Most of us have sedentary lifestyles. We work for a fixed time — mostly seated — and get very little physical exercise. Is it harming us?
A study has found that elderly women who sit for more than 10 hours a day with low physical activity have cells that are biologically older by eight years compared to women who are less sedentary. Now, what does that mean?
It simply means that cells age faster with a sedentary lifestyle.
The study, published in American Journal of Epidemiology, found elderly women with less than 40 minutes of moderate-to-vigorous physical activity per day and who remain sedentary for more than 10 hours per day have shorter telomeres.
They are tiny caps found on the ends of DNA strands, like the plastic tips of shoelaces, that protect chromosomes from deterioration and progressively shorten with age.
“Our study found cells age faster with a sedentary lifestyle. Chronological age doesn’t always match biological age,” said Aladdin Shadyab, lead author of the study said.
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.
Nearly 1,500 women, ages 64 to 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.
Physical activity linked to slow brain ageing
A similar study, published in Neurology®, the medical journal of the American Academy of Neurology, found that exercise in older people is associated with a slower rate of decline in thinking skills that occurs with aging.
People who reported light to no exercise experienced a decline equal to 10 more years of aging as compared to people who reported moderate to intense exercise.
For the study, researchers looked at data on 876 people enrolled in the Northern Manhattan Study who were asked how long and how often they exercised during the two weeks prior to that date. An average of seven years later, each person was given tests of memory and thinking skills and a brain MRI, and five years after that they took the memory and thinking tests again.