Monday, August 10, 2009

Chronic stress can take years of your life

In today’s world we are expected to be busy all the time. We are expected to work long hours and chase from one place to another. Being stressed seems to have become a lifestyle choice, in fact possibly a status symbol.


After all , those who cannot complain of high stress levels can’t possibly be successful. So to be part of the in-group better we join the I-don’t-know-how-to-relax set.


But be careful before buying into that way of life. It seems that not only actual stress but even just our perceptions of being stressed may lead to premature aging and disease.


Over the years a number of scientific studies have shown a link between chronic psychological stress and conditions such as cardiovascular disease and weakened immune function but until recently the exact mechanisms by which stress influences disease processes was unknown.

In 2004 Science Daily reported that although a study published in the November issue of Proceedings of the National Academy of Sciences, a UCSF-led team reported that psychological stress may exact its toll, at least in part, by affecting molecules believed to play a key role in cellular aging and possibly, disease development.


The team determined that chronic stress, and the perception of life stress, each had a significant impact on particular DNA-protein complexes called telomeres that promote genetic stability. Telomeres play a critical role in determining the number of times a cell divides, its health, and its life span.


Previous studies have shown that an enzyme within the cell, called telomerase, keeps immune cells young by preserving their telomere length and ability to continue dividing. Short telomeres are linked to a range of human diseases, including HIV, osteoporosis, heart disease and aging.


The UCSF study involved 58 women between the ages of 20 and 50, all of whom were biological mothers either of a chronically ill child (39 women, so-called "caregivers") or a healthy child (19 women, or "controls").


One of the most important findings of the study was that the perception of being stressed proved to have the same effects on the body as actual stress. According to Science Daily “the most striking result, (showed that) the telomeres of women with the highest perceived psychological stress - across both groups - had undergone the equivalent of approximately 10 years of additional aging, compared with the women across both groups who had the lowest perception of being stressed. The highest-stress group also had significantly decreased telomerase activity and higher oxidative stress than the lowest-stress group.”


According to co-author Elizabeth Blackburn, PhD, Morris Herzstein Professor of Biology and Physiology in the Department of Biochemistry and Biophysics at UCSF the study provided the first evidence that chronic psychological stress and the way a person perceives stress may change the rate of cellular aging.


Lead author Elissa Epel, PhD, UCSF assistant professor of psychiatry states that these findings “suggests a cellular mechanism for how chronic stress may cause premature onset of disease. … Chronic stress appears to have the potential to shorten the life of cells, at least immune cells."


But how does stress negatively influence the workings of telomerase causing people to be more susceptible to disease?


The answer came in 2008 when UCLA scientists found that the stress hormone cortisol suppresses immune cells' ability to activate their telomerase. This may explain why the cells of persons under chronic stress have shorter telomeres.


When stressed the levels of cortisol in the body rises to support a "fight or flight" response. If the hormone remains elevated in the bloodstream for long periods of time, though, it wears down the immune system.


The research was published in the May 2008 issue of the peer-reviewed journal Brain, Behavior and Immunity.


Sources:


1. UCSF-led stydy Suggests A Way Psychological Stress Gets 'Under The Skin'
2. Mechanism Behind Mind-Body Connection Discovered



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