The causes of stress can be very different, for example, various traumatic events, workplace tension, individual incidents in everyday life, discrimination and many others.


As a result of stress, various disorders can occur, as well as changes in the normal functions of the human body. The immune system can also be affected by stress, leading to an increased risk of various diseases - oncological, cardiovascular and infectious, such as COVID-19 .


The experts' research could help understand age-related health disparities, including the different impact on people during a pandemic.


As people age, the immune system naturally begins to decline in functionality, a condition called immunosenescence.


Over time, a person's immunity weakens, and too few newly formed "naive" white blood cells are included in his circulation to respond to emerging pathogens.


Differences in the effectiveness of the immune system in people of the same age have also been revealed. For this reason, specialists are conducting a study to determine the relationship between stress and reduced immune activity.


The researchers analyzed a large set of data that had also been used in other studies.


To determine the different forms of social stress, the researchers analyzed responses from a national sample of 5,744 adults over the age of 50.


Participants complete a questionnaire designed to assess their experiences with social stress, including stressful life events, chronic stress, the presence of discrimination in their lives, and others.


In the next stage of the study, their blood samples were analyzed by flow cytometry. This is a laboratory technique that counts and sorts blood cells as they pass one by one in a narrow stream in front of a laser.


From the results, it was found that people who have more frequent stressful situations in their lives have a reduced number of naïve T-cells, which could quickly respond to a newly emerging pathogen.


The link between stress and decreased immune activity remained the same even after excluding other factors that could affect immunity, such as smoking, alcohol, body mass index, and others.


The study was published in the journal Proceedings of the National Academy of Sciences.