Fish oil might lower breast cancer risk

Or it might not.

Women who take fish oil supplements may have a lower risk of developing breast cancer than those who don't, a study published Thursday suggests -- though whether the supplement itself bestows the benefit is not yet clear.

Then there is the dark side:

White's team also found that among a subgroup of women with a history of heart disease, fish oil use was actually related to an increased breast cancer risk versus non-use.

The finding, White said, is surprising and not readily explained. She added, though, that it was based on only a small number of women, and may represent a chance finding rather than a true effect of fish oil.

The current findings cannot hint at whether a fish-rich diet might help lower breast cancer risk. But, White and her colleagues note, two previous large studies did look at the relationship between women's reported omega-3 intake from food and their risk of breast cancer. Neither study uncovered any link.

It may pay to investigate something that might know: