Women who maintain an active lifestyle as they get older may age more slowly than those who are more sedentary, California researchers say.
The study involved 1,500 women ages 64 to 95 and was led by Dr. Aladdin Shadyab of the University of California, San Diego, School of Medicine. Scientists found that women who spent a significant amount of time sitting and exercised for less than 40 minutes a day were biologically eight years older than their counterparts who were more inclined to fitness. Researchers recommended not sitting around for more than 10 hours a day, especially as one ages.
"Discussions about the benefits of exercise should start when we are young, and physical activity should continue to be part of our daily lives as we get older, even at 80 years old," Shadyab told BBC News Friday.
The science behind the discovery lies in our DNA. Throughout the course of our lives, our cells constantly replicate themselves. After each copy, tiny caps — called telomeres — at the end of our DNA strands shorten, exposing our chromosomes to decay. Shorter telomeres have been linked to heart disease, diabetes and cancer. The study, which appeared in the American Journal of Epidemiology, measured participating women's movements for a week through accelerometers and found that the women who exercised for at least a half-hour a day did not have shorter telomeres.
In July, a research team led by Anabelle Decottignies of the de Duve Institute at the Catholic University of Louvain in Brussels arrived at a similar conclusion. This study, which was published in the American Association for the Advancement of Science's journal, was able to identify the specific molecule, called NRF1, responsible for maintaining telomeres. Exercise, spending 45 minutes on a stationary bicycle in this case, reportedly boosted the levels of NRF1 and kept the cells "younger."
"Think about NRF1 like varnish on nails,” Decottignies told TIME Magazine. “You cannot change the nail, but you can change the varnish again and again. What you’re doing is refreshing and replacing the old section with new protective molecules at the telomeres.”