Stressed men have 'softer' babies, says study
Research finds that stress affects sperm quality and makes offspring less resilient to pressure.
A new study finds that the children of overly-stressed men may be less resilient and more prone to sensitivity to stress and even post traumatic stress disorder.
The study demonstrated how mild to moderate stress may affect the way men’s sperm develops and the resulting changes meant that these fathers passed down genetic coding for a less effective hormonal response to stress to their children.
This so-called 'blunted' hormonal response has been associated with those who develop certain neuropsychological disorders, including PTSD and autism.
Scientists have only recently been paying increasing attention to how a father's health impacts his children.
Three major hormones are released by the nervous system when the body is under stress. These are adrenaline, cortisol and norepinephrine. Collectively, these hormones send our bodies into 'fight or flight' mode, which is important to the body's ability to cope with the effects of stress.
According to the study, cortisol is the dominant steroid. The University of Pennsylvania study saw researchers simulating 'mild' stress in cells taken from mice by exposing them to corticosterone.
In males, the same tract where sperm matures also releases vesicles which contain microRNA. MicroRNA can bond with sperm itself to change its composition, and, therefore, to change the genetic information passed on to offspring.
The study revealed important mechanisms behind 'how stress is transmitted across generations,' says senior study author Dr Tracy Bale at the University of Pennsylvania.
The researchers found that even the amount of corticosteroid released by males in a state of only mild stress had an effect on that tract.
If those microRNA bonded to the father's developing sperm, he would pass along the same tendency to be overly-sensitive to stress – in the hormonal sense – to his children.
Led by doctoral candidate Jennifer Chen, the researchers also found that when live male mice were placed under stress for four weeks, the hormonal effects would be present weeks later.