Colon cancer is the third most common form of cancer in the United States. According to a recent study researchers say estrogen may provide protection against colon cancer. In addition, soy protein may help minimize the number and size of tumors that develop.
Investigators fed five different diets to female mice and followed their progress for one year. The diets were designed to compare the effects of specific ingredients. Diet one contained milk protein, and diet two had soy protein. Both diets lacked any kind of estrogen. The other three diets contained soy protein with the addition of an estrogen component. Diet three involved soy protein and genistein, an estrogen-like compound found in soy. Diet four had Novasoy, a commercial product that contains a mixture of soy-derived compounds including genistein. Diet five contained estrone, a naturally occurring human estrogen.
To their surprise, researchers found while all the soy plus estrogen diets gave some protection, the diet containing estrone was the most effective in preventing colon cancer. The dose of estrone used was similar to the levels used in hormone replacement therapy. The mice that consumed soy protein and developed colon cancer had fewer and smaller tumors than those mice that did not have soy protein.
Specialists say there are no known harmful side effects to eating soy protein but they say that it is more beneficial to eat the food and not the supplement.