Fish Oil Doesn’t Seem to Reduce Cancer Risk

CHICAGO – Fish oil, seen as beneficial for reducing heart disease risks, probably doesn’t help prevent cancer, according to a review of studies involving more than 700,000 patients.

Researchers examined data from 38 studies that tracked patients for up to 30 years, and said most showed there is no cancer protection from omega-3 fatty acids. Although a few studies found some risk reduction for cancers of the breast, prostate and lung, those studies were relatively small and not definitive, said Dr. Catherine MacLean, the lead author and a researcher at the Rand Corp. and Greater Los Angeles Veterans Affairs Healthcare System.

“It doesn’t mean that omega-3 fatty acids don’t have other health benefits – it’s just that reducing cancer risk isn’t one of them,” Dr. MacLean said.

The review is unlikely to be the last word on the issue.

The 38 studies are too heterogeneous – involving different population groups and different levels of fish oil consumption – to provide a definitive conclusion about cancer risks, said Julie Buring, a chronic disease researcher at Harvard’s Brigham and Women’s Hospital, who was not involved in the study.

“What is supported is that right now we don’t know,” she said.