Only your birth certificate reveals how old you are, right? Well, yes-chronologically, at least. But wouldn't it be interesting to learn your body's true age? In other words, do you at age 50 have the body of a typical 35-year-old? Or have your health habits and lifestyle aged you so that at age 50 you more closely resemble a 65-year-old physiologically? A simple blood test may soon be able to let you know how well your body is standing the test of time.

Researchers at the University of North Carolina School of Medicine recruited 170 healthy subjects for lifestyle questioning and a blood test.  The blood test measured levels of the gene p16, which is known to suppress the tumors that cause cancer. P16 levels naturally rise in everyone as they age, but people living healthful lifestyles see their p16 levels rise more slowly than others do.

"P16 senses a sick or damaged cell and stops it from dividing," explains Norman Sharpless, MD, associate professor of medicine and genetics at the University of North Carolina School of Medicine. "The cell becomes harmless." Apparently, p16 is manufactured by the body as a response to outside stresses, such as those of normal aging as well as those we impose on it in the form of poor diet, lack of exercise, and smoking. In fact, Sharpless' research found that people who exercised had lower levels of p16 than sedentary folks while smokers had noticeably higher p16 levels. Body mass index had no impact. Sharpless also cited research that found rodents who had undergone chemotherapy and radiation had higher p16 levels while those who were subjected to caloric restriction had lower levels.

The p16 blood test should be available in about a year, although it will still be limited to research use. Hopefully it will soon thereafter become a standard test for the general public. While it's clear to scientists that genetics has a big influence on how fast a body ages, there are many choices people can make to slow down that aging. "Any test that helps people make the decision to adopt a healthy lifestyle is a good thing," said Dr. Sharpless.



Source: Norman Sharpless, MD, University of North Carolina School of Medicine