Physical and mental demands of work associated with dementia risk in later life.

backgroundWork occupies a significant portion of adult life, and both cognitive stimulation and physical activity have been suggested as factors that may lower dementia risk in later life.

objectivesTo examine the association between mental and physical demands at work and the risk of dementia.

designA cohort study.

settingSeven selected districts in Taiwan, covering both urban and rural areas.

participants4,083 community-dwelling healthy adults aged 55 and older from the Healthy Aging Longitudinal Study. MEASUREMENTS: A job matrix of work conditions by occupation was generated using data from a representative national survey. Mental demands were assessed by job control and psychological demands from the Job Content Questionnaire, as well as skill levels. Physical demands were assessed using a 4-point Likert scale and dichotomized into high and low levels. Dementia diagnoses were identified based on physician diagnosis registered in the National Health Insurance database.

resultsOver a follow-up period of 6.2 years, 513 participants were diagnosed with dementia. After adjusting for confounding factors in cox regression models, high (vs. low) job control, high -skilled jobs (vs. low), and high physical demands (vs. low) were associated with a reduced future risk of dementia. Psychological demands were not associated with dementia risk.

conclusionsGreater utilization of job skills and engagement in physically demanding activities at work may help mitigate the risk of developing dementia. The effects of different dimensions of psychological demands on cognitive health warrant further investigation.