Possible risks in consuming soy foods have been heavily debated recently, especially regarding breast cancer. There is not enough evidence from human clinical trials to substantiate the claim that the isoflavones in soy contribute to breast cancer risk.
The soy and cancer study that started the controversy concerned only those with a specific type of breast cancer (estrogen receptor positive). Some early studies suggested possible increased tumor growth in rats with a high intake of soy. As more advanced research was done, scientists found that rats metabolize soy completely differently from humans, making the earlier studies invalid.
Now we know that moderate amounts of whole soy foods do not affect tumor growth or a woman’s risk of developing breast cancer. In fact, at least 10mg of soy per day can decrease breast cancer recurrence by 25 percent.
Findings from animal models have also suggested that there exists a positive correlation between tumor growth and the degree to which an isoflavone-containing product has been processed. Therefore, it is better to consume tofu and other soy foods that have undergone minimal amounts of processing, like soybeans or edamame, tofu, tempeh, and soymilk.
If anyone has concerns regarding consuming genetically modified soy or products processed with hexane gas, go organic. The USDA National Organic Standards prohibit the use of GMOs and hexane. You can also look for products with the Non-GMO Project Verified seal. Some brands with this seal include Silk, Amy’s, Back to Nature, and West Soy. For a complete list of products with the verified seal, visit nongmoproject.org.
It is the total diet or overall eating pattern that is most important in disease prevention and achieving good health. It is better to eat a diet with a variety than to concentrate on individual foods as the key to good health.