Lifetime exposure to stressful conditions is a known risk factor for poorer health, increasing the risk for early onset of age-related disease and premature death. Models had examined the driving effects centering on the sequelae of repeated and prolonged activation of the sympathoadrenal and hypothalamic-pituitary-adrenal systems.
Age is a robust determinant of immune cell population composition, with aging the immune system has a reduction in the pool of naive B and T cells, an increased pool of terminally differentiated T cells, and increased systemic inflammation.
In a recently published study, researchers focus on evaluating if social stressors that occur during adulthood have a link with how the immune system ages. The study results appear in the journal Proceedings of the National Academy of Sciences.
Accelerated Immune Aging
For the study, the team used a national sample of older US adults. The pool was from the University of Michigan’s Health and Retirement Study. The researchers analyzed responses from 5,744 adults over the age of 50 using questionnaires designed to assess experiences with social stress, stressful life events, and chronic stress. Blood samples from the participants were analyzed using flow cytometry.
They found that exposure to social stress was associated with T cell distributions indicative of accelerated immune aging. Specifically, life trauma and chronic stress were associated with a lower percentage of CD4+ naive T cells.
They also found that chronic stress was associated with a greater percentage of terminally differentiated CD4+ T cells and a lower percentage of CD8+ naive T cells.
The researchers also found that controlling cytomegalovirus (CMV) positivity reduced the connection between stress and accelerated aging, and believe that widespread CMV vaccination could be a relatively simple and potential intervention to reduce immune aging.
They also pointed out the importance of how improving diet and exercise behaviors in older adults may help offset the immune aging associated with chronic stress.
Eric T. Klopack, Eileen M. Crimmins, Steve W. Cole, Teresa E. Seeman, Judith E. Carroll. Social stressors associated with age-related T lymphocyte percentages in older US adults: Evidence from the US Health and Retirement Study. Proceedings of the National Academy of Sciences, 2022; 119 (25) DOI: 10.1073/pnas.2202780119
University of Southern California. “Stress accelerates immune aging, study finds: Traumatic life events, discrimination prematurely weaken body’s mix of immune cells.” ScienceDaily. ScienceDaily, 13 June 2022. <www.sciencedaily.com/releases/2022/06/220613150648.htm>