For men, maintaining a normal and fit weight may help reduce the risk of prostate cancer.  Brenda Y. Hernandez, from University of Hawaii – Honolulu (USA), and colleagues  investigated the relationship between body mass, height, and weight and prostate cancer risk in the Multiethnic Cohort, a longitudinal study involving 83,879 men, ages 45 to 75 years. Of this group, 5,554 were diagnosed with prostate cancer during an average of 9.6 years of follow-up. The researchers found that white men who gained more than 10 pounds after age 21 were at a two-fold increased risk of being diagnosed with advanced or aggressive prostate cancer.  Among black men, the risks began increasing after a 25-pound weight gain, with the effect seen with early-stage and less-aggressive prostate tumors.  In contrast, men of Japanese descent saw their prostate cancer risk decline with weight gain. 

The team speculates that racial and ethnic differences may impact how fat distributes as we age; in turn, excess body fat may raise prostate cancer risk by altering hormone levels or adversely impacting metabolism, stating that: “Ethnic differences in risk may be explained by variation in the distribution of accumulated body fat that could differentially affect prostate carcinogenesis.”