People’s immune systems gradually deteriorate as they become older. Immunosenescence, or the ageing of the immune system, may have a role in age-related health issues, including cancer and cardiovascular disease, as well as older people’s less effective vaccination response. However, immune systems do not all mature at the same rate. My colleagues and I recently released a study that indicated that social Stress is linked to indicators of accelerated immune system ageing.
Researchers looked at data from the Health and Retirement Study, a large, nationally representative survey of U.S. individuals over 50, to understand better why persons of the same chronological age might have different immunological ages. life events, such as job loss; discrimination, such as being treated unjustly or denied care; substantial lifetime trauma, such as a family member’s life-threatening illness; and chronic Stress, such as financial hardship, are among the that HRS researchers question participants about.
Researchers also discovered that people who experienced more Stress had a lower proportion of “naive” T cells – fresh cells needed to take on new invaders the immune system hasn’t encountered before – by analysing data from 5,744 HRS participants who both provided blood and answered survey questions about Stress. They also contain a higher percentage of “late differentiated” T cells, which are older cells that have lost their capacity to combat intruders and instead create proteins that might worsen inflammation. A person’s immune system is more elderly if they have a low proportion of fresh T cells and a high number of older T cells.