Hopes dashed for supplements

A new Canadian study confirms that the combination of vitamin E, selenium and soy — long touted as promising supplements to prevent prostate cancer — does not stop high-grade prostatic intraepithelial neoplasia (PIN; a possible precursor to cancer) from progressing to prostate cancer. The study, presented at the AUA Annual Meeting, confirms earlier findings from the Selenium and Vitamin E Cancer Prevention Trial (SELECT) and further examines the effect of soy on prostate cancer.

The researchers randomized 303 men to participate in two groups. The average age of the men was 62 and they all had high-grade PIN, confirmed by at least one of two biopsies in the year-and-a-half before the study selection. Men in the treatment group took the combined supplements every day for three years; treatment was stopped if a man developed invasive disease. Follow-up biopsies were done at six, 12, 24 and 36 months. The results showed that 26.4% of the men developed invasive prostate cancer, and the nutrients did not seem to minimize that risk. This supports the findings of SELECT published in January 2009 (Lippman SM et al. JAMA 2009;301[1]:39-51), which also reported that there was no benefit from taking vitamin E and selenium.