Stressed out? Your molecular clock is ticking faster
The more stress you experience, the faster your genetic material ages. What's more, the life-shortening effect of stress increases as you get older. Molecular scientists at the American National Institute of Environmental Health Sciences published their findings in Cancer Epidemiology, Biomarkers & Prevention.
The researchers studied 647 women aged between 35 and 74. They used questionnaires to determine the amount of stress the women were experiencing in their lives, and they measured the amount of adrenalin, noradrenalin and cortisol in the women's urine. These are the hormones that are released under stress. The researchers also measured the length of the telomeres in the white blood cells of the women. The longer your telomeres are, the more often your cells can still divide and the longer your life expectancy is.
The relationship between stress hormones and telomere length was not clear. At least, not if you also look at the stress that women reported to be experiencing. The figure below shows the relationship between the cortisol concentration, stress and telomere length.
Chronic stress – not the fun stress you get from working out, but the serious life stress you experience if you have to look after someone who is chronically sick – probably damages the HPA-axis and lowers the cortisol level in the long run. It was in the group of women with a high level of stress and a low concentration of cortisol that the researchers found the shortest telomeres.
The life-shortening effect of stress, however, is not as great as the effect of the passing years if you look at the figure below. High stress levels take a heavier toll on those who are no longer so young.
Stress causes molecular damage, probably as a result of increased inflammatory reactions in the body, the researchers suspect. If you're still young your body can repair the damage. If you're old that's no longer possible.
Cancer Epidemiol Biomarkers Prev. 2009 Feb;18(2):551-60.
How chronic stress shortens your life 25.06.2018
More stress, less longevity hormone 01.11.2015
Stress reduces life expectancy at molecular level 07.11.2009