More people are discovering the health benefits of fish oils, and are taking fish oil supplements to boost their levels of omega-3 fatty acids. Fish oil supplements may help to lower the risk of heart disease, reduce blood pressure, and reduce the pain and inflammation of some diseases such as arthritis due to their anti-inflammatory effects. Now, a new study finds a link between fish oil and breast cancer risk. Can taking fish oil supplements reduce the risk of breast cancer?
Fish Oil and Breast Cancer: What’s the Association?
A recent study published in the journal Cancer Epidemiology, Biomarkers, and Prevention looked at the potential benefits of fish oil supplements for preventing breast cancer. They asked over 35,000 post-menopausal women to fill out questionnaires about their use of nutritional supplements and vitamins. The women were then followed for six years to see whether or not they developed breast cancer.
What did they find? The women who took regular fish oil supplements had a thirty-two percent lower risk of breast cancer. The reduction was seen for the most common type of breast cancer in women – invasive ductal carcinoma of the breast.
Does Taking Fish Oil Supplements Prevent Breast Cancer?
The researchers were quick to point out that this study doesn’t demonstrate cause and effect – only an association between fish oil and breast cancer risk. More studies are needed to say with certainty whether taking fish oil supplements actually prevents the disease.
This isn’t the first study to show an association between fish and breast cancer. Several previous studies have found that the omega-3 fatty acids found in fish oil may reduce the risk of some types of cancer – including breast, prostate, and colon cancer. On the other hand, when the Journal of the American Medical Association conducted a review of the international studies looking at the association between fish oil and breast cancer, they found no benefits.
If there is an association between fish oil and breast cancer, no one knows the exact mechanism. It may be due to the anti-inflammatory effect that fish oil has on the body. Inflammation plays a role in the initiation and growth of many cancers – including breast cancer. Hopefully, further studies will clarify this issue.
The Bottom Line?
It’s too early to recommend taking fish oil supplements to reduce the risk of breast cancer. Randomized trials are needed for that. On the other hand, fish oils have a variety of positive health benefits. One way to get them naturally is to eat more fatty fish – but always choose fish that are known to be low in mercury and other toxins. If you’re not a fish lover, ask your doctor whether taking fish oil supplements is right for you.
JAMA 295 (4): 403′”415.