Breast Cancer Risk Lowered Through Consumption of Oily Fish: A Study

Fatty acids found in fish may reduce a person's chance of developing breast cancer later in life, a new study found.

Published by BMJ.com, researchers found that each 0.1 gram-per-day or 0.1 percent-per-day increment of intake of n-3 polyunsaturated fatty acid (n-3 PUFA) derived from fish was associated with a five percent reduction in breast cancer risk.

To achieve this risk reduction, however, intake of oily fish such as salmon, tuna or sardines has to fall between one to two portions per week, the scientists found.

The group of researchers, based in China, set out to investigate the association between fish and n-3 PUFA intake and the risk of breast cancer due to the fact that, while n-3 PUFAs are believed to be the most promising types of fat in reducing cancer risk, results from human studies are inconsistent.

To come to their conclusions, the team reviewed and analyzed the results of 26 studies from the United States, Europe and Asian involving more than 800,000 participants and more than 20,000 cases of breast cancer.

In doing so, they found that marine n-3 PUFA was associated with a 14 percent reduction of breast cancer between the highest and lowest category of marine n-3 PUFA intake.

The risk was lowest in Asian populations, probably because fish intake is much higher in Asia than in western countries, say the authors.

Based on these results, the authors concluded that the study "provides solid and robust evidence that marine n-3 PUFA are inversely associated with breast cancer."

The reason for this, according to researchers, may be due to its involvement in chemical messaging in the brain as well as helping to regulate blood vessel activity and areas of the immune system.

Going forward, the scientists argue, the protective effect of fish or individual n-3 PUFA "warrants further investigation."

Breast cancer is one of the most common cancers, with 12 percent of women living in the United States developing an invasive form of the disease over the course of her lifetime.