|Medical Solutions for the 21st Century . . .|
|Meeting Tomorrow's Challenges Today|
E-Newsletter No. 13
It is known that alpha-tocopherol supplementation significantly reduced the risk of prostate cancer in the Alpha-Tocopherol Beta-Carotene Cancer Prevention (ATBC) Study, and that sex hormones are thought to be involved in the etiology of prostate cancer. We examined whether long-term supplementation with alpha-tocopherol modified serum hormone levels.
Men who were cancer-free, consumed 90% of the study capsules, and had both baseline and follow-up blood available were eligible for the study. One hundred men who received alpha-tocopherol were matched by age, study center, and length of time between blood draws to 100 men who received placebo. Multivariate linear regression models, which allowed for a separate intercept for each matched pair, were used to evaluate the effect of alpha-tocopherol supplementation on follow-up hormone concentrations.
Compared to men who received placebo, we found significantly lower serum androstenedione (P=0.04) and testosterone (P=0.04) concentrations among men who received alpha-tocopherol, after controlling for baseline hormone level, follow-up serum cholesterol concentration, body mass index, smoking, and fasting time. Geometric mean (95% confidence interval [CI]) androstenedione concentration among men who received alpha-tocopherol was 145ng/dl (CI 137-153ng/dl) after adjusting for covariates, compared to 158 ng/dl (CI 148-167 ng/dl) among men who received placebo. Mean testosterone concentrations for men who received alpha-tocopherol and placebo were 539 ng/dl (CI 517-562 ng/dl) and 573 ng/dl (CI 549-598 ng/dl), respectively.
These results suggest that long-term alpha-tocopherol supplementation decreases serum androgen concentrations, and could have been one of the factors contributing to the observed reduction in incidence and mortality of prostate cancer in the alpha-tocopherol treatment group of the ATBC Study.
to Newsletter Page]
[Go to Main Page]