Telomeres are the protective caps on the end of chromosomes, they deteriorate over time, reducing the size of the protective cap. Longer telomeres are better.
Psychosocial stress and telomeres
Psychoneuroimmunology (PNI) studies the connection between psychosocial processes and the immune system. Current PNI research works on the assumption that the immune system is affected by psychosocial stress through the activation of certain immune functions in the nervous system. The connection between the immune system and stress is quite well understood because we have identified a lot of the biomarkers that are connected to stress and we understand how each of these affects the immune system.
Pro-inflammatory cytokines are elevated in people suffering from depression and these cytokines have been linked to the acceleration of disease, the survival of pathogens and the recurrence of disease. We also know that stress mediates catecholamine production and so has a large impact on the functioning of the immune system through neurotransmitters such as epinephrine, norepinephrine and dopamine. The stress response and the immune system are very tightly linked.
Every time a cell divides, telomere DNA is gradually degraded due to the fidelity limits of molecular replication. As time goes on, telomeres get shorter. When they become too short, the cell begins a DNA damage response and will either stop dividing or die.
A few specialised cells are able to fight this natural telomere attrition by activating the enzyme telomerase. This increases the length of telomeres. Telomerase is important for the preservation of telomere length, long-term immune function and healthy cell function. Telomere length is a reliable marker to measure the ageing of cells. As leukocyte telomeres get shorter, there is a greater incidence of diseases such as diabetes, cancer, dementia and cardiovascular issues.
Psychological stress and telomeres
Stress influences the length of telomeres and the production of telomerase. Shorter telomeres and decreased telomerase production are linked to psychosocial stress. Specifically, stress hormones like epinephrine and cortisol are directly linked to the shortening of telomeres and a drop in the production and activity of telomerase.
Allostatic load is the bodily erosion that results from exposure to stressors. Chronic stressors directly influence the of the hypothalamic–pituitary–adrenal axis regulation by increasing cortisol levels. This increases allostatic load and interferes with the maintenance of telomeres.
People suffering from a lack of social support or prolonged bouts of depression have shorter telomeres. There is an established link between stress, chronic pain and the length of telomeres. People who are experiencing a lot of pain coupled with a high stress life have shorter telomeres than people who are not experiencing a lot of pain and live a low stress lifestyle. The combination of pain and stress accelerates damage to the immune system and the ageing of cells.
The ultimate effect of multiple stressors on the body is the erosion of telomeres. A significant negative correlation has been found between work related exhaustion and the length of telomeres. Ongoing stress places a burden on the sympathetic nervous system and this accelerates the rate of cell ageing and increases disease risk. Environmental and individual factors such as the perception of stressors, the length of exposure to stressors, individual lifestyle choices and social support all mediate the effect of stressors on telomeres.
Increasing telomere length
Active stress management has a positive effect on the body’s ability to heal. Many studies use mindfulness-based stress reduction (MBSR) to demonstrate that mindfulness is effective stress management tool. The activity of telomerase is regulated, not just by psychological stress, but also by metabolic stress which makes MBSR a good intervention for increasing the production of telomerase.
We also have evidence that exercise is protective against chronic stress. A study found the telomeres of regular exercisers to be 15x more resistant to deterioration than those of non-exercisers. A study of women who had suffered childhood abuse found that abuse victims had shorter telomeres than women who had not experienced any childhood abuse. This difference was not present in women who exercised at least three times per week. Exercise can mitigate even the negative effects of severe stress suffered during childhood, as well as accumulated life stress that has negatively affected telomere length.
- Ahola K, Sirén I, Kivimäki M, Ripatti S, Aromaa A, et al. (2012) Work-Related Exhaustion and Telomere Length: A Population-Based Study. PLOS ONE 7(7): e40186. https://doi.org/10.1371/journal.pone.0040186
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