The effect of stress on telomere length has been questioned
Does stress shorten DNA or not?
Margarita Paimakova, Vesti
Telomeres are the end sections of chromosomes that look like caps that protect DNA from damage. As the body ages, telomeres gradually shorten, losing their protective function.
Different people have different telomere lengths, so telomeres can be considered an indicator of a person's biological age (as opposed to passport age). Short telomeres are associated with heart disease, metabolic syndrome, neurodegenerative and other chronic diseases.
It is well known that the length of telomeres is associated with diseases, but scientists have long wondered whether it could depend on what is happening in a person's mind. In the course of laboratory studies using experiments on mice, it was found that the stress hormone catecholamine damages chromosomes. Other studies have confirmed that stress can shorten telomeres in humans as well.
Scientists from Stanford University, led by Maya B. Mathur, conducted the largest meta-analysis to date, systematizing data from 22 previous studies to understand the impact of stress on DNA. Scientists have found a surprisingly small and at the same time negative correlation between stress and telomere length (r = -0.06). The effect was similar for both men and women.
During the study, the subjects' stress was usually measured by questions about how they felt during the last month (for example: "How often in the last month did you feel that you were unable to control important things in your life?"). It is possible that stress may have more significant consequences in the long run. So far, very few studies have been conducted that are able to measure stress multiple times over several years or even decades, rather than months.
Since in the course of the new study, scientists used data from previous studies, they could draw conclusions about different demographic groups. Some researchers mainly worked with the high–income white population, others specifically recruited respondents who faced serious problems in life (for example, domestic violence or the need to constantly care for a sick relative), and others interviewed people with certain physical defects.
It is quite possible that stress can have a special effect on people who are constantly faced with adversity. However, their correlation was even slightly less (r = -0.10), and the difference was not statistically significant.
The authors of the new study believe that the popular hypothesis that stress damages telomeres may be questioned. Although the final conclusions are still far away, as the study raises many new questions.
Article by Mathur et al. Perceived stress and telomere length: A systematic review, meta-analysis, and methodological considerations for advancing the field is published in the journal Brain, Behavior, and Immunity.
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