Nautilus
11-29-2004, 10:37 PM
Too much stress can make you old before your time
ANGUS HOWARTH
STRESS plays a major role in the premature aging of cells, which makes them more vulnerable to disease, a group of researchers has claimed.
The group studied 58 mothers, some of whom were caring for chronically ill children and experiencing high levels of stress.
The researchers, from the University of California, found that stress appeared to have a major impact at a cellular level - dramatically affecting molecules believed to play a key role in cell ageing.
Telomeres - caps of DNA at the ends of chromosomes - protect and stabilise the chromosome ends, like the tabs on the ends of shoelaces.
Over time, the telomeres shorten and provide less protection, making cells more vulnerable to degenerative age-related diseases.
The researchers found that the telomeres in the immune-system cells of women with the highest perceived psychological stress had undergone the equivalent of about ten years’ additional ageing compared with women with the lowest perceptions of stress.
The highest stress group showed significantly decreased activity of telomerase - an enzyme that rebuilds telomeres. They also had higher oxidative stress, which causes DNA damage.
The results, reported in Proceedings of the National Academy of Sciences, were described as "striking".
A researcher, Professor Elizabeth Blackburn, said: "This is the first evidence that chronic psychological stress may damp down telomerase and have a significant impact on the length of telomeres, suggesting that stress may modulate the rate of cellular ageing."
Elissa Epel, the lead researcher, added: "Numerous studies have solidly demonstrated a link between chronic psychological stress and indices of impaired health, including cardiovascular disease and weakened immune function.
"The new findings suggest a cellular mechanism for how chronic stress may cause premature onset of disease.
"Anecdotal evidence and scientific evidence have suggested that chronic stress can take years off your life. The implications of this study are that this is true at the cellular level.
"Chronic stress appears to have the potential to shorten the life of cells, at least immune cells."
It is not yet clear how stress affects telomeres, but the researchers said they suspected stress hormones may play a part. More research is planned to see whether psychological stress has an impact on telomeres in other types of cells, such as those in the cardiovascular system.
A long-term study is also measuring the length of telomeres repeatedly in participants to see whether the rate of shortening in those with the highest stress levels is faster than in those with lower stress levels.
In a separate study, a stress expert says commuters can experience greater stress than fighter pilots going into battle or police officers facing a rioting mob.
Many workers feel extreme pressure when their journeys to work goes wrong, said psychologist Dr David Lewis, who carried out the research.
While fighter pilots or police officers feel stress, they have the advantage of being relatively in control of their situation.
Hapless commuters, on the other hand, can do nothing if their train breaks down or they get stuck in a ten-mile traffic jam on the motorway.
Dr Lewis, who has written several books on stress, said the consequence was higher levels of stress among commuters in extreme circumstances.
ANGUS HOWARTH
STRESS plays a major role in the premature aging of cells, which makes them more vulnerable to disease, a group of researchers has claimed.
The group studied 58 mothers, some of whom were caring for chronically ill children and experiencing high levels of stress.
The researchers, from the University of California, found that stress appeared to have a major impact at a cellular level - dramatically affecting molecules believed to play a key role in cell ageing.
Telomeres - caps of DNA at the ends of chromosomes - protect and stabilise the chromosome ends, like the tabs on the ends of shoelaces.
Over time, the telomeres shorten and provide less protection, making cells more vulnerable to degenerative age-related diseases.
The researchers found that the telomeres in the immune-system cells of women with the highest perceived psychological stress had undergone the equivalent of about ten years’ additional ageing compared with women with the lowest perceptions of stress.
The highest stress group showed significantly decreased activity of telomerase - an enzyme that rebuilds telomeres. They also had higher oxidative stress, which causes DNA damage.
The results, reported in Proceedings of the National Academy of Sciences, were described as "striking".
A researcher, Professor Elizabeth Blackburn, said: "This is the first evidence that chronic psychological stress may damp down telomerase and have a significant impact on the length of telomeres, suggesting that stress may modulate the rate of cellular ageing."
Elissa Epel, the lead researcher, added: "Numerous studies have solidly demonstrated a link between chronic psychological stress and indices of impaired health, including cardiovascular disease and weakened immune function.
"The new findings suggest a cellular mechanism for how chronic stress may cause premature onset of disease.
"Anecdotal evidence and scientific evidence have suggested that chronic stress can take years off your life. The implications of this study are that this is true at the cellular level.
"Chronic stress appears to have the potential to shorten the life of cells, at least immune cells."
It is not yet clear how stress affects telomeres, but the researchers said they suspected stress hormones may play a part. More research is planned to see whether psychological stress has an impact on telomeres in other types of cells, such as those in the cardiovascular system.
A long-term study is also measuring the length of telomeres repeatedly in participants to see whether the rate of shortening in those with the highest stress levels is faster than in those with lower stress levels.
In a separate study, a stress expert says commuters can experience greater stress than fighter pilots going into battle or police officers facing a rioting mob.
Many workers feel extreme pressure when their journeys to work goes wrong, said psychologist Dr David Lewis, who carried out the research.
While fighter pilots or police officers feel stress, they have the advantage of being relatively in control of their situation.
Hapless commuters, on the other hand, can do nothing if their train breaks down or they get stuck in a ten-mile traffic jam on the motorway.
Dr Lewis, who has written several books on stress, said the consequence was higher levels of stress among commuters in extreme circumstances.