A prospective UK cohort study suggested that high levels of cognitively passive sedentary behaviors (SB) were associated with increased risk of dementia, while cognitively active SB were associated with reduced risk of dementia. The study included 146,651 participants who were 60 years or older (mean age 64.59 years) and did not have a diagnosis of dementia. A total of 3,507 individuals were diagnosed with all-cause dementia over a mean follow-up of 11.87 years. In models adjusted for a wide range of covariates, including time spent in physical activity (PA), time spent watching TV was associated with increased risk of incident dementia (HR 1.24) and time spent using a computer was associated with decreased risk of incident dementia (HR 0.85). In joint associations with PA, the associations remained significantly at all PA levels. The findings are consistent with previous studies and suggest that reducing time spent in cognitively passive SB (i.e., TV time) and increasing time spent in cognitively active SB (i.e., computer use, gaming, reading, etc.) may be effective for reducing risk of dementia regardless of PA. It is known that SB is associated with increased risk of mortality, the development of cardiometabolic disease, and cognitive and structural brain aging. Source: https://www.pnas.org/
