Women Taking Tamoxifen May Benefit from Fish Oils

Women who have breast cancer and those who are at high risk for the disease sometimes take the anti-estrogen drug tamoxifen. Tamoxifen is a medication that binds to estrogen receptors and blocks the action of estrogen on breast cancer cells. When estrogen is blocked, the breast tumor doesn't grow as rapidly, as long as a woman has estrogen-receptor positive breast cancer - the most common kind. Now researchers have discovered that women taking tamoxifen for breast cancer may also benefit from fish oils.

Fish Oil and Tamoxifen for Breast Cancer

Fish oil supplements have become a popular among Americans, because they reduce inflammation and lower the risk of heart disease. They may also help to boost the cancer-fighting power of tamoxifen.

In the laboratory, researchers induced breast tumors in a group of rats. Some of the breast cancer induced rats ate a diet consisting of 17% fish oils, while others ate a diet rich in corn oil as a control for two months. Some of the rats also received tamoxifen.

The results? The rats that feasted on the fish oil diet and took tamoxifen had lower levels of genes that stimulate the growth and spread of breast tumors, compared to the rats on the corn oil diet. The fish oil diet also boosted the activity of immune genes that help the body fight off cancer. Surprisingly, on the downside, it also stimulated genes that increase inflammation, which could be counterproductive in the fight against cancer.

Fish Oil for Breast Cancer: Can It Prevent Breast Cancer Development?

A recent study showed that fish oil supplements reduces the risk of breast cancer in post-menopausal women by 32%. This is encouraging, but not all studies looking at fish oil for breast cancer prevention show benefits. This study involving 35,000 women was an observational study, which makes it impossible to say whether there's a true cause and effect relationship.

Taking Tamoxifen, Fish Oil and Breast Cancer: The Bottom Line?

It's too early to recommend fish oils for breast cancer prevention or treatment, but taking a fish oil supplement or eating fatty fish several times a week has other heart-healthy benefits. Not everyone should take them though, especially people who have a history of a bleeding disorder or take blood thinners.

Is fish oil good for people taking tamoxifen? It looks promising, but human studies are still needed.

References:

Eurekalert.org. "Fox Chase Researchers Find That Fish Oil Boosts Responses to Breast Cancer Drug Tamoxifen"

MSN Health. " Fish Oil Supplements Linked to Lower Risk of Breast Cancer: Study"