SELENIUM/GENISTEIN PREVENT COLON CANCER?
Report #7236
Newspaper reports incorrectly claim that two recent studies show that selenium and genistein prevent colon cancer.
The first study did not report that the mineral, selenium, prevents colon cancer. It showed that people with low blood levels of selenium are at high risk for colon cancer (1). Does that mean that you should take selenium pills to prevent colon cancer? No! Selenium is found mainly in the germ of whole grains which is removed along with fiber before whole grains are ground to make flour. People who eat a lot of bakery products made from white flour are therefore the ones most likely to suffer selenium and fiber deficiency. Fiber prevents colon cancer. So low blood selenium levels in colon cancer patients could be caused by not eating whole grains.
Several studies show that genistein in soybeans helps to prevent several different cancers. However, a recent study shows that genistein causes colon cancer in rats. Chemicals that prevent one type of cancer may cause others. So, these studies show that eating whole grains and soybeans may prevent colon cancer, but making flour from whole grains and taking genistein without the soybeans may cause colon cancer.
By Gabe Mirkin, M.D., for CBS Radio News
1) Russo, M.W.; Murray, S.C.; Wurzelmann, J.I.; Woosley, J.T.; Sandler, R.S. Plasma
selenium levels and the risk of colorectal adenomas. Nutrition and Cancer - an
International Journal. 1997;28(2):125-129. 2) Rao, C.V.; Wang, C.X.; Simi, B.; Lubet, R.; Kelloff, G.; Steele, V.; Reddy, B.S.
Enhancement of experimental colon cancer by genistein, Cancer Research. SEP 1, 1997;
57(17):3717-3722.
Reported 10/6/97; Checked 9/5/05