Fish intake alone probably not enough to cut breast cancer risk
New research seems to heap on another reason to add servings of oily fish – salmon, tuna or sardines – to a healthy diet, finding evidence that this habit is linked to a reduced risk of breast cancer. However, although lean protein and fatty acids are wise dietary choices, experts caution that fish intake alone may not cut breast cancer risk.
The study, published online in BMJ, is a review of 21 studies examining the intake of fish and of fatty acids known as n-3 polyunsaturated fatty acids, or PUFAs. The research included more than 800,000 women in the United States, Europe and Asia, and 20,000 cases of breast cancer. These earlier studies had shown conflicting results about the protective effects of the fatty acids, inspiring the new analysis by Zhejiang University in Hangzhou, China.
The analysis found that women with a high intake of these acids had a 14 percent reduction in breast cancer risk. Specifically, every 0.1 gram consumed per day was linked to a 5 percent reduction in risk.
However, despite the study’s large sample size, the link between the consumption of fatty acids and breast cancer risk may not be cause-and-effect.
“My take on this is that it may be more than just what they eat,” said Joanne Mortimer, M.D., director of the Women’s Cancers Program at City of Hope in an interview with HealthDay. “To make an assumption that the lower risk is due entirely to diet may be a false one.”
After all, women who eat a diet high in fish and fatty acids may be eating a more healthful diet over all, or they may have a lifestyle that lowers their risk in other ways.
The conclusion: Women should not focus too much on fish for risk reduction. Further, they should take care not to eat an excess of some fish, such as swordfish, king mackerel or shark, due to potential mercury contamination.
Rather, women serious about reducing breast cancer risk should cast a broader net. Ways to reduce risk:
• Regular breast cancer screening. Women with no unusual risk factors or symptoms should follow screening guidelines. Women age 20 to 39 should conduct a monthly breast self-exam and receive a clinical breast exam every one to three years. Women age 40 and older should continue monthly self-exams, receive a yearly clinical breast exam and undergo annual mammogram screenings. Women at increased risk due to family history or other factors should consult with their doctors about earlier and more frequent screening.
• Maintain a healthy weight and exercise. Make healthy food choices – including servings of healthy fish. Stay physically active.
• Know your family history of breast cancer. If you have a mother, sister or daughter with breast cancer, ask your doctor about your risk of developing breast cancer and how you can lower it.
• Know the risks and benefits of hormone replacement therapy.
• Limit the consumptions of alcohol.