One of the most important and influential studies on selenium and cancer is the NIH-funded Nutrition Prevention Cancer Trial (NPCT) published in 1996 in the Journal of the American Medical Association. The groundbreaking research sought to determine whether a nutritional supplement of selenium could decrease the incidence of cancer. The trial's stunning findings showed that daily supplementation of 200μg of selenium (from a high-selenium yeast) could reduce cancer mortality by 50 percent1 and led to additional research that substantiated the qualified health claim for selenium and cancer.
The double-blind, randomized, placebo controlled trial of 1,312 patients with an average age of 63 produced a number of intriguing findings including:
- a 63% reduction in prostate cancer
- a 58% reduction in colorectal cancer
- a 47% reduction in lung cancer
- and a 37% reduction in all cancer incidence
Given that these cancers are among the top killers, the findings have significant implications for cancer reduction and prevention. For example, based on the latest figures from the American Cancer Society, there will be an estimated 1,735,350 new cases of cancer in 2018, which is a rate of 4,754 individuals diagnosed daily.2 A 37% reduction in this would translate to more than 640,000 prevented cases of cancer each year--approximately 1,753 individuals daily. What's more, the 50 percent reduction in cancer mortality translated into more than 300,000 annual survivors or 835 individuals every day.
The prostate cancer results from the NPCT were also published in the prestigious British Journal of Urology in 1998,3 which further validated its landmark position and established the study as a benchmark for ongoing selenium research.
- Clark LC, Combs GF, Jr., Turnbull BW, et al. Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin. A randomized controlled trial. Nutritional Prevention of Cancer Study Group. JAMA. 1996;276(24):1957-1963.
- Cancer Statistics. National Cancer Institute. NIH. https://www.cancer.gov/about-cancer/understanding/statistics
- Clark LC, Dalkin B, Kronograd A, Combs Jr. GF, Turnbull BW, Slate EH, et al. Decreased incidence of prostate cancer with selenium supplementation: results of a double-blind cancer prevention trial. Br J Urol., 1998 81:730-734.