First, it speeds up the aging of your immune system.

Mental stress can take a serious toll on your physical health.

• All types of stress, from everyday pressures to traumatic life events, affect your well-being.
• As you age, stress may contribute to a weakened immune system and a shorter lifespan.

Everyday stress could be making you sick.

Why do some people stay healthy as they get older while others at the same age develop chronic diseases and even die relatively young? While it has something to do with individual genetic makeup, researchers at the University of Southern California say it may also have a lot to do with individual stress levels.

The researchers looked at a national sample of more than 5,700 community-dwelling American adults over 50, with a median age of 68 years. Through self-reporting of socioeconomic status and lifestyle factors by participants, they assessed five stressors commonly believed to affect health. These include chronic stress, stressful life events, everyday discrimination, lifetime discrimination, and life trauma.

Stress changes your immune system by increasing inflammation and decreasing the system’s ability to respond to viruses and other invaders. All types of stress—from everyday personal and professional stress to the stress of traumatic life events—speed up the aging of your immune system, the researchers suggest. An aging immune system, in turn, increases your risk of developing cancer, heart disease, infectious diseases, organ failure, and premature death. When your immune system is weakened, vaccines are less effective, and individual organ systems in your body age more rapidly.

As it is, the immune system naturally weakens with age as disease- and infection-fighting white blood cells wear out, and fewer new cells are developed to replace them. Add to the equation a lifetime of stressful events, and you have even more rapid immune system aging.

These researchers specifically looked at the relationships between different types of stress and individual T cell counts. T cells are a type of “fighter” cell within the immune system that protects the body from disease by seeking out, recognizing, and destroying infected cells. They are found in every organ and body part. T cells also play an important protective role in immune system aging.

The researchers found that different types of stress affect the ratio of older, weakened T cells that are less active in the immune system to newly formed T cells that could help boost immunity. Higher incidence of life trauma and chronic stress were linked to lower levels of one type of newly formed T cells. Higher incidence of stressful life events, a lifetime of discrimination, and life trauma appeared related to lower levels of another type of new T cells.

Chronic stress, along with experiences of discrimination, was associated with higher levels of dying cells. Stressful life events, high lifetime discrimination, and chronic stress were linked to a higher percentage of yet another type of dying T cell.

The researchers propose that varying levels of different types of stress in individuals of the same age contribute to the aging and weakening of the immune system by either increasing the destruction of existing T cells or reducing the development of new T cells. These findings could help explain why some people develop chronic illness and die from infectious diseases as they age while others of the same age live relatively healthy and longer lives.

References

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, June 13, 2022; 119 (25) DOI: 10.1073/pnas.2202780119

Reviewed by Vanessa Lancaster