Men also hear biological clock: study

Men also hear biological clock: study
March 10, 2009 - 1:04AM
The biological clock ticks just as loudly for Australian men, new research shows.
Scientists at the University of Queensland (UQ) have found children born to older men perform poorer on intelligence tests.
Professor John McGrath analysed data from 33,000 children born and raised across the United States and the results were "startling", he says.
"It's long been known that the age of the mother is important, we've been concerned about the risk of Downs Syndrome," says Prof McGrath, from the university's Queensland Brain Institute.
"Now we need to change our position on that ... we are getting more evidence of the age of the father being just as important."
The study took in fathers aged as young as 14 and as old as 66.
Their children underwent cognitive tests at age eight months, four years and seven years, and those born to older dads generally fared worse.
Prof McGrath said it added weight to earlier studies showing children of older dads also faced a heightened risk of schizophrenia and autism.
No single age was found as a time of heightened risk for men having children, but a "general decline across the age range" was observed.
Prof McGrath thinks sperm health could explain the deterioration.
"We are concerned that older men accumulate more mutations in the developing sperm cells," he says.
"These mistakes then pile up and increase the risks of problems in the children, and it is possible that these mistakes will carry on into the next generation."
Paradoxically, when the study looked at the cognitive results of children born to older mums it produced the opposite result.
"Offspring of older women do better in similar tests, but this is usually put down to socio-economic status of women," Prof McGrath says.
The research involved a new analysis of data collected for the Collaborative Perinatal Project, one of the largest studies of children in the US, and it is published in medical journal PLoS Medicine.