Why men don’t live longer
Q. Why do women live longer than men? A. University of Otago associate professor Christine Jasoni described this as an age-old question that had delighted women and plagued men for decades.
It’s true in other species too. Males seem to be built to live fast and die young, whereas females keep calm and carry on. As in nearly all battles of the sexes, the main players are hormones and inheritance.
It’s not surprising really: the very things that make us different in the obvious ways, also make us different in ways we don’t usually think about, like longevity. One reason women live longer is because we have estrogen. It’s responsible for all the sexy things we traditionally think of as female. But estrogen is marvellous in another way too: it delays disease, which means that women, on average, don’t start developing lifethreatening diseases until 10-20 years after men.
Indeed, men who take estrogen show delayed disease, similar to women.
It’s never really caught-on for disease prevention though, because estrogen makes men a bit more like women in other ways, too. On the flipside, males have testosterone, which makes them stronger and faster than females. But it also means their cells rev high, which gets tiring for cells after a while, so they age more rapidly. Remove testosterone and men live longer. Castrated humans, such as eunuchs, have lifespans similar to females.
It goes beyond simply hormones, however.
The final reason has to do with little structures, called mitochondria, which provide the fuel for our cells.
When mitochondria don’t work optimally, neither do our cells (a bit like poor quality feed); and this causes our bodies to age more rapidly. We inherit our mitochondria from our mothers only. Great deal for women: Through the process of evolution, mitochondria are honed to work perfectly for our needs.
Males, on the other hand, get mitochondria that are not optimised to work for them. And if testosterone is already making their cells work hard, men’s cellular engines simply burn out sooner than women’s.