Enriched environment at work and the incidence of dementia: results of the Leipzig longitudinal study of the aged (LEILA 75+).

Background: The high incidence of cognitive impairments in the aging population together with the challenges it imposes on health systems raise the question of what effect working life has on cognitive abilities. Animal models have demonstrated that so called enriched environments protect against neurodegenerative diseases, such as dementia. The aim was to investigate the impact of enriched environment at work on the incidence of dementia.

Methods: The Leipzig Longitudinal Study of the Aged (LEILA 75+) is an ongoing representative population cohort study that examines cognitive functioning and dementia in individuals aged 75 years and older. The participants' occupational information was matched to O*NET SOC codes and the relevant job descriptors were used to create occupational context indices describing enriched environment at work.

Results: Results of logistic regression modeling suggest that a higher level of the index Executive was associated with a lower risk of incident dementia (odds ratio  = 0.61, 95% confidence interval  = 0.47-0.79, p<0.001). Adjustment for various confounders did not alter the association. The cognitive stimulation indices were only significant in univariate analysis. The Novelty-index remained non-significant.

Conclusions: The results suggest that occupational contexts enriched with independent planning/performance of work tasks might decrease the risk of developing dementia. A protective effect of enriched environment at work in general, namely high cognitive stimulation or confrontation with new tasks, could not be confirmed by the results.