It is a common belief that stress can prematurely age us, but this had not been quantifiable until relatively recently.
For a long time, the medical community understood that nuclear DNA “ages” with each cell division and various genetic markers could be used to determine the age of an organism. These include the length of the telomeres and the amount of methylation of DNA at specific points.
Methylation occurs when a methyl group is added to the DNA, often during DNA repair. Over the past couple of years, scientists have developed models called epigenetic clocks to see if they can measure biological aging by examining the amount of methylation at certain sites on the DNA.
GrimAge is one of the most successful epigenetic clocks, first detailed in 2019. It can accurately predict biological decline, for example, if an individual has specific age-related conditions.
While some studies indicate the GrimAge model can predict the impact of stress in people with mental health conditions, none had looked at whether it could predict the impact of stress on the general population.
Now a group of researchers at Yale School of Medicine, New Haven, C.T. has published details of a trial in the journal Translational Psychiatry looking at whether GrimAge could be used to measure the impact of stress on accelerated biological aging in healthy 18–50 year olds.
Lead author Dr. Zachary Harvanek, psychiatry resident at Yale Department of Psychiatry, explained their reasoning in an interview with Medical News Today:
“Epigenetic aging is one of the best markers we have for aging in relatively young, relatively healthy, people.”
“We don’t have great ways to tell biological age from chronological age in your average 30 to 40 year old. When people get older, we can see their health start to decline, and they start to have changes in terms of their mobility and ultimately, some people die earlier than others.”
Measuring impact of stress in healthy populations
Between 2008–2012, 444 individuals aged 18–50 were recruited to the study from New Haven, C.T. Participants were excluded if they had a previous history of substance abuse, head injury, or chronic medical condition. Pregnant people were excluded, and breathalyzer urine tests were taken from all participants at each appointment to check for drug taking.
Participants underwent a physical health review and a separate morning biochemical evaluation after fasting overnight. Data were collected on the individuals’ overall health, fasting glucose, insulin, and cortisol levels. Background information was also recorded on participants’ drinking and smoking habits, racial identity, relationship status, income, and education level.
A clinical interview for diagnosis of psychiatric illness as well as a cumulative stress interview and self-reported assessments were also carried out. These collected data on cumulative stress, psychological resilience, self-control, and emotional regulation.
Participants also provided a blood sample for the researchers to collect epigenetic data.
Cumulative stress accelerates aging, but resilience slows it down
Among the findings, researchers determined that increased cumulative stress was associated with accelerated aging compared to chronological aging using GrimAge, and increased biological markers such as insulin resistance.
They also found, however, that emotional regulation reduced the effect of stress on accelerated aging, and self-control was also found to moderate the relationship between stress and insulin resistance.
Certain characteristics were also found to cause greater accelerated aging. For example, identifying as Black resulted in one additional year of aging for this cohort, and being of male sex added 1.2 years.
“We think it would be good to do more of a subgroup analysis based on sex or based on race, to see whether the same findings about emotion regulation and self-control hold true in those groups as well,” Dr. Harvanek told Medical News Today.
While this paper does not indicate how to prevent the impact of stress on accelerating aging, it could point to potential targets for behavioral interventions, the authors say.
Professor Derek Griffith, professor of health systems administration and oncology at Georgetown, Washington D.C. and founder and co-director of the Racial Justice Institute, told Medical News Today these results supported previous research into the issue. He said:
“In general, the idea that self-identifying as Black or male sex is related to accelerated aging is consistent with other literature. Self-identifying as Black is a useful proxy for who is likely to experience racism or greater obstacles to health and well-being over the life course. New Haven is known to have a high rate of race-based residential segregation, which suggests that the resources around where people live that are associated with being healthy and well are likely to vary by race.”
“The ‘proof of principle’ that this article represents indeed suggests that more research is needed to better understand epigenetic aging.”
While it would be important to investigate different age groups over longer periods, Prof. Griffith also noted, “It will be important for future work to consider the built and social environmental resources and stressors that also affect emotional regulation, cumulative stress, and epigenetic aging because these factors also vary by race, sex, and gender.”