Mark Haussman and a team of researchers at Bucknell University have recently discovered that high prenatal stress levels during fetal development in chickens leaves offspring at a much greater risk for having oxidative damage, hyperactive stress responses, premature aging, and shorter telomere lengths later in life.
The study, published in Proceedings of the Royal Society B last Wednesday, showed that chicken fetuses that were injected with stress hormones, glucocorticoids, were especially susceptible to overreacting to stressful situations later in life (evidenced by higher glucocorticoid levels in response to stressful stimuli) and were more prone to premature aging, reflected by accelerated telomere degradation. The chickens injected with corticoid stress hormones also took longer to return to a glucocorticoid baseline after a stressful stimulus.
Dr. Haussman (Assistant Professor Bucknell U) said that using chickens might “seem like kind of a surprising mode,” but that the results are a preliminary case strongly suggesting similar results in other species, including humans. Haussman states, “People who are chronically stressed, their cells are aging a lot more quickly than you would expect, sometimes 5 to ten years faster than you would expect. So this is real aging.”
The Bucknell University trial aimed to combine two different fields in stress biology: the science of stress hormones such as glucocorticoids, and the relationship between cellular aging and telomere length. Rsearchers at Bucknell U wanted to look at prenatal stress as a way of seeing if individuals who exhibited hyperactive responses to stress later in life might also have premature aging. Such a result would definitively show that corticoid stress hormones can actually impact cellular aging.
On the Bucknell University website, Haussan reports that when a mother experiences stress during pregnancy, “her stress hormones cross the placenta and affect the fetus, which at that time is developing its own stress regulatory system. When those offspring grow up, they have a hyperactive stress response. This means that their own stress hormones are high for longer and it is harder to turn that stress response off, which cases health risks in the long term.”
Chickens that received a stress hormone injection at the egg stage also displayed higher levels of oxidative damage and had shorter telomeres than the control group. In some instances, chickens exposed to corticoids during fetal development aged ten years faster than normal. Some birds that were 3 weeks old had cells that looked like those of a five year old, including dramatically shorter telomere lengths.