Can parents' stress impact the health of future generations?

Studies have shown that exposure to stressors accelerates the aging process. "When parents are exposed to stressors, the lifespans of their offspring and even grand offspring are often reduced. But why this happens is not well understood," said Heidinger. The researchers' paper reviews evidence that telomeres might play an important role in the process.

Telomeres are highly conserved, repetitive sections of DNA at the end of chromosomes. Together with other proteins, telomeres form protective caps at chromosome ends, which function a little bit like the plastic ends called aglets on shoelaces, to protect the laces from fraying.

During cell division and in response to stressors, telomeres get shorter while protecting the other DNA on the chromosome. Once telomeres get too short, cells stop dividing and do not function properly, which is expected to contribute to a decline in tissue function with age.

"Understanding how stress in the parental generation influences the telomere dynamics of subsequent generations will be important for predicting how early adversity impacts human health and how changing environmental conditions will influence animal populations," said Haussmann.

The review published in Biology Letters synthesizes many human and animal studies to identify current gaps in knowledge and recommend new avenues for discovery.

"There is evidence in humans, other mammals, and birds that parental stress exposure has a negative impact on the telomeres of their offspring," said Heidinger. "However, these effects can vary among developmental stages, among individuals, and among tissues within individuals and we need to know more about what causes these differences."