March 31, 2026
Thom Carroll/for PhillyVoice
Sitting around can be bad for our health. But choosing mentally engaging hobbies like puzzles, reading and knitting rather than passively watching a screen can decrease the risk of developing dementia, a new study says.
Too much sedentary activity has been found to increase the risk of developing dementia. But a new study suggests that sitting with a pair of knitting needles, rather than just watching TV, can stave off mental decline.
Researchers examined the effects of "mentally passive" versus "mentally active" sedentary behavior on adults over a nearly 20-year period. They found that each additional hour of mentally active sedentary behavior per day was associated with a 4% lower risk of developing dementia. Swapping an hour of daily passive sedentary behavior with mentally active sedentary behavior was associated with a 7% decrease in dementia risk.
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Those who added an hour of mentally active sedentary behavior while maintaining their usual levels of mentally passive sedentary behavior and physical activity saw an 11% lower risk of developing dementia.
The "protective effect" of cognitively engaging hobbies was especially pronounced among participants ages 50-64. This finding is in line with another recent study that found "brain training" games cut the risk of developing Alzheimer's disease for older adults by 25%.
"While all sitting involves minimal energy expenditure, it may be differentiated by the level of brain activity," co-author Mats Hallgren, the principal researcher at the Karolinska Institute in Sweden, said in a news release. "How we use our brains while we are sitting appears to be a crucial determinant of future cognitive functioning and, as we have shown, may predict dementia onset."
The study was based on data from 20,811 people, ages 35 to 64, that participated in a massive health initiative by the Swedish Cancer Society, which gathered detailed lifestyle information from 43,863 people in 1997 and followed up in 2016. Participants reported how much time they typically devoted to cognitively passive activities (like listening to music and watching television) and active diversions (such as knitting, reading and puzzles) while sitting each day. The survey also captured how much daily time they spent engaging in light to vigorous physical activity.
Since the initial data was gathered in 1997, the questionnaire did not account for social media use. Hallgreen and his colleagues said there was an "urgent need" to isolate and study the various ways people engage with screens while sitting. A growing body of evidence suggests scrolling TikTok, Twitter, Facebook and Instagram can sap attention spans and harm overall mental health. Young adults who took just a weeklong break from social media platforms reported a drop in depressive symptoms, insomnia and anxiety.
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