Sedentary older women who don't exercise are 'biologically older' than active women, study of their chromosomes shows

Photo from Center for Advancing Health

By Melissa Patrick
Kentucky Health News

A study has found that older women who sit for more than 10 hours a day and also have low physical activity have "biologically older" cells than those who are less sedentary, suggesting the importance of exercise all through life.

And Kentucky's seniors need to get up and take notice, because they are ranked third in the nation for physical inactivity, according to America's Health Rankings.

The researchers found that older women who have less than 40 minutes of moderate-to-vigorous physical activity per day and are sedentary for more than 10 hours a day are biologically eight years older than women in the study who were more active. Future studies will examine how exercise relates to biological age in younger populations and in men, says a news release about the study.

“Our study found cells age faster with a sedentary lifestyle. Chronological age doesn’t always match biological age,” said Aladdin Shadyab of the University of California San Diego Health Sciences, lead author of the study report.

Researchers determined the biological age of the older women by measuring the tiny caps found on the ends of their DNA strands, called telomeres, which protect chromosomes from deterioration and progressively shorten with age. The sedentary women in the study had shorter telomeres.

"As a cell ages, its telomeres naturally shorten and fray, but health and lifestyle factors, such as obesity and smoking, may accelerate that process. Shortened telomeres are associated with cardiovascular disease, diabetes and major cancers," says the release.

About two out of every seven Kentucky seniors are obese, almost 28 percent, and 12.4 percent of Kentucky seniors smoke, putting the state in the top five. The national average is 8.8 percent. Kentucky also has some of the highest rates of heart disease, diabetes and cancer in the nation.

The study, published online in the American Journal of Epidemiology, included nearly 1,500 women, ages 64 to 95. It was part of the larger Women's Health Initiative, a national, longitudinal study that investigates the causes of chronic disease in older women. Data was gathered from questionnaires and a device worn for seven days that tracked their activity.

“We found that women who sat longer did not have shorter telomere length if they exercised for at least 30 minutes a day, the national recommended guideline,” Shadyab said. “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.”