Folate has important effects on DNA and it is also inversely associated with the risk of some cancers, Dr. Victoria L. Stevens and colleagues from the American Cancer Society, Atlanta, report.
The researchers therefore examined the association between folate and prostate cancer among 65,836 men in the Cancer Prevention Study II Nutrition Cohort. A total of 5158 subjects were diagnosed with prostate cancer during nine years of follow-up.
The team estimated folate intakes from questionnaires administered when the men entered the study, between 1992 and 1993. Dietary folate levels ranged from less than 204 micrograms per day in men with the lowest levels to more than 347 mcg/day in men with the highest levels. Total folate intake ranged from less than 223 mcg/day in those with the lowest levels to more than 640 mcg/day in men with the highest levels.
No significant association was observed between dietary or total folate intake and overall prostate cancer risk. However, an association was found between higher folate levels and a decreased risk of having advanced prostate cancer, although this relationship was not statistically significant.
The findings also suggested that only a small increase in folate intake was enough to alter the risk of developing advanced prostate cancer, Stevens and colleagues note. However, the statistical power of the study was limited by the small number of cases of advanced prostate cancer. Further study is therefore needed to better understand these relationships.