(CBS News) Having a father and grandfather that waited until they were older before having a kid might boost the child's lifespan, a new study finds
The study looked at "telomere length" in blood samples collected from nearly 2,000 children in the Philippines and determined the ages of the children's fathers and paternal grandfathers. Telomeres are cap-like DNA structures on the tips of chromosomes that protect a person's genes from cell damage.
Scientists have linked telomeres to aging, finding shorter telomere lengths suggest a shorter lifespan. Telomere length shortens overtime in most tissues as a person's body ages - except in a man's sperm, where telomere length actually increases over time. That means the offspring of an older father will inherit longer telomeres from the outset.
When researchers looked at the children, they found offspring of older fathers - who gave birth after their late 30s - not only inherited longer telomeres, but the effect held true across multiple generations, such as child's paternal grandfather. So even if grandpa had a child at an older age, it might boost his eventual grandson's longevity.
"If our recent ancestors waited until later in adulthood before they reproduced, perhaps for cultural reasons, it would make sense for our bodies to prepare for something similar by investing the extra resources necessary to maintain healthy functioning at more advanced ages," study co-author Dr. Christopher W. Kuzawa, associate professor of anthropology at Northwestern University in Evanston, Ill., said in a news release.
The study is published in the June 11 issue of Proceedings of the National Academy of Sciences.
While shorter telomeres seem to cause ill health associated with aging, longer telomeres seem to promote a slow pace of aging that requires the body to invest more resources into repairing cells and tissues.
The researchers hope the study will shed more light on the evolution of aging.
"When we think of adaptation, we tend to think of it happening over hundreds of generations," study author Dan T.A. Eisenberg, a doctoral candidate in anthropology at Northwestern, said in the news release. "This study illustrates a means by which much more rapid adaptive genetic changes might occur over just a few generations."
That doesn't mean they recommend all men should wait until they're older to have a child.
Commenting on the study, Professor Thomas von Zglinicki, a cellular aging research at Newcastle University in the U.K., said more research is needed to back up the study's claims.
"Very few of the studies that linked telomere length to health in late life have studied the impact, if any, of paternal age," Zglinicki told BBC News. "It is still completely unclear whether telomere length at conception (or birth) or rate of telomere loss with age is more important for age-related morbidity and mortality risk in humans."