But another study revealed that when men delay fatherhood, they pass their longevity genes on to their offspring. According to a report in the Proceedings of the National Academy of Sciences, as a man ages, his DNA code favors a longer life.
In the celebrity world, there are plenty of old fathers: In December, comic actor Steve Martin became a first-time father at 67 with his wife, 41-year-old Anne Stringfield, according to the New York Post. When Martin's child is 21, he will be 88.
Older dads need to worry about "not being around for the bar mitzvah, much less the wedding or be able to have a first beer – they'll be dead," said Ethan Gologor, a psychologist and professor at Medgar Evers College at the City University of New York.
Gologor agreed old dads can be better fathers.
"Like so many other things, it depends on how you do it, how you prepare the child," he said, "as long as the parents have the means and the emotional stability to be honest about it."
His father's mortality doesn't bother 26-year-old Will McClaran, who works for a marketing company in Portland, Maine. He was born when his father was in his 50s.
"My dad is a health fanatic, I think in part because of his second chance to be a dad," said McClaran. "He eats everything organic, quit smoking years ago, hardly ever drinks. This past October, he had to have open heart surgery the day after his 77th birthday."
His father is already back at work.
"He has the blood pressure of a teenager. I always tell him he's going to out-live me," said McClaran. "I don't dwell on having an older dad growing up. I had a great upbringing."
McClaran said he made out far better than the two children of his father's first marriage.
"I was spoiled in a lot of ways because he was much farther along professionally in his career, so finances were never an issue," he said. "When I had friends going to Disneyland, we were going to London or Ireland."
McClaran's father was a federal drug agent and never home for his half-sisters.
"When I was growing up, he had moved away from that life and was a college professor teaching criminal justice, so his schedule was much lighter," he said. "It was a polar opposite from my sisters' experience."