Stress May Prematurely Age Your Immune System

A gland called the thymus, which sits in front of and above the heart, serves as an incubator for T cells, but as we age, the thymus becomes fatty and doesn’t produce as many immune cells. Previous research has discovered that a healthy diet and exercise may slow down that aging shift.

What’s more, the researchers who conducted the current study found that the connection between stress and accelerated immune aging was not as strong when they controlled for factors such as poor diet and infrequent exercise.

“What this means is, people who experience more stress tend to have poorer diet and exercise habits, partly explaining why they have more accelerated immune aging,” lead study author Eric Klopack, a Ph.D. scholar in the University of Southern California’s Leonard Davis School of Gerontology, said in a statement.

The researchers also suggest getting vaccinated against cytomegalovirus (CMV). People infected with this common virus are typically asymptomatic, but studies have shown it can accelerate immune aging. The researchers discovered that the connection between stress and accelerated immune aging was not as strong when they controlled for CMV positivity.

“Widespread CMV vaccination could be a relatively simple and potentially powerful intervention that could reduce the immune aging effects of stress,” the researchers said.  

What the study did

Relying on data collected through the University of Michigan’s Health and Retirement Study, the researchers created a national sample of 5,744 adults over 50 who had answered a questionnaire designed to assess their experiences with “social stress” — including stressful life events, chronic stress, everyday discrimination and lifetime discrimination. Through blood samples taken from the participants, the researchers looked specifically at T cells (which play an important role in the body’s immune response) to see if they could find a connection between exposure to stress and a weakening immune system. The study analysis found just that — a broad range of immune-system aging among subjects of similar chronological age, with stress exposure appearing to be a factor.

Participants who experienced higher levels of lifetime discrimination and chronic stress had lower levels of naive T cells (the body’s immune sentinels) circulating in their bloodstream and higher levels of mature T cells that have spotted pathogens in the body.

“As the world’s population of older adults increases, understanding disparities in age-related health is essential. Age-related changes in the immune system play a critical role in declining health,” Klopack said. “This study helps clarify mechanisms involved in accelerated immune aging.”