February 20, 2013
(USA TODAY) -- Fortunetellers claim they can forecast the future by reading tea leaves, tarot cards or your horoscope.
Now a preliminary study suggests that our susceptibility to infections such as the common cold -- and maybe even our future health overall -- may be foretold not in the creases of our palms but in the tips of our chromosomes.
These tips, called telomeres, are special DNA sequences that act like the plastic tips on shoelaces, preventing the DNA in chromosomes from unraveling. Scientists believe telomeres get shorter each time a cell divides, until a cell can't divide any further and it dies.
Scientists are interested in learning more about telomeres in order to better understand the process of aging and why people become more susceptible to disease as they get older, says James Crowe, a professor at Vanderbilt University Medical Center in Nashville, who wasn't involved in the new study.
In the study, 152 people ages 18 to 55 were deliberately exposed to a cold virus. Researchers found that adults with shorter telomeres were more likely to catch colds.
Researchers weren't really interested in predicting which people are most susceptible to colds, says study co-author Sheldon Cohen, a professor at Pittsburgh's Carnegie Mellon University. Instead, Cohen used cold infections to gauge the strength of volunteers' immune systems.
Overall, 69% of people became infected with cold viruses, and 22% actually got sick, says the study, published Tuesday in The Journal of the American Medical Association.
Those rates differed according to the length of the telomeres in a type of white blood cell: 26% of volunteers with the shortest telomeres got sick, compared with 13% of those with the longest.
That makes Cohen wonder whether the length of the telomeres in people's white blood cells is related to their overall health and future disease risk.
Studies in older adults have found that telomere length is related to the risk of age-related ailments such as heart disease, cancer and infections, Cohen says.
Some new studies suggest telomere length doesn't change much over a 10-year period. However, there has been little research into the telomeres of young people, like those in the new study.
Cohen says his study raises the intriguing possibility that telomere length isn't just a sign of chronic disease, but a predictor of it.
Crowe says the study is "provocative because it comes out of left field." He notes that the study is preliminary and that it won't be convincing unless other scientists can replicate these results. But he says many people, including doctors, wonder "why some people get infected with colds and some don't. Two seemingly healthy people might be side by side, and one gets infected and one doesn't."
One of the most intriguing questions raised by the study, Crowe says, is what causes telomeres to shorten. Earlier studies have linked shorter telomeres to smoking, radiation and psychological stress, such as early life maltreatment and taking care of a chronically ill person.
Studies also suggest that early childhood adversity can cause telomeres to shorten more quickly than normal.
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