Opps! Sex does decrease human male lifespan.

Animal studies have suggested that castration increases lifespan in males, and now Korean researchers have examined genealogy records and lifespan of 81 Korean eunuchs to find that their average lifespan is ~14-19 years longer than that of non-castrated men of similar class. (I doubt this finding will lead to an uptick in voluntary male castrations, the trade off of minus fifteen years for what our male sex hormones make possible doesn’t seem so bad...) The abstract:

Although many studies have shown that there are trade-offs between longevity and reproduction, whether such trade-offs exist in humans has been a matter of debate. In many species, including humans, males live shorter than females, which could be due to the action of male sex hormones. Castration, which removes the source of male sex hormones, prolongs male lifespan in many animals, but this issue has been debated in humans. To examine the effects of castration on longevity, we analyzed the lifespan of historical Korean eunuchs. Korean eunuchs preserved their lineage by adopting castrated boys. We studied the genealogy records of Korean eunuchs and determined the lifespan of 81 eunuchs. The average lifespan of eunuchs was 70.0 ± 1.76 years, which was 14.4–19.1 years longer than the lifespan of non-castrated men of similar socio-economic status. Our study supports the idea that male sex hormones decrease the lifespan of men.