A new study revealed that elderly people who tend to spend most of their days sitting down with low physical activities are biologically older compared to those who are less sedentary.
The study, published in the American Journal of Epidemiology, showed that elderly women who sit for more than 10 hours a day and have less than 40 minutes of moderate-to-vigorous physical activity daily have older cells than those who are more active.
"Our study found cells age faster with a sedentary lifestyle. Chronological age doesn't always match biological age," said lead author Aladdin Shadyab, of Department of Family Medicine and Public Health at UC San Diego School of Medicine, in a press release.
For the study, the researchers recruited nearly 1,500 women, ages 64 to 95, from the Women's Health Initiative (WHI). The researchers draw blood samples the participants and asked them to wear an accelerometer on their right hip for seven consecutive days. The participants also completed a questionnaire.
The researchers found that elderly women who remain seated for more than 10 hours per days and less than 40 minutes of physical activity every day have shorter telomeres. Telomeres are the tiny caps on the end of DNA strands. It protects the chromosomes from deterioration and progressively shortens with age.
However, some studies showed that health and lifestyle factors can alter the natural process of telomeres accelerating their shortening. Shortened telomeres are linked with diabetes, major cancers and cardiovascular diseases.
The current study found that elderly women who sat longer but exercised for at least 30 minutes a day did not have shorter telomere length. On the other hand, elderly women who sat for at least 10 hours a day and have less than 40 minutes of exercise have a shortening of telomere equivalent to eight years, making them biologically older than their more active counterparts.