Professor Tom Kirkwood, a leading gerontologist at the University of Newcastle, believes there is now growing evidence to suggest that men are literally more disposable than women. Kirkwood had a “eureka moment” while having a bath one winter’s night in 1977, and he came up with the theory called “disposable soma”.

It has become the leading scientific explanation for why we age, why we cannot live forever — and now the reason why women live longer than men. The disposable soma theory states that, although the genes are immortal and can indeed “live forever” by being continually passed on to subsequent generations, the body or “soma” is disposable because it is designed to live only long enough to act as a vehicle for carrying genes to the next generation.

The body, just like a car, needs to be maintained continuously to keep it on the road, but as time progress, the faults and errors build up within the cells and tissues.
These faults are energetically expensive to fix and with time, they become so common that the body eventually succumbs and dies. When this occurs, depends on how much effort the body spends on fixing its mistakes.

“Could it be that women live longer because they are less disposable than men? This notion, in fact, makes excellent biological sense,” The Independent quoted Kirkwood as writing. “In humans, as in most animal species, the state of the female body is very important for the success of reproduction. The foetus needs to grow inside the mother’s womb, and the infant needs to suckle at her breast. “So if the female animal’s body is too much weakened by damage, there is a real threat to her chances of making healthy offspring.

“The man’s reproductive role, on the other hand, is less directly dependent on his continued good health,” Kirkwood stated. Females of most species tend to live longer than males, and experiments in Professor Kirkwood’s own laboratory have shown that animals that are naturally long-lived have better maintenance and repair systems than shorter-lived species.

Studies have also found that cells taken from a female body are better at repairing damage compared with cells from a male body.