Study: Diets rich in fish oil could slow spread of breast cancer

A new study in the journal Clinical & Experimental Metatasis says omega-3 fatty acids, like those typically contained in fish oil, may suppress the growth and spread of breast cancer cells in mice.

Saraswotl Khadge of the University of Nebraska Medical Centre observed that those fatty acids stopped further delayed tumors from forming and blocked the cancerous cells from spreading to other organs in mice.

The tests were conducted on two groups of adult female mice who were fed a liquid diet for which the calorie count and percentage of fat that each contained were the same. The difference was that one diet contained plant oils rich in omega-6 polyunsaturated fats, and the other diet contained fish oil rich in omega-3 fatty acids.

Researchers speculate that this might be because of the way in which omega-3 fatty acids support the body’s immune and anti-inflammatory systems.

Khadge and her colleagues found the chance that the breast cancer cells would take hold in the breast glands of the adult female mice was significantly lower in those on the omega-3 diet.  They observed that tumors took significantly longer to start developing in those mice, and this had an influence on their size.

Khadge said that the study “emphasizes the potential therapeutic role of dietary long-chain omega-3 fatty acids in the control of tumor growth and metastasis,” but also said that this does not mean that an omega-3 diet could summarily prevent breast cancer tumors from forming altogether.


The study was based on dietary consumption during adult life. Its findings are in line with previous studies that showed how eating fish oil-based diets during pregnancy and as a child markedly suppresses the development and spread of breast cancer.

The study results were published by EurekAlert, the online journal of the American Association for the Advancement of Science, in its Oct. 16 edition.