Associations between sedentary behaviours and cognitive function: cross-sectional and prospective findings from the UK Biobank

We investigate the cross-sectional and prospective associations between different sedentary behaviours and cognitive function in a large sample of UK Biobank adults. Baseline data were available on 502,643 participants (years 2006-2010). Cognitive tests included prospective memory [n=171,585 (baseline only)], visual-spatial memory [round 1 (n=483,832); round 2 (n=482,762)], fluid intelligence [n=165,492], and short-term numeric memory [n=50,370]. After a mean period of 5.3-years, between 12,091 and 114,373 participants also provided follow-up cognitive data. Sedentary behaviours [Television (TV) viewing, driving, and non-occupational computer use time] were measured at baseline. At baseline, both TV viewing and driving time were inversely associated with cognitive function across all outcomes [e.g. for each additional hour spent watching TV, the total number of correct answers in the fluid intelligence test was 0.15 (99% confidence interval: 0.14, 0.16) lower]. Computer use time was positively associated with cognitive function across all outcomes. Both TV viewing and driving time at baseline were positively associated with the odds of having cognitive decline at follow-up across most outcomes. Conversely, computer use time at baseline was inversely associated with the odds of having cognitive decline at follow-up across most outcomes. This study supports health policies designed to reduce TV viewing and driving in adults.