New research provides further evidence of the long-term implications of early life psychological stress for health, after identifying a shorter life expectancy for children born between 1914-1916 whose fathers were killed or badly injured during World War I.
Lead researcher Nicolas Todd, a part of the Inserm team at the Hôpital du Kremlin-Bicêtre in France, and colleagues recently presented their results at the 55th Annual Meeting of the European Society for Paediatric Endocrinology.
Past research has indicated that the negative stresses we experience while in the womb or in early childhood - referred to as early life advertises (ELAs) - can affect our health long into adulthood.
For example, one study published in 2013 found that early life exposure to the Chinese famine of 1959-1961 increased the risk of anemia in adulthood.
However, according to Todd and colleagues, determining the effects of early life psychological stresses on health outcomes in later life has been challenging, due to lack of sufficient data on real-life historical events.
Addressing this gap in research, the Inserm team embarked on a first-of-its-kind study, taking advantage of newly accessible databases that provided information on the lifespan of more than 4,000 children born in France between 1914-1916 - during World War I (WWI).
Death of father before birth shortened lifespan by 2.2 years
The children's fathers were either severely injured or killed while fighting in WW1, meaning they met the criteria for having experienced ELAs.
For the children whose fathers were killed, the team looked at whether this tragedy occurred before their birth or after.
Each child was matched by sex, age of mother, and date and district of birth to a "control" - that is, a child whose father was not injured or killed during WWI.
Compared with the controls, the researchers found that the children who had been exposed to ELAs in early life had a shorter life expectancy; they lived an average of 1 year less.
Children whose fathers had been killed during their mother's pregnancy fared worst, the researchers found, losing an average of 2.2 years of life, compared with controls.
While the researchers were unable to identify the cause of death for those who had experienced ELAs in early life, this is something they plan to investigate in future research.
"We know that deregulation of the stress response is commonly found on animal models of ELAs, so it will be interesting to see if any evidence of this can be seen in the causes of death in the French cohort. It may give us further insight into the long-term effects of ELA," says Todd.
While further studies are clearly required, this latest research sheds some light on how stressful experiences in early life - even before birth - may have long-term implications for health.