Elderly women who sit for more than 10 hours a day with low physical activity have cells that are biologically older by eight years than those who are less sedentary, a new study has warned.
Researchers at University of California San Diego School of Medicine in the US found elderly women with less than 40 minutes of moderate-to-vigorous physical activity per day have shorter telomeres -- tiny caps found on the ends of DNA strands that protect chromosomes from deterioration and progressively shorten with age.
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 linked to cardiovascular disease, diabetes and major cancers.
“Our study found cells age faster with a sedentary lifestyle. Chronological age does not always match biological age,” said lead author Aladdin Shadyab from UC San Diego.
Researchers believe they are the first to objectively measure how the combination of sedentary time and exercise can impact the ageing biomarker.
Nearly 1,500 women, aged 64-95, participated in the study.
The participants completed questionnaires and wore an accelerometer on their right hip for seven consecutive days during waking and sleeping hours to track their movements.
“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,” said Shadyab.
“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,” he said.
The study was publishing in the American Journal of Epidemiology.
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