"If your father and grandfather were able to live and reproduce at a later age, this might predict that you yourself live in an environment that is somewhat similar — an environment with less accidental deaths or in which men are only able to find a partner at later ages," said Dan T.A. Eisenberg, lead author of the study. "In such an environment, investing more in a body capable of reaching these late ages could be an adaptive strategy from an evolutionary perspective."
The study found that children with older dads inherit longer telomeres (the DNA found at the ends of chromosomes), which have been shown to promote slower aging. The connection between the father's age and telomere length is cumulative across multiple generations.
The researchers did note that their study should not be taken as a recommendation that men make a concerted effort to reproduce at later ages, as previous research has shown that older fathers are more likely to pass along harmful mutations to their offspring at the time of conception, which can lead to increased rates of miscarriage and other health issues. However, "These new findings suggest that there might also be underappreciated benefits to having an older father or grandfather," said Christopher W. Kuzawa, coauthor of the study.
The results of the study may bode well for many Hollywood dads, like Clint Eastwood, who welcomed his seventh child at the age of 63, and Michael Douglas, whose youngest was born when he was 59.