Participation in Cognitively Stimulating Activities and Risk of Incident Alzheimer Disease

TLDR

Frequent engagement in cognitively stimulating activities has been proposed to lower Alzheimer disease risk, yet prospective evidence has been lacking. The study aimed to determine whether regular participation in cognitive activities is linked to a reduced incidence of Alzheimer disease. Researchers conducted a longitudinal cohort study of 801 older Catholic clergy, assessing baseline frequency of activities such as reading, and followed participants for an average of 4.5 years, diagnosing Alzheimer disease via neurologist evaluation and tracking changes in global and specific cognitive measures. During follow‑up, 111 participants developed Alzheimer disease, and each one‑point increase in activity score corresponded to a 33% lower risk (HR 0.67) and a 47% slower decline in global cognition, 60% in working memory, and 30% in perceptual speed.

Abstract

ContextFrequent participation in cognitively stimulating activities has been hypothesized to reduce risk of Alzheimer disease (AD), but prospective data regarding an association are lacking.ObjectiveTo test the hypothesis that frequent participation in cognitive activities is associated with a reduced risk of AD.DesignLongitudinal cohort study with baseline evaluations performed between January 1994 and July 2001 and mean follow-up of 4.5 years.Participants and SettingA total of 801 older Catholic nuns, priests, and brothers without dementia at enrollment, recruited from 40 groups across the United States. At baseline, they rated frequency of participation in common cognitive activities (eg, reading a newspaper), from which a previously validated composite measure of cognitive activity frequency was derived.Main Outcome MeasuresClinical diagnosis of AD by a board-certified neurologist using National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association criteria and change in global and specific measures of cognitive function, compared by cognitive activity score at baseline.ResultsBaseline scores on the composite measure of cognitive activity ranged from 1.57 to 4.71 (mean, 3.57; SD, 0.55), with higher scores indicating more frequent activity. During an average of 4.5 years of follow-up, 111 persons developed AD. In a proportional hazards model that controlled for age, sex, and education, a 1-point increase in cognitive activity score was associated with a 33% reduction in risk of AD (hazard ratio, 0.67; 95% confidence interval, 0.49-0.92). Results were comparable when persons with memory impairment at baseline were excluded and when terms for the apolipoprotein E ∊4 allele and other medical conditions were added. In random-effects models that controlled for age, sex, education, and baseline level of cognitive function, a 1-point increase in cognitive activity was associated with reduced decline in global cognition (by 47%), working memory (by 60%), and perceptual speed (by 30%).ConclusionThese results suggest that frequent participation in cognitively stimulating activities is associated with reduced risk of AD.