Prostate cancer risk unaffected by micronutrients

Although previous studies suggest that high plasma concentrations of carotenoids, retinol, or tocopherols may reduce the risk of prostate cancer, recent research from Europe showed no associations between these micronutrients and overall prostate cancer risk. However, when study subjects were stratified by disease stage, both plasma lycopene and the sum of all measured plasma carotenoids were associated with reduced risk of advanced disease only.

Results of the eight-country European Prospective Investigation into Cancer and Nutrition trial were published in the American Journal of Clinical Nutrition (2007; 86:672–81).

The study included 137,001 men who were followed for a mean of 6 years. Of these, 966 incident cases of prostate cancer were identified and matched with 1,064 healthy control subjects, and blood serum and demographic data were selected at a matched time point. The relative risk of prostate cancer was estimated by conditional logistic regression, which was adjusted for smoking status, alcohol intake, body mass index, marital status, physical activity, and education level.

Overall, none of the micronutrients examined were significantly associated with prostate cancer risk, the researchers reported. For lycopene and the sum of carotenoids, there was evidence of heterogeneity between the associations with risks of localized and advanced disease. These carotenoids were not associated with the risk of localized disease, but were inversely associated with the risk of advanced disease.

Risk of advanced disease for men in the highest fifth of plasma concentrations compared with men in the lowest fifth was 0.40 (95% CI: 0.19, 0.88) for lycopene and 0.35 (95% CI: 0.17, 0.78) for the sum of carotenoids.