The UCSF-led team determined that chronic stress, and the perception of life stress, each had a significant impact on three biological factors - the length of telomeres, the activity of telomerase, and levels of oxidative stress - in immune system cells known as peripheral blood mononucleocytes, in healthy premenopausal women.
A greater weight of work over a much longer period of time links chronic psychological stress with poor health in general, and there is also reason to believe that shorter telomeres correlate well to poor health and greater risk of age-related disease. So does psychological stress over time cause what amounts to somewhat accelerated aging? This is plausible, but still unclear. While the research quoted above fairly clearly suggests that psychological stress leads to a less robust, more damaged immune system, with all that this implies for health and aging, the role of telomeres in the biochemical and cellular damage that accumulates with aging is not yet firmly established. They may be a root cause of age-related degeneration, or they may be a secondary marker of other processes, such as mitochondrial damage. Further, note that studies have generally looked at telomere length in only a limited population or subset of the body's different cell types.
But the data on stress and telomere length continues to arrive. At some point a firm conclusion will emerge. Here, for example, is a more recent study:
Telomere length is a measure of biological aging because telomeres shorten progressively with each cell division. Shorter telomere lengths have been linked to a variety of aging-related medical conditions including cardiovascular disease and cancer.
Stress and trauma, such as childhood abuse and neglect, are risk factors for several medical and psychiatric illnesses, and stress is known to promote cellular aging. So, Audrey Tyrka and her colleagues from Butler Hospital and Brown University examined the DNA of healthy adults who had a history of childhood maltreatment and found they had shorter telomeres than those who did not experience child maltreatment.
Dr. Tyrka explained that the findings "suggest the possibility that early developmental experiences may have profound effects on biology that can influence cellular mechanisms at a very basic level and even lead to accelerated aging."
All of which still hinges on the role of telomeres in aging, and whether telomere length in any specific cell type is a good biomarker of aging - questions that remain in need of solid answers.