Castration may add years to men’s lives, new research suggests.

A paper published in the Sept. 25 issue of the journal Current Biology looked at genealogical records documenting the life spans of 81 Korean eunuchs and compared them to those males from three non-eunuch families of similar socioeconomic status. Information about the eunuchs was culled from an 1805 publication called the Yang-Se-Gye-Bo, a genealogy of 385 eunuchs who worked as guards or servants at the imperial court of the Korean Chosun dynasty (1392-1910).

The eunuchs – who either lost their testicles early in life to accidents such as dog bites or had them removed to gain entry to life at the palace — lived an average of 70 years; the ages at which they died ranged from 27 to 109. Three of them lived to 100 or beyond.

By contrast, the men with intact testicles lived an average of 50.9-55.6 years (depending on which family they were from); their ages at death ranged from 13 to 100.

The paper aims to help sort out whether male reproductive hormone activity shortens men’s lives. The authors note that human males typically live shorter lives than females and that in many animal species males who are castrated live longer than those who are not. That same effect has not been document in human males, they explain.

Castration removes the organs that produce male reproductive hormones. Male reproductive hormones may interfere with immune-system function and also increase risk of adverse cardiovascular events, the paper says. Either or both could lead to a man’s dying prematurely, the authors note.

But could those longer lives be attributable to the lifestyle of a eunuch living in the royal palace? According to the authors, no: First of all, most of the eunuchs didn’t live in the palace and spent as much time elsewhere as in that environment. Even if that weren’t the case, the authors suggest, living in the palace probably wouldn’t have conferred longevity, as records show that kings and other royal men who were there full time lived only to their mid-40s, on average.