The stresses we experience throughout our lifetime may increase our susceptibility to accelerated aging and develop age-related diseases such as cancers and physical and cognitive decline. The scientists at the Max Planck Institute of Psychiatry studied a group of African Americans and found that there may be a link between chronic exposure to highly traumatic events and accelerated epigenetic aging–that is, the participants’ predicted ages were measured to be higher than their chronological ages (the number of years a person has been alive). Scientists quantified the predicted age, also known as the biological age, by taking blood samples from participants and measuring DNA methylation levels. DNA methylation levels are measurable markers in your genes that change in response to environmental stimuli.
The researchers then asked how stress and accelerated aging correlate? When we are stressed, our bodies respond by releasing hormones like glucocorticoids. Glucocorticoids travel through our blood and bind receptors that turn genes on and off. To mimic stress, scientist gave oral dexamethasone (DEX), a type of glucocorticoid that activates glucocorticoid receptors, to the research participants. Three hours after taking DEX, participants’ blood samples were drawn, processed, and analyzed in which the DNA methylation was measured. Scientists observed that taking DEX caused changes in the research participants’ DNA methylation levels and gene activity, meaning that products made from our genetic blueprint were either increased or decreased from the normal state without DEX. Scientists noted that some of the genes affected by changes in DNA methylation were near genes involved in the epigenetic prediction of age.
This study sheds light on how psychological stresses experienced over our lifetime can cause changes in how our genes are expressed. Information in this area can help us identify risk factors and guide us towards better health management, as well as improve our understanding of how environmental factors such as stress can change our DNA.