marketing claims. In 2005, a Journal of the American Medical Association report showed fish oil may increase the risk of cardiac arrhythmias in some patients.