Foods rich in Omega-3 fatty acids are likely to reduce the risk of breast cancer in women who are obese and in post-menopausal phase, suggests new research.
The study revealed that increasing levels of Omega-3 in the blood were linked with reduced breast density.
However, the association was found only in women with a body mass index above 29, bordering on obesity.
These fatty acids are naturally found in fatty fish, such as tuna, seafood and some nuts and seeds.
The anti-inflammatory effects found in Omega-3s, specifically Docosahexaenoic acid (DHA) - a type of fatty acid -- are preferentially protective in obese postmenopausal women.
Further, women with a normal weight have less inflammation than heavier women, and are therefore less likely to benefit from anti-inflammatory Omega-3s.
"Omega-3 fatty acids have an anti-inflammatory effect, so that's one of the reasons why we suspected it may be particularly effective in obese women," said Andrea Manni, professor at Pennsylvania State University in US.
Obesity is a major breast cancer risk factor in postmenopausal women, and scientists believe increased inflammation is an important underlying cause in this population.
The study, detailed online in the journal Cancer Prevention Research, included 266 healthy postmenopausal women with high breast density detected by routine mammograms.
The women either received no treatment, or were given Raloxifene - an antiestrogen drug, or Lovaza -- an omega-3 drug or a combination of the two drugs.
Although Lovaza contains both the fatty acids DHA and eicosapentaenoic acid (EPA), only DHA blood levels were associated with breast density reduction, the study pointed out.
