Before you settle in to watch the new season of “The Bear” or watch Team USA go for gold at the Paris Olympics, think twice about how much time you spend on the couch watching TV. Your future self might thank you.
A new study by Harvard researchers links the popular pastime of sitting and watching TV to the likelihood of reaching old age in good health: the more time spent doing the former, the lower are the chances of reaching the second.
The problem doesn’t seem to be with the sitting position in general. After accounting for various risk factors such as diet quality and smoking history, the researchers found no relationship between time spent sitting in a chair at work and the odds of aging well. Same for sitting in a car or at home and doing something other than watching TV, like reading, eating, or paying bills.
Yet for every two additional hours spent in front of the boob tube, a person’s chances of meeting the researchers’ definition of healthy aging decreased by 12 percent, according to their study published this week in JAMA Network Open.
This does not bode well for the United States, where 62% of adults 20 to 64 year olds say they watch television at least two hours a day, just like 84% of seniors.
Learn more: Even for active people, prolonged sitting shortens life and erodes health
The findings are based on data from more than 45,000 women who took part in the Nurses Heath study. All were at least 50 years old and had no major chronic illnesses in 1992, when they answered a multitude of questions about their health and what they did all day.
For example, nurses were asked how much time they spent standing or walking at work or at home. They were asked about different types of exercise, including jogging, swimming, tennis and yoga. They were asked if they mowed their own lawn.
And they were asked how many hours they spent doing all kinds of sitting.
You might not be surprised to learn that the most popular type of sitting is watching TV. More than half of women – 53% – reported watching between six and 20 hours of television per week. (The median for this group was about 15.4 hours per week.) Another 15 percent of women said they watched between 21 and 40 hours of TV each week, and 2 percent watched even more.
The nurses were followed for 20 years or until they died, whichever came first. At the end of the study period, 41% of them were still free of 11 major health problems, including cancer, diabetes, heart failure, chronic obstructive pulmonary disease and multiple sclerosis. Additionally, 44% of nurses were in good mental health, 52% had no memory problems, and 16% had no physical disabilities.
Only 8.6% of women met these four criteria, which was necessary for healthy aging.
Overall, women who watched more TV tended to be older, were more likely to smoke or drink, consumed more calories, and had a higher body mass index than women who watched less TV. The most devoted viewers were also more likely to have high blood pressure and high cholesterol.
Learn more: Get up at least once every 30 minutes. Failing to do so could shorten your life, study finds
Once researchers took these and other differences into account, they found that women who spent an hour or less each week sitting in front of the television were the most likely to age healthily. Compared to them, women who watched television for two to five hours per week were 9% less likely to be in good health; those who watched six to 20 hours per week were 19% less likely; those who watched 21 to 40 hours per week were 40% less likely; and those who watched for at least 41 hours per week were 45% less likely.
The researchers also found that replacing TV time with pretty much anything else — including sleep, for women who don’t close their eyes for more than seven hours a night — would increase their chances of healthy aging. The more vigorous the new activity, the greater the impulse.
Although the actual percentage of women who have successfully aged healthily is small, the study authors estimate that 61% more women could have joined this rarefied group if they had done four things:
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Spent at least three hours a day in light physical activity at work.
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Invest at least 30 minutes per day in moderate to vigorous physical activity.
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They kept their weight within the normal range instead of being overweight or obese.
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They limited their television time to less than three hours a day.
The study did not show that too much time in front of the television prevented nurses from aging healthily, only that there was a significant inverse correlation between the two. Still, there’s good reason to suspect that their preferred sedentary behavior bears at least part of the blame.
Previous studies have linked prolonged sitting, including watching television, to various health problems, including diseases such as breast cancer, colorectal cancer, Type 2 diabetes, heart disease And early death. (This particular study found that, compared to sitting less than three hours per day, sitting at least twice as long was associated with a 17% increased risk of premature death for men and a 34% increased risk % premature death for women.)
Learn more: Too much sitting can weaken the part of your brain that is important for memory, study suggests
But researchers at Harvard’s TH Chan School of Public Health went even further, said Dr. I-Min Leeepidemiologist at Brigham & Women’s Hospital in Boston who studies how physical activity can prevent chronic disease and prolong life.
“This study expands what we know because it looked at ‘healthy aging,'” said Lee, who was not involved in the study. “‘Health’ does not just mean the absence of disease; it includes dimensions of physical and mental health, functioning and well-being. »
All study subjects were women, but the biological mechanisms likely apply to men as well, Lee said. Still, it would be good to actually test this relationship in men, as well as in people from a wider range of racial and ethnic backgrounds, she said. (The group of women in the original Nurses’ Health Study was predominantly white.)
The youngest baby boomers are now turning 60, and the proportion of the U.S. population aged 65 or older is expected to increase from about 17% today to nearly 21% in 2050, according to the U.S. Census Bureau.
“Population aging is an important public health problem,” the study authors write, and strategies to promote healthy aging “are urgently needed.”
This story was originally published in the Los Angeles Times.