Research on 1,500 women aged 64 to 95 found those who spent many hours sitting and exercised for less than 40 minutes a day had cells that were biologically eight years older.
This research looked at telomeres - often likened to the caps at the end of shoelaces, they are made up of molecules that protect strands of chromosomes from "fraying". They protect chromosomes from deterioration and progressively shorten with age, increasing the risk of disease.
A team of researchers from the University of California recently confirmed what similar past studies found in regard to how sedentarism plays a part in one's aging process. "Chronological age doesn't always match biological age", said lead author Aladdin Shadyab. Why would they have "older" cells? Than even as we age physical activity should continue to be a significant part of our daily lives.
This new study, which was focused mainly on women, is not to be conceived as definitive proof that sedentariness causes our cells to age faster, Shadyab said.
Women who got the recommended amount of daily exercise showed no association between how much time they spent sitting and their telomere length, suggesting that physical activity might counteract the shortening that occurs with aging.
The research was supported by the National Heart, Lung, and Blood Institute, and the National Institute of Arthritis and Musculoskeletal and Skin Diseases.
For the research the team looked at almost 1,500 women ages 64 to 95 from the Women's Health Initiative (WHI), a national longitudinal study studying the chronic diseases in postmenopausal women. Cross-sectional studies can find correlations between different factors - in this case, sitting time and telomere length. Although shortened telomeres have been linked to certain diseases, everyone's telomeres shorten over time. Shadyab instead relied on more objective recordings of physical activity from accelerometers that the women wore for one week.
Saying shorter telomeres make someone "biologically older" doesn't mean much.
GETTYIt is really important for all of us to get up from our couch or office chair
Dr. Shadyab said future reviews will analyze the impacts of practice on telomeres will concentrate on men and more youthful populaces.
Doctors have tried to disentangle the effects of physical activity from the effects of being sedentary before without much success.
And the only cells studied in this research were blood cells, so we don't know whether the results would have held for brain cells, muscle cells or any other cells in the body.
Sitting down for long periods of time isn't just bad for your metabolism, it can make you age quicker too.
Shadyab and team examined the association between LTL and sedentary time using multiple linear regression models.
That suggests sedentary behavior is not the strongest factor to affect telomere length.
During the first stages of the trials, he did not necessarily see any connection between physical activity and telomere's length.