Children with older fathers and grandfathers have been found to be genetically programmed to live longer, a new study has revealed.
Dr Dan Eisenberg and colleagues from the Department of Anthropology at Northwestern University studied telomere inheritance in a group of young people living in the Philippines. They found that delaying fatherhood could offer several survival advantages for the offspring because the genetic make-up of sperm changes as a man ages.
This change often leads to older men developing DNA code that favours a longer life, which is a trait that is then passed to his children. The analysis was made after analysing the DNA of 1,779 young adults, and has been published in Proceedings of the National Academy of Sciences.
Previous studies have revealed that lifespan is revealed to the length of structures in telomeres that sit at the end of the chromosomes that house our genetic code, DNA. In general, a shorter telomere length means a shorter life expectancy.
Researchers have likened telomeres to the plastic tips on shoelaces, protecting chromosomal ends from damage. However, these shorten with age until the cells are no longer able to replicate.
New research from Dr Eisenberg and his team have found that in sperm, telomeres lengthen with age. This is then passed on to their children via the sperm, and can be inherited along generations. The researchers also found that telomeres, measured in blood samples, were longer in individuals whose fathers were older when they were born.
The lengthening of the telomere was increased if the child’s paternal grandfather had also been older when he became a father. Although delaying fatherhood increases the risk of miscarriage, the researchers believe there may be long-term health benefits.
Prof Thomas von Zglinicki, an expert in cellular ageing at Newcastle University, believes more research is needed. He said: “Very few of the studies that linked telomere length to health in late life have studied the impact, if any, of paternal age. 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.
“The authors did not examine health status in the first generation offspring.”