UCLA Study Finds Fish Oil May Reduce Risk of Breast Cancer

American women who took fish oil capsules for just three months experienced changes in breast tissue that some researchers think may lower their risk of breast cancer, UCLA researchers say.

Asian women have about one-third as much breast cancer as American women. Their breasts also contain a higher amount of a fatty acid called omega-3, which is found primarily in fish. Some researchers think this increased level of omega-3 may exert a protective effect in the breasts.

In the experiment, 25 women who were in remission from breast cancer were put on a diet that included up to 4,000 milligrams daily of fish oil, soy products and lots of vegetables. Before they started, the scientists analyzed blood and breast fat specimens to determine the ratio of omega-3 to omega-6, which is found in the vegetable oils consumed by American women.

Dr. John Glaspy of UCLA’s Jonsson Comprehensive Cancer Center, who headed the study, said that in just three months on the new diet, the ratio of omega-3 in blood improved fivefold. In breast fat, the ratio improved by 40% in favor of omega-3, a change that he said was “statistically very significant.”

Glaspy cautioned that the study does not prove that a diet rich in fish oil would prevent breast cancer. A larger, longer study would be required for that, he said.

The study is to be published next week in the Journal of the National Cancer Institute.