Sperm suffer damage as men age

WASHINGTON - The older men get, the more damaged their sperm are genetically, research suggests.

This could help explain recent findings that show that older men are more likely to father children with birth defects, as well as to be less fertile than younger men, the team at the University of Washington in Seattle says.

Narendra Singh and his colleagues tested 66 men aged 20 to 57 and found that the older men produced a higher percentage of sperm with highly damaged DNA.

Writing in the journal Fertility and Sterility, they said they could not tell any difference by looking at the sperm. The total number and shape of sperm were not affected by age, they said.

But DNA tests showed that older men had more sperm with highly damaged DNA than younger men.

And the older men's sperm were less likely to undergo a self-destruct mechanism called apoptosis, which is meant to get rid of damaged cells.

It may not be simply age that affects the sperm, but all the environmental damage that comes with age, the researchers said.

While men produce fresh sperm daily, the organs that are involved in its production can be affected by smoking, chemicals, sunlight and lifestyle.

"Unfortunately, we can't stop age, but men who are putting off fatherhood might want to consider their lifestyle choices to minimise their risk of infertility, or perhaps revise their timetables," says Dr Anthony Thomas, president of the Society for Male Reproduction and Urology.

"It takes healthy sperm to make a healthy baby and with more research, we can perhaps determine how to best protect sperm from DNA damage."

- REUTERS