Having an older father may increase lifespan

A new study published in the journal Proceedings of the National Academy of Sciences shows that fathers who wait until they are older to reproduce could be lengthening their children’s life.

The study, conducted at Northwestern University, looked at the DNA of 1,779 young adults and found that children with fathers in their late 30s to 50s at the time of conception had longer telomeres – the tips of chromosomes that determine good health and longevity.

Researchers examined telomeres in the DNA collected from both the mother’s and their children’s blood and compared children’s telomere lengths to the ages of their fathers and grandfathers when each new generation was born.

As we age our telomeres become shorter – each time a cell divides, its telomere shortens until it dies off.

Scientists have discovered that in sperm, telomeres actually lengthen with age, rather than get shorter. As men pass their DNA onto their children through sperm, these long telomeres can be inherited.

Dr. Dan Eisenberg and colleagues from the Department of Anthropology at Northwestern University found that those who had older fathers when they were born had longer telomeres than those with younger dads at birth.

Each year that a man delayed fatherhood saw an increase in telomere length equal to the length it is naturally shortened each year in middle aged adults.

This lengthening was even greater in children whose paternal grandfather was also older when he first reproduced, so the effect can be cumulative.

While on one hand delaying fatherhood can increase the risk of miscarriage, researchers believe there could be worthy long-term benefits for the child. Scientists believe inheriting long telomeres is particularly beneficial for the gut, immune system and skin.

In a news release, Eisenberg noted, “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. In such an environment, investing more in a body capable of reaching these late ages could be an adaptive strategy from an evolutionary perspective.”

Sources: Proceedings of the National Academy of Sciences, BBC, Global

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