The "secret formula" for aging long and well may soon be available at your local pharmacy.
Scientists have identified a segment of human DNA that they say helps explain why some people live for almost a centuryas much as a third longer than the typical life span.
After years of studying families in which several siblings have lived to age 90 and older, the researchers pinpointed a region of chromosome 4 containing one or more genes that appears to increase an individual's chances of reaching an unusually old age.
The discovery is likely to fuel a race for the development of a pill that could extend life spans.
Until now, most researchers in the field have believed that as many as 1,000 genes influence aging in humans, much like a variety of instruments interact to play a symphony. This discovery puts much greater weight on the performance of a single section, such as the oboes or French horns.
It's also widely assumed that lifestyle habits play a significant role in longevity. Much evidence has shown that eating a balanced diet of food and abstaining from smoking and excessive consumption of alcohol, among other things, can reduce the risks of experiencing cancer, diabetes, heart disease, and strokes.
Yet the new finding suggests that extreme longevity may be linked closely with a gene or genes that give some individuals a greater resistance to diseases associated with the aging process. Most of the centenarians and near-centenarians the scientists studied were generally in good health throughout their lives regardless of their lifestyle practices.
The researchers conducted what is known as a sibling pair "linkage study." It involved 137 sets of siblings. At least one member of each set had to be 98 or older, while one or more other siblings in each set also had to be in their 90s. The researchers looked for regions of chromosomes that were identical among a large proportion of the sibling sets.
The results point to a particular region along chromosome 4 as the section of the human genome likely to contain the genetic material that predisposes certain individuals to live to an unusually old age.
"These linkage results indicate the likelihood that there exists a gene, or genes, that exerts a substantial influence on the ability to achieve exceptional old age," the scientists said in a report on their finding published in the August 28 edition of the Proceedings of the National Academy of Sciences.
The team of scientists who participated in the study are affiliated with Rutgers University, the Howard Hughes Medical Institute, Children's Hospital, Beth Israel Deaconess Medical Center, Harvard Medical School, and Whitehead Institute for Biomedical Research.
Identifying a human gene or genes that gives some people a tendency to live to extreme old age should lead to better understanding of the cellular pathways that are important to the aging process, the researchers said.
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