THE ESSENTIAL
- Immune aging is associated with reduced vaccine efficacy.
- Participants with social stress had lower percentages of “fresh” disease-fighting cells and higher levels of worn-out white blood cells.
For the first time, scientists from the University of California (USA) have studied the link between social stress, a known factor in poor health, and the decline in the strength of the immune system. As part of their work published in the journal Proceedings of the National Academy of Sciences (PNAS)they analyzed the responses of 5,744 people over the age of 50 to calculate exposure to various forms of social stress.
All volunteers completed a questionnaire designed to assess their experiences of social stress, including stressful life events, chronic stress, everyday discrimination, and lifetime discrimination. The researchers also analyzed the participants’ blood samples using flow cytometry, a method that counts and classifies blood cells as they pass one by one in a narrow stream.
Social stress prematurely ages the immune system
According to the authors, social stress, whether in the form of traumatic events, work strains, daily stressors or discrimination, accelerates the aging of the immune system. According to the results, people with a higher stress score were more likely to suffer from cancer, cardiovascular disease or infection.
“After statistically controlling for poor eating habits and lack of exercise, the link between stress and accelerated immune aging was not as strong. (…) This means that people who experience more stress tend to have poorer eating and exercise habits, which partly explains why they have more accelerated immune aging,” said Eric T. Klopack, author of the research, in a statement.
The scientists say this work could help explain age-related health disparities, including the uneven toll of the pandemic, and identify possible points of intervention.