Note to Huang.
Castration of males increases life expectancy. In the past, it was assumed that for maximum effect it was necessary to remove the testicles before puberty, since exposure to male sex hormones supposedly triggers irreversible processes that accelerate aging. However, new experiments in mice showed an unexpected pattern: castration in adulthood extends life more than in youth.
The findings contradict the idea that male sex hormones consistently accelerate aging. Conversely, factors produced by the testes may be beneficial early in life but become harmful later in life. It is particularly interesting that the removal of the testicles in adulthood almost immediately eliminated the increased risk of death typical of men. This indicates that the negative effect is not so much related to irreversible damage accumulated over the years, but to the continuous action of certain biological factors.
If it is possible to determine the molecular mechanisms that turn the initially beneficial effects of male sexual factors into harmful ones, it will be possible to influence them selectively and especially at a later age.