Social stress ages the immune system early, study finds

Social stress such as discrimination and family problems, along with work and financial problems, can contribute to premature aging. immune system , according to a recent study. This is a double whammy, as the immune system already deteriorates with age.

Immune aging, a phenomenon known as immunosenescence, can lead to cancer, heart disease and other age-related health conditions, as well as reduce the effectiveness of vaccines such as Covid-19, said lead author Eric Klopack, a postdoctoral fellow at the Leonard Davis School of Gerontology at the University of Southern California, United States.

“People with higher stress scores had apparently older immune profiles, with lower percentages of recent disease fighters and higher percentages of worn-out T cells,” Klopack said.

T cells are some of the body’s most important defenders, performing several key functions. The “killer” T cells can directly eliminate virus-infected and cancerous cells and help eliminate so-called “zombie cells”, senescent cells that no longer divide but refuse to die.

Senescent cells are a problem because they release a variety of proteins that affect the tissues around them. Such cells have been shown to contribute to chronic inflammation. As more and more of them accumulate in the body, they promote aging conditions such as osteoporosis, chronic obstructive pulmonary disease (COPD) and Alzheimer’s.

In addition to finding that people who reported higher levels of stress had more zombie cells, Klopack and his team found they also had fewer “naive” T cells, which are the young cells needed to fight off new invaders.

“This paper adds to the findings that psychological stress, on the one hand, and well-being and resources, on the other, are associated with immune aging,” said clinical psychologist Suzanne Segerstrom, who was not involved in the study.

Suzanne, a professor of developmental, social, and health psychology at the University of Kentucky at Lexington, has studied the connection between self-regulation, stress, and immune function.

“In one of our most recent studies … older people with more psychological resources had ‘younger’ T cells,” Suzanne said.

bad health behaviors

O study de Klopack, published in the journal Proceedings of the National Academy of Sciences (PNAS), analyzed blood biomarkers from 5,744 adults over 50 years old collected as part of the Health and Retirement Study, a long-term national study of economic, health and health stress. , marital, and family in older Americans.

People in the study were asked about their levels of social stress, which included “stressful life events, chronic stress, everyday and lifelong discrimination,” Klopack said. His responses were then compared with the levels of T cells found in blood tests.

“This is the first time that detailed information about immune cells has been collected in a large national survey,” Klopack said. “We identified that older adults with low proportions of naive cells and high proportions of older T cells have an older immune system.”

The study found that the association between stressful life events and fewer naive T cells remained strong even after comparisons of education, smoking, drinking, weight, and race or ethnicity, Klopack said.

However, when poor diet and lack of exercise were taken into account, part of the connection between social stress levels and an aging immune system disappeared.

This finding indicates that how much our immune system ages when we’re stressed is within our control, Klopack said.

How stress affects the brain

As stress hormones spread through the body, the neural circuits in the brain change, affecting our ability to think and make decisions, experts say. Anxiety increases and mood can change. All of these neurological changes affect the body, including our autonomic, metabolic and immune systems.

“The most common stressors are those that operate chronically, often at a low level, and that cause us to behave in certain ways. For example, being “stressed out” can make us feel anxious or depressed, lose sleep at night, eat comfort foods and take in more calories than our bodies need, and smoke or drink too much alcohol,” wrote renowned neuroendocrinologist Bruce McEwen in an article. 2017 review on the impact of stress on the brain.

McEwen, who made the landmark 1968 discovery that the brain’s hippocampus can be altered by stress hormones like cortisol, passed away in 2020 after 54 years of researching neuroendocrinology at Rockefeller University in New York.

“Being ‘stressed out’ can also lead us to neglect seeing friends, or taking time off from our work, or reducing our involvement in regular physical activities, as we, for example, sit at a computer and try to get out of the burden of much that we do. do,” McEwen wrote.

What to do

There are ways to stop stress midway.

Deep breathing boosts our parasympathetic nervous system, the opposite of the “flight or fight” response. Filling your chest with air to the count of six will ensure that you are breathing deeply. Moving your body as if in slow motion is another way to trigger this calming reflex, experts say.

Stop your stressful and anxious thinking with cognitive behavioral therapy or CBT, which has been shown in randomized clinical trials to alleviate depression, anxiety, obsessive thinking, eating and sleep disorders, substance abuse, post-traumatic stress disorder and more .

This practice tends to focus more on the present than the past and is typically a short-term treatment, experts say.