Increased Physical Activity Does Not Lower Dementia Risk

Some observational studies have suggested that increased physical activity is linked to lower rates of cognitive decline, but exercise has failed to produce a cognitive benefit in intervention studies. This prospective 28-year study conducted in a large British cohort of civil servants measured physical activity at seven time points and assessed cognitive function up to four times.

There was no association between level of physical activity and subsequent 15-year cognitive decline nor between physical activity and risk for dementia over the 28-year follow-up period. Until 10 years before diagnosis, physical activity levels were the same in participants who did and did not develop dementia. At 9 years before diagnosis, a decline in physical a…