Older dads may be bad

Men who delay fatherhood could be shortening the lives of any female offspring, researchers believe.

A study found that girls fathered by men aged 45 or older lived on average three years less than other women.

Male children, by contrast, did not suffer any loss of lifespan.

The U. S. research, which looked at lifespan and age data on 12,000 adults, added to growing evidence that women are not the only ones with a biological clock in rearing children.

Researchers believe the cause is linked to the gradual mutation of certain genes carried by the father, which are only passed on to female offspring through his X-chromosome.

These mutations may ultimately leave daughters of older fathers more vulnerable to the major diseases, they claim.

Males inherit a Y-chromosome from their father, which may explain why they do not seem to suffer the three-year reduction in lifespan.

Dr Natalia Gavrilova, of the University of Chicago's Centre on Ageing, will present her research to a conference in Sydney at the weekend.