USA - Later reproduction may extend offspring's life: study

WASHINGTON: The offspring of fathers and grandfathers who reproduced later in life could enjoy life-extending genetic benefits, including being able to father children at an older age, a new study suggests.

Researchers at Northwestern University believe the process represents an unusually rapid evolutionary adaptation in which telomeres -- DNA found at the ends of chromosomes -- lengthen, which is thought to promote healthy aging.

"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 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."

After analyzing the DNA of 1,779 young adults and their mothers in the Philippines, researchers found that children of older fathers not only inherit longer telomeres, but that the effect is cumulative across generations.

The researchers do not advise men to reproduce at later ages, as other research has shown that doing so raises the risk of passing on genetic mutations that can cause miscarriages or other health problems.

Co-author Christopher Kuzawa said more research would be necessary to see if the longer telomeres inherited from older fathers and grandfathers reduce the health problems and ailments that come with age.

"Based upon our findings, we predict that this will be the case, but this is a question to be addressed in future studies," he said.

The study appeared in the June 11-15 issue of the Proceedings of the National Academy of Sciences.

- AFP/wm