An ongoing study to simultaneously investigate the association between the risk of prostate cancer and concentrations of alpha-tocopherol, gamma-tocopherol, and selenium hopes to play a role in prostate cancer prevention. Scientists at the Johns Hopkins School of Public Health in the US claim to be the first to investigate simultaneously the association between the risk of prostate cancer and concentrations of these micronutrients when they are supplied primarily from normal dietary intake (i.e., not from supplements). In a countywide campaign in 1989, researchers from the Johns Hopkins School of Public Health collected and froze blood samples from a total of 10,456 male residents of Washington County, Md., for future study. At the time of blood donation, participants gave information about their medical and smoking histories; all supplements and medications taken within the past 48 hours; and their height and weight, both currently and at age 21. Each participant was also asked to mail in a nail clipping from the big toe so that selenium levels could be assessed. Among the men who gave a blood sample and nail clipping in 1989, 110 went on to develop prostate cancer between January 1990 and September 1996. Each of these men with prostate cancer were matched with two controls, men who had remained cancer-free. Serum levels of alpha-tocopherol and gamma-tocopherol, as well as toenail selenium levels, were measured and compared between the two groups. The researchers then compared all three micronutrients' concentrations, both singly and in combination, with each man's risk of developing prostate cancer. Median concentrations of both alpha-tocopherol and gamma-tocopherol were lower among the men with prostate cancer than among the control subjects, but these differences were statistically significant only for gamma-tocopherol. Compared with the men with the lowest levels of gamma-tocopherol, men with the highest levels had a fivefold reduction in their risk of developing prostate cancer. Also gamma-tocopherol appeared to boost the protective effects of both alpha-tocopherol and selenium. That is, compared with individuals with low concentrations of all three micronutrients, high concentrations of selenium and alpha-tocopherol were associated with a statistically significant decreased risk of prostate cancer only when high concentrations of gamma-tocopherol were also present. The authors pointed out that since alpha-tocopherol supplementation may lower gamma-tocopherol concentrations in plasma and tissues, supplementation with combined alpha- and gamma-tocopherol may be called for in future prostate cancer prevention trials.