Q&A
Questions & Answers
Got questions you’ve been carrying
around for years? Very Interesting
answers them! Mail your questions
to [email protected]Researchers working
on the artificial womb
project monitor the
vital signs and growth
of a premature lamb
in a ‘biobag’.GETTY IMAGES X3 ILLUSTRATIONS: PETER SUCHESKIWe teamed up with the folks behind BBC World Service’s CrowdScience to answer your questions
on one topic. Listen to the podcast at veryinteresting.co.za.
Why do women live longer than men?
Marnie Chesterton is the presenter of Why Do Women Live
Longer Than Men? – an episode of CrowdScience.As women have two copies
of the X chromosome, they
are protected from some
genetic faults.A What causes the differences?
In every country in the world, women live longer than
men. In the UK, women get an extra four years on
average; in Russia it’s an extra 11 years (the highest
in the world). Some of these differences in life
expectancy are down to lifestyle factors, but there’s
something much deeper encoded in our genes.
Women have two copies of the X chromosome in every
cell, whereas men have one X and one Y chromosome.
With women, if one of the genes on the X chromosome
becomes faulty, they have a healthy ‘backup’ copy.
Men, on the other hand, have to make do with any
faulty genes on their single X chromosome, which can
put them at a greater risk of disease.A When do the differences begin?
From the moment they are a ball of cells, males are
more vulnerable than females, with male babies at a
20% greater risk of dying in the womb. But according
to ageing expert Prof David Gems at University College
London, mortality in men soars once puberty hits.
Some of this is due to men’s more risky behaviour, but
studies suggest that long-term problems are caused
by the physical changes in the body created by the
hormone testosterone. A 2012 study of records from
pre-19th Century Korea showed that eunuchs who
were castrated as boys before the testosterone
surge of puberty, lived 14 to 19 years longer than
their contemporaries.A Will men ever catch up with women?
With the life expectancy differences so tied up with hormones and genetics, it
seems unlikely that men will ever close the gap entirely. But the good news is
that not all of our ageing is predetermined. The Russian gap between the
sexes, for instance, is thought to be due to the culture of heavy drinking and
smoking. As cultures can change, it’s possible for both sexes to live healthier
lives with the genetic hand they are dealt. Meanwhile, advances in our
treatment of diseases should help us to close the gap even further.