The National Cancer Institute has begun a 12-year study to determine if selenium and vitamin E can help prevent prostate cancer. Prostate cancer is the most common form of cancer in U.S. men and is ranked as the No. 2 cancer killer of men, after lung cancer.
SELECT (Selenium and Vitamin E Cancer Prevention Trial) is the largest-ever cancer prevention study. It will follow 32,400 healthy men from 400 locations in the United States, Puerto Rico and Canada. A network of researchers, the Southwest Oncology Group, will coordinate the study.
In two earlier studies, the dietary supplements demonstrated the ability to reduce the risk of prostate cancer. But those trials were held to examine selenium's ability to reduce skin cancer, and beta-carotene and vitamin E's ability to reduce lung cancer. In both studies, researchers identified a reduction of prostate cancer in the studies' subjects—in the first study, by more than 60 percent, in the second, by 32 percent.
Both selenium, an essential nutrient, and vitamin E, an essential fat-soluble vitamin, are antioxidants. Antioxidants are believed to be involved in cell maintenance and repair, but there are more than 1,700 studies for these two dietary supplements listed in the National Library of Medicine. Many have varying results because of different protocols and different forms of supplementation. This study, because of its size and length, will provide proper evaluation of the benefits of selenium and vitamin E.
"From our perspective a study of this magnitude and scope—and the cancer it's looking to prevent, and the fact that the National Cancer Institute is willing to look at dietary supplements rather than pharmaceuticals—is very encouraging to see," said Todd Norton, president, Sabinsa Corp., Piscataway, N.J. "As an industry, we should be dancing on the roof. It could open the door for similar dietary supplement studies."
The study is still recruiting volunteers. "We are looking for quite a few good men to join SELECT because it is an incredibly important prostate cancer prevention study, Charles A. Coltman Jr., M.D., and chairman of SWOG, said in a press release. "Previous research with vitamin E and selenium, in studies focused on other kinds of cancer, suggested that these nutrients might prevent prostate cancer. SELECT is focused on prostate cancer, and when the study is finished, we will know for sure whether these supplements can prevent the disease."
The dietary supplements will be studied separately and together. Participants will be divided into four groups that will be given selenium and a placebo, vitamin E and a placebo, selenium and vitamin E or two placebos, repectively. The men are not expected to make any other changes to their regular diet.
The study will test a dosage of 200 micrograms of selenium and 400 milligrams of vitamin E daily. Roche Vitamins Inc., Parsipanny, N.J., is providing bulk vitamin E and vitamin E placebo; Nutricia Manufacturing USA Inc., Greenville, S.C., is encapsulating the vitamin E and vitamin E placebo; and Sabinsa Corp. is providing selenium and selenium placebo, both of which are already encapsulated, according to NCI.
To find out more about this program, go to http://cancer.gov/select.
Natural Foods Merchandiser volume XXII/number 9/p. 5