Your Body Under Stress: DNA, Cells and Aging
Stress has been linked to a host of physical and mental problems including risk factors for cardiovascular disease, poorer immune function, obesity, depression and anxiety. But why? How does stress get into our bodies and contribute to these problems?
Telomeres might be part of the answer. According to a Elissa Epal, UCSF psychologist who has studied the health impacts of stress, for decades, telomeres have a lot to do with our stress levels and with the length of our life.
Telomeres are parts of our DNA that impact how our cells reproduce. When they shorten our cells have more difficulty reproducing. Shortening occurs naturally as we age, which may account for a wide range of age-related diseases.
But these critical parts of our cells also shorten with stress, with serious health implications. People who are stressed chronically, as well as those who experience their lives as stressful have shorter telomeres.
In a 2004 study, Epal and collegues found that women who felt they had the highest levels of stress had telomeres shorter by the equivalent of at least one decade of additional aging compared to low stress women.
In essence, stress had taken the toll of a decade of living on the cells of these women.
So what can you do if you're under stress and unable to change it? Researchers are continuing to study how positive life habits can impact the length of telomeres, and, as a result, our health.
In a recent analysis of women under stress, by Elizabeth Blackburn and Epal, exercise had a positive impact on telomere length.
Women who were stressed were more likely to have short telomeres (remember shorter is related to aging), but those who were under stress, but who also exercised did not have the shortened telomeres. For those who exercised, stress was unrelated to telomere length.
Another study, led by Aoife O'Donovan, PhD and Thomas Neylan, MD, UCSF professor of psychiatry at the San Francisco VA Medical Center, examined the telomere length of people with chronic post-traumatic stress disorder. One interesting result was that exposure to childhood trauma also was associated with telomere shortening and accounted for the link between PTSD and telomeres. But this link wasn't found in people who exercised, again linking exercise to longer telomere's and, therefore, better health.
And a third study, found that individuals who maintain a physically active life-style may be protected against the effects of rumination, one of the most persistent symptoms of stress.
Are there other factors that can mediate this relationship between telomere length and stress? Quite possibly. We'll have to keep looking to the research to determine if other stress management techniques, such as mindfulness, problem solving, or relaxation have an impact at the level of our cells.