Review: Selenium, Vitamin E, and prostate cancer
 Dr. Eric Klein (photo) from the Cleveland Clinic Lerner College of Medicine, in Ohio has published a review.
Here’s a historical perspective.
1990s
- Nutritional Prevention of Cancer study
- Reported a reduction in prostate cancer risk with selenium (selenized yeast).
- The Alpha-Tocopherol, Beta-Carotene Cancer Prevention study
- Reported lower prostate cancer risk with vitamin E ({alpha}-tocopherol).
- Chinese researchers
- Selenium + vitamin E + beta-carotene reduced overall cancer mortality.
- These finding were supported by epidemiological and lab studies.
2000s
- The Selenium and Vitamin E Cancer Prevention Trial (SELECT)
- Neither selenium nor vitamin E showed benefits on major health outcomes.
- Physicians Health II Study (PHS)
- No benefit from long-term vitamin E on cancer or cardiovascular risk.
The bottom line?
Why the discrepancy in results?
Dr. Klein discusses the potential confounding effects of dosing and diet on cancer risk. He then concludes that while SELECT and PHS were well-performed large-scale controlled studies, they didn’t validate what we believe biology indicates. It’s possible that “our model systems are imperfect measures of clinical outcomes in the real world.”
3/3/09 20:47 JR