Soy May Reduce Risk of Colorectal Cancer

Vanderbilt University School of Medicine researchers found that women who consumed at least 10 grams of soy protein daily were one-third less likely to develop colorectal cancer in comparison to women who consumed little soy.

04/02/09 A new study published in the American Journal of Clinical Nutrition explores how soyfood consumption may lower the risk of colorectal cancer, or cancer of the colon or rectum, in postmenopausal women. According to the National Cancer Institute, an estimated 71,560 American women were diagnosed with the fourth most common cancer in 2008.

Vanderbilt University School of Medicine researchers found that women who consumed at least 10 grams of soy protein daily were one-third less likely to develop colorectal cancer in comparison to women who consumed little soy. This is the amount of soy protein available in approximately one serving of tofu (1/2 cup), roasted soy nuts (1/4 cup), edamame (1/2 cup) or soy breakfast patties (2 patties).

The study observed soy intake in 68,412 women between the ages of 40 and 70, all free of cancer and diabetes prior to the initial screening. Researchers identified 321 colorectal cancer cases after participants were monitored for an average of 6.4 years. After adjusting for confounding factors, total soyfood intake was inversely associated with colorectal cancer risk among postmenopausal women.

"Research this comprehensive demonstrates how important it is for baby boomer and older women to add soy into their daily diet," said Lisa Kelly, RD, MPH, for the United Soybean Board. "Furthermore, the study's recommended serving is a simple and affordable nutritional step towards everyday wellness."

Evidence shows soy can play an important role in a healthy diet for a variety of reasons. It is a source of high-quality protein, and contains relatively little saturated fat as well as zero grams of trans fat. Soy protein also directly lowers blood cholesterol levels. And, for postmenopausal women in particular, the largest and longest trial published to date reported that the phytoestrogens in soy reduced hot flashes by 50 percent. A range of products - from soymilk to soy burgers to soy protein bars - can help deliver soy's benefits with convenience.