Physical and Mental Activities Lower Dementia Risk, Despite Genetic Vulnerability

Physical and mental activity patterns are associated with risk of developing multiple types of dementia, according to study findings published in Neurology.

Dementia is associated with loss of independence and disability among older adults. Although several risk factors have been associated, it remains unclear whether there are additional modifiable behaviors that may affect dementia outcomes.

Data for this study were sourced from the UK Biobank. Self-reported physical and mental activities were evaluated for their relationship with dementia risk through 2019. Physical activities for 21 items were reported using the International Physical Activity Questionnaire (IPAQ) and mental activities were evaluated via education level, social contact, and use of an electronic device. Dementia was defined using International Classification of Diseases coding and dementia susceptibility using polygenic risk score, apolipoprotein E (APOE) genotype, and family history.

The study population (N=501,376) was aged mean 56.53 years at recruitment and 45.60% were men.

Over a mean follow-up of 10.66 years, 5185 had been diagnosed with dementia. Among cases, 1561 had Alzheimer disease, 803 vascular dementia, and 2697 other dementia.

Most physical activities associated with decreased risk for dementia.

Among the physical activities, five principal components accounted for 50.2% of the total variance, in which vigorous and other exercise, housework-related activity, transport-related activity, job-related activity, and walking for pleasure were the activities most to least related with dementia, respectively.

Stratified by genetic risk, adhering to vigorous physical activity was associated with decreased dementia risk among both those with high (Hazard ratio [HR], 0.68; 95% CI, 0.57-0.79) and low (HR, 0.64; 95% CI, 0.52-0.77) genetic risk. Vigorous physical activity decreased risk for APOE carriers (HR, 0.63; 95% CI, 0.54-0.72) and non-carriers (HR, 0.68; 95% CI, 0.59-0.78), and those with a family history (HR, 0.64; 95% CI, 0.52-0.79) and without (HR, 0.69; 95% CI, 0.60-0.78).

Higher risk for dementia was observed for visiting a pub or social club (HR, 1.07; 95% CI, 0.99-1.15) and watching television (HR, 1.07; 95% CI, 1.05-1.09). Lower risk was associated with family and friend visits (HR, 0.66; 95% CI, 0.56-0.77) and other group activities (HR, 0.91; 95% CI, 0.85-0.98).

In the principal component analysis for mental-related activities, 52.5% of the variance associated with pub or social club visit, watching television, attending a group activity or educational class, and family or friend visit.

Stratified by type of dementia, similar relationships with physical and mental activities were observed.

The major limitation of this study was the reliance on self-reported activities.

“Such associations are independent of disease susceptibility, highlighting the potential of these physical and mental activity patterns, as effective interventions, in the primary prevention of dementia,” the researchers concluded about the association between activity patterns and risk for multiple types of dementia.

Reference

Zhu J, Ge F, Zeng Y, et al. Physical and mental activity, disease susceptibility, and risk of dementia: a prospective cohort study based on UK Biobank. Neurology. Published online July 27, 2022. doi:10.1212/WNL.0000000000200701