Increased DHT Levels in Androgenic Alopecia Selected to Protect Men from Prostate Cancer

The document from April 1, 2014, hypothesizes that androgenic alopecia (AGA), or male pattern baldness, characterized by increased levels of dihydrotestosterone (DHT), may have been evolutionarily selected for its potential to protect against prostate cancer. It suggests that a metabolite of DHT can lead to higher levels of prostaglandin D2 (PGD₂), which may decrease prostate cancer risk and proliferation. The paper notes a consistent link between early onset frontal balding and a lower incidence of prostate cancer and proposes that baldness could signal a man's reduced risk of prostate cancer to potential mates. It critiques the vitamin D hypothesis for AGA and explores sexual selection, suggesting bald men might be perceived as more dominant and potentially live longer, providing more resources. The hypothesis is supported by the observation that anti-DHT medications are linked to an increase in high-grade prostate cancers and a genetic variant associated with low DHT levels is strongly linked to high-grade prostate cancer. The paper aims to explain the controversial literature on the relationship between AGA and prostate cancer and suggests a reason for the selection of AGA traits.