Consuming soy instead of red meat that is high in saturated fat and cholesterol may have a number of health benefits. Soy is a good source of complete protein and may help to lower your risk for high cholesterol and certain cancers, as well as reducing menopause symptoms. However, the effect of soy consumption on breast cancer risk is still not clear.
Increased Risk Theory
Soy contains substances known as phytoestrogens that can act similar to estrogen in the body. Since some breast cancers are sensitive to hormones --- estrogen increases the risk for these cancers --- there is a theory that soy may increase breast cancer risk when consumed in large amounts. However, most studies show either a decrease in breast cancer risk or no change from soy consumption.
Decreased Risk Theory
Phytoestrogens like soy have a much weaker effect on the body than estrogens, and can fill some estrogen receptors, lowering the amount of estrogen in the body --- at least in premenopausal women. This may lower the risk of breast cancer. A study presented at the American Research on Cancer meeting in 2011 found no increased risk of cancer recurrence for women who have had breast cancer.
Recommendations
Limit your soy consumption to 25 g per day, recommends Dr. Cynara Coomer, chief of Breast Surgery and director of the Comprehensive Breast Center at Staten Island University Hospital. Stick to foods that contain soy, rather than soy supplements, since foods contain other beneficial nutrients and the supplements may not have the same beneficial effects, according to the Cancer Project.
Considerations
For the most health benefits, you should consume a varied diet instead of a lot of any one food, including soy. Small amounts of soy do not pose much of a risk and can be a healthy alternative to other foods high in saturated fat. You don't have to include soy in your diet to have a healthy diet that is vegetarian or mainly vegetarian.
References
- "MSNBC"; Soy Poses No Risk to Breast Cancer Patients, Says Study; Rachael Rettner; April 2011
- "Cornell University"; Phytoestrogens and Breast Cancer; Barbour S. Warren, et al.; July 2001
- "Susan G. Komen for the Cure"; Soy; 2011
- Fox News; Soy & Breast Health; Cynara Coomer; August 2010
- The Cancer Project: Breast Cancer
