How older adults spend their sedentary time — what they do while sitting — makes a difference in their chances of developing dementia, according to research published in the journal Proceedings of the National Academy of Sciences.
It found that those whose time sitting was primarily spent watching television had a 24 percent increased risk for dementia, whereas those who spent that time on a computer had a 15 percent reduced risk for dementia. The researchers explained that TV watching is cognitively passive, meaning little thinking is required, while computer use is cognitively active, meaning it (like reading) is more intellectually stimulating.
For both groups of study participants, their odds of developing dementia linked to their sitting persisted, no matter how physically active they were at other times of the day. Previous studies have pointed to physical exercise as beneficial to reducing risk for cognitive decline and dementia.
Dementia, which is not considered a normal part of aging, is an umbrella term used to describe a set of symptoms — memory loss, confusion, problems with language and reasoning, and behavioral changes — that progress over time and affect a person’s daily life and activities. Alzheimer’s disease is the most common type of dementia. Today, about 6 million people in the United States have Alzheimer’s and related dementias — most older than 65 and more women than men — and the number is expected to increase to 14 million by 2060, according to the Centers for Disease Control and Prevention.
The new research involved 146,651 adults 60 and older who did not have dementia when the study began. After tracking for about a dozen years, 3,507 participants had been diagnosed with dementia.
As the researchers concluded, “reducing cognitively passive [sedentary behaviors] like TV watching and increasing cognitively active [ones] like computer use, by even a small amount, may have an important impact on dementia risk in individuals, regardless of their engagement in physical activity.”
This article is part of The Post’s “Big Number” series, which takes a brief look at the statistical aspect of health issues. Additional information and relevant research are available through the hyperlinks.