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Cell Biologist Finds Clues to Aging - Phychological Stress
Source: June 3, 2007, New York Times Service News by Claudia Driefus
Elizabeth H. Blackburn, a cell biologist is likely to be the next woman awarded the Nobel Prize in Medicine.
Time magazine named the biochemistry professor at the University of California, San Francisco as one of this year's ''100 Most Influential People in the World'.Winner of the 2006 Albert Lasker Award for Basic Medical Research, Dr. Blackburn studies aging and biochemical changes in cells that are related to the diseases of old age.
Question: What are telomeres and telomerase?
Answer: Telomeres are the protective caps at the ends of chromosomes in cells. Chromosomes carry the genetic information. Telomeres are buffers. They are like the tips of shoelaces. If you lose the tips, the ends start fraying.
Telomerase is an enzyme. In cells, it restores the length of the telomeres when they get worn. As the ends of the chromosomes wear down, the telomerase comes in and builds them back up.
In humans, the thing is that as we mature, our telomeres slowly wear down. So the question has always been: did that matter? Well, more and more, it seems like it matters.
Question: Is there a link between telomere length and stress?
Answer: In my lab, we're finding that psychological stress actually ages cells, which can be seen when you measure the wearing down of the tips of the chromosomes, those telomeres.
A few years ago, Dr. Elissa Epel, a psychologist who studies chronic stress, came to see me. She asked, 'Does stress have any effect on cell aging?' There's always been this observation that people under great stress appear to be care-worn. They look haggard, right?
So Elissa designed this study where we looked at two groups of mothers. One had normal, healthy children. The other group had a child with a chronic illness. Physiological and psychological measurements were done on everyone. With the stressed group, we found that the longer the mothers had been caring for their chronically ill child, the less their telomerase and the shorter their telomeres.
This was the first time you could clearly see cause and effect from a nongenetic influence. Genes play a role in telomerase levels, but this was not genes. This was something impacting the body that came from the outside and affecting its ability to repair itself. By the way, we found similar effects in women who were primary caregivers for partners with dementia.
Question: Is this scientific proof of the mind-body connection?
Answer: It's a proof. There have been others. Researchers have found that the brain definitely sends nerves directly to organs of the immune system and not just to the heart and the lower gut. In that way, too, the brain is influencing the body.
One of the things that came out of our study of these mothers is a link between low telomerase and stress-related diseases.
We looked at the measures for cardiovascular disease -- bad lipid profiles, obesity, all that stuff. The women with those had low telomerase.
We also looked at low telomeres and cancer. We wondered if a cell with worn down chromosome tips might divide in some abnormal way. Our findings have yet to be published, so I can't tell you much here, but we think we're onto something.
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