Before you get ready to binge-watch the new season of “The Bear” or watch Team USA go for gold at the Paris Olympics, think twice about the amount of time you spend on the couch in front of the TV. Your future self may thank you.
A new study by Harvard researchers links the popular pastime of sitting and watching television with the likelihood of reaching old age in good health: the more time you spend doing the former, the lower your chances of achieving the latter.
The problem doesn't seem to be with sitting in general. After controlling for a variety of risk factors, such as diet quality and smoking history, the researchers found no relationship between time spent in a chair at work and the chances of aging well. The same goes for sitting in the car or at home doing something besides watching TV, like reading, eating, or paying bills.
However, for every additional two hours spent in front of the breast tube, a person's chances of meeting the researchers' definition of healthy aging decreased by 12%, according to their study published this week in JAMA Network Open.
This does not bode well for the United States, where 62% of adults Between 20 and 64 years old say they watch television at least two hours a day, as do 84% of older people.
The findings are based on data from more than 45,000 women who participated in the Nurses' Health Study. They were all at least 50 years old and had no major chronic illnesses in 1992, when they answered a series 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 various types of exercise, such as jogging, swimming, playing tennis and doing yoga. They were asked if they mowed their own lawn.
And they were asked how many hours they spent sitting of all kinds.
A couple watches a movie on television in their Norwalk home while sharing a bowl of popcorn.
(Francine Orr / Los Angeles Times)
You may not be surprised to know that the most popular way to sit was to sit while watching television. More than half of women (53%) said they watched between six and 20 hours of television a week. (The median among this group was about 15.4 hours per week.) Another 15% of women said they watched between 21 and 40 hours of television per week, and 2% watched even more.
The nurses were tracked for 20 years or until they died, whichever came first. At the end of the study period, 41 percent of them still did not have 11 major health problems, including cancer, diabetes, heart failure, chronic obstructive pulmonary disease and multiple sclerosis. Additionally, 44% of the nurses were in good mental health, 52% had no memory problems, and 16% had no physical problems.
Only 8.6% of women met all four criteria, which was what was needed to achieve healthy aging.
In general, women who watched more television tended to be older, were more likely to be smokers or drinkers, consumed more calories, and had higher body mass index scores than women who watched less television. The most devoted television viewers were also more likely to have high blood pressure and high cholesterol.
Once the researchers accounted for these and many other differences, they found that women who spent an hour or less each week sitting in front of the TV were the most likely to achieve healthy aging. Compared to them, women who watched television between two and five hours per week were 9% less likely to be healthy older people; those who watched between six and 20 hours per week were 19% less likely; those who watched between 21 and 40 hours per week were 40% less likely; and those who watched at least 41 hours a week were 45% less likely.
The researchers also found that replacing TV time with virtually anything else, including sleep, for women who slept no more than seven hours a night, would increase their chances of healthy aging. The more vigorous the new activity, the greater the momentum.
Although the actual percentage of women who achieved healthy aging was low, the study authors estimated that another 61% of women could have joined that rarefied group if they had done four things:
- Spent at least three hours a day doing light physical activity at work.
- Invest at least 30 minutes a day in moderate to vigorous physical activity.
- They kept their weight in the normal range instead of becoming overweight or obese.
- They limited their television viewing time to less than three hours a day.
The study did not show that excessive television time caused any of the nurses to miss out on healthy aging, only that there was a significant inverse correlation between the two. Still, there is good reason to suspect that her favorite sedentary behavior was at least partly to blame.
Previous studies have linked prolonged sitting, especially while watching television, with a variety of health problems, including diseases such as breast cancer, colonectal cancer, type 2 diabetes, cardiovascular disease and early death. (That particular study found that, compared to sitting for less than three hours a day, sitting for at least twice that amount of time was associated with a 17% higher risk of premature death for men and a 34% higher risk for men. risk of premature death for women).
But researchers at the Harvard TH Chan School of Public Health have gone a step further, he said. Dr. I-Min Leeepidemiologist at Brigham & Women's Hospital in Boston who studies how physical activity can prevent chronic diseases 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' is not just the absence of disease; includes dimensions of health, function, and physical and mental well-being.”
All of the study subjects were women, but the biological mechanisms likely apply to men as well, Lee said. Still, it would be good to test this relationship in men, as well as people from a broader range of racial and ethnic backgrounds, she said. (The group of women in the original Nurses' Health Study was overwhelmingly white.)
The youngest of the Baby Boomers are turning 60, and the share of the U.S. population that is at least 65 years old is projected to rise from about 17% today to nearly 21% in 2050, according to the U.S. Census Bureau. Joined.
“Population aging is a major public health problem,” the study authors wrote, and strategies to promote healthy aging are “urgently needed.”
