Children and even grandchildren of older fathers may live longer than children of younger men, according to a new study.
Scientists found that children born to fathers between the ages of late 30s to early 50s inherit longer ‘telomeres’ or tiny protective caps on the ends of chromosomes that protect against aging degeneration and disease.
Co-author Professor Christopher Kuzawa, an anthropologist at Northwestern University, said that while most telomeres shorten with time, they lengthen in sperm, maybe because of the an enzyme that extend telomere length, telomerase, is high in testes.
Just as telomere shortening has been linked to aging, past studies have found that lengthening telomeres can extend life and reverse signs of aging in laboratory mice.
Many studies have linked late fatherhood to an increased likelihood of passing on harmful mutations associated with autism, schizophrenia and other disorders. Other studies have shown that children of older men also have lower intelligence scores compared to children of younger men.
However, the new findings published today in the Proceedings of the National Academy of Sciences, show that late fatherhood isn't all risk.
Researchers measured the telomere length of DNA by using blood samples collected from 1,779 young Filipino adults and their mothers and determined the ages of the children’s fathers and grandfathers.
Study results show that a person's telomeres became longer not only with their father's age at birth, but also with their paternal grandfather's age at their father's birth, meaning that the longevity effect is amplified over the generations.
Furthermore, researchers found that each year that paternal or grandpaternal reproduction was delayed was equivalent to the yearly shortening in telomere length seen in older individuals in this population, suggesting that these intergenerational changes may be biologically important.
The findings suggest that delayed paternal reproduction can lead to cumulative, multi-generational increases in telomere length in offspring which may promote longer life.
Researchers also believe that longer telomeres may delay sexual development, and instead invest energy into the extra resources necessary to maintain healthy functioning at more advanced ages.
Lead author Dan Eisenberg, a doctoral candidate in anthropology at Northwestern University, said that late fatherhood may serve as a sigh that mortality rates are low.
"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," Eisenberg said in a statement. "In such an environment, investing more in a body capable of reaching these late ages could be an adaptive strategy from an evolutionary perspective."
"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," Kuzawa added.
Previously, researchers also found that people in the top half of the range of telomere lengths lived four to five years longer than those found in the bottom half, and people with shorter telomeres were three times more likely of dying from heart disease and were over eight times as likely to die from infection.