Your article discusses the disease in Inuit men in arctic Alaska, Greenland, and Canada. Given the way temperature affects sperm production in the testicles, have the investigators considered any differences in hormone production between these men and populations in warmer climates? Not to say that diet isn’t the key factor, but the geography gave me pause.

Rich Mewes
Fort Collins, Colo.

Men in northern climates who aren’t Inuit don’t have the low rates of prostate cancer seen in the Inuits in this study. This suggests that a protective effect stems from a cultural factor .–J. Raloff