June 17, 2009
Experts Developing New Test To Measure The Aging Process
Researchers are working on a simple blood test that will measure how fast the body's tissues are aging at a molecular level, BBC News reported.
Scientists have discovered that concentrations of a protein called p16INK4a dramatically increases as tissue ages.
At team at the University of North Carolina could potentially provide a way to assess how healthy the tissues are and how they will respond to surgery or drugs by measuring levels of the protein in test subjects.
p16INK4a is known to play a role in suppressing the development of cancer, since the protein is present in the T-cells of the immune system. T-cells play a key role in fighting disease, and repairing tissue damage.
The researchers also found a strong link between the protein and certain behaviors, such as tobacco use and physical inactivity, which are known to accelerate aging, they wrote in the journal Aging Cell.
The team noted in the report that they had overcome technical hurdles to begin perfecting a simple blood test to detect levels of the protein.
They analyzed blood samples from 170 people who filled out a questionnaire about their health and lifestyle.
"This is a major step toward a practical tool to clinically determine a person's actual molecular, as opposed to just their chronological age," said researcher Dr. Norman Sharpless.
He said they do not yet know whether the test is a good reflection of cellular age in all types of human tissues.
However, he believes it is a first step toward a better understanding of issues like the suitability of organs for transplantation, how well patients are likely to recover after surgery or the future toxicity of chemotherapy for cancer patients.
Surprisingly, levels of the protein were not linked to obesity, even though research has suggested that limiting calorie intake may help to slow down the process of aging.
This raises the possibility that a lack of exercise may have a more profound impact on molecular aging than being overweight or obese, Sharpless said.
At Kings College London, professor Tim Spector has carried out numerous studies into how aging is related to the length of strands of DNA known as telomeres, which protect our chromosomes from damage.
Spector suggests that p16INK4a clearly has potential for use as a novel marker of biological aging.
He acknowledged, however, that much more work is needed to see if it is better than the other existing marker known as telomere length.
Also, he suggested further study was needed to tell whether p16INK4a is good enough to be useful at an individual level in predicting rates of aging.
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