Studies show that stress accelerates immune aging

A study published in the June 13 Proceedings of the National Academy of Sciences (PNAS) study explains and potentially intervenes in age-related health inequality, including the unequal sacrifice of people’s pandemics. Identify the point.

“As the world’s elderly population grows, it is essential to understand age-related health inequalities. Age-related changes in the immune system play an important role in deteriorating health,” USC said. Eric Cropack, a senior researcher who is a doctoral researcher at the University of Tokyo, said. Gerontology’s Gerontology School. “This study helps clarify the mechanisms involved in accelerating immunosenescence.”

As people grow older, the immune system naturally begins a dramatic downgrade. This is a condition called immunosenescence. With age, a person’s immune profile weakens, too many worn-out white blood cells circulate, and too few fresh “naive” white blood cells ready to accept new invaders.

Immunosenescence is associated with cardiovascular disease, increased risk of pneumonia, reduced vaccine efficacy, and organ system aging, as well as cancer.

But what explains the dramatic difference in health between adults of the same age? USC researchers have decided to see if a link between lifelong exposure to stress (known as the cause of poor health) and reduced immune system vitality can be elucidated.

They queried a vast data set from the University of Michigan’s Health and Retirement Study, a national longitudinal study of the economy, health, marriage, family status, public and private support systems of older Americans, and cross-referenced. I referred.

To calculate exposure to various forms of social stress, researchers analyzed responses from a national sample of 5,744 adults over the age of 50. Discrimination and lifelong discrimination.

Next, blood samples from participants were analyzed by flow cytometry. Flow cytometry is a lab technique that counts and classifies blood cells as they pass one by one through the narrow stream in front of the laser.

As expected, people with high stress scores have an older immune profile, a lower percentage of freshly ill fighters, and a higher percentage of white blood cell depletion. The association between stressful life events and the number of ready-to-react or naive T cells remained strong even after managing education, smoking, drinking, body mass index, race or ethnicity.

Some of the causes of stress may be out of control, but researchers say there may be workarounds.

T cells, an important component of immunity, mature in glands called the thymus, just before and above the heart. With age, the thymic tissue contracts and replaces adipose tissue, reducing the production of immune cells. Past studies have suggested that this process is accelerated by lifestyle factors such as poor diet and lack of exercise associated with social stress.

“In this study, after statistically controlling poor diet and low exercise, the relationship between stress and accelerated immunosenescence was not very strong,” said Cropack. “This means that people who experience more stress tend to have poorer diets and exercise habits, partially explaining why immunosenescence is accelerating. “

Improving diet and exercise behavior in the elderly may help offset stress-related immunosenescence.

In addition, cytomegalovirus (CMV) can be the target of intervention. CMV is an asymptomatic virus commonly found in humans and is known to have a strong effect on the promotion of immunosenescence. Like shingles and cold labialis, CMV is most often dormant, but can burn up, especially if a person is experiencing high stress.

In this study, statistical control of CMV positivity also reduced the relationship between stress and accelerated immunosenescence. Therefore, extensive CMV vaccination may be a relatively simple and potentially powerful intervention that may mitigate the effects of stress-induced immunosenescence, the researchers said.