Telomere length seems to correlate with general levels of wellbeing. This article reports on: "several studies showing that psychological stress leads to shorter telomeres - the protective caps on the ends of chromosomes that are a measure of cell age and, thus, health. The findings also suggest that exercise may prevent this damage. ... [Researchers] examined telomeres in leukocytes, or white blood cells, of the immune system, which defends the body against both infectious agents and cell damage. ... Our findings suggest that traumatic and chronic stressful life events are associated with shortening of telomeres in cells of the immune system, but that physical activity may moderate this impact ... the current research [followed] for two years 63 healthy postmenopausal women who were the primary caregivers for a family member with dementia. In an earlier analysis of 36 of these women, pessimism was associated with high levels of a pro-inflammatory protein often associated with aging and disease states, and with short telomeres. In a recent and separate analysis of the full group of women, an increase in perceived stress was related to an increase in the odds of having short telomeres only in the non-exercising women. Among those who exercised, perceived stress was unrelated to telomere length. In the current analysis of the larger group, it was revealed that an increase in perceived stress over the course of one year was associated with a decrease in telomere length during that time. ... A third study [analyzed] data from 251 healthy, non-smoking women ages 50-65 of varying activity levels. The findings showed that non-exercising women with histories of childhood abuse had shorter telomeres than those with no histories of abuse. But, in those women who exercised regularly, there was no link between childhood abuse and telomere length, after controlling for body mass index, income, education and age."