Occasions for laughter and dementia risk: findings from a six-year cohort study

概要

[目的(Purpose)]
Currently, there is little evidence on the relationship between laughter and the risk of dementia, and since laughter is mainly a social behavior, we aimed to examine the association between various occasions for laughter and the risk of dementia in Japanese older adults.

[方法ならびに成績(Methods/Results)]
We draw upon a 6-year follow-up data from the Japan Gerontological Evaluation Study, including 12,165 independent older adults aged 65 years and over. Occasions for laughter were assessed using a questionnaire, while dementia was diagnosed using the standardized dementia scale of the long-term care insurance system in Japan. Cox proportional hazards models were estimated, yielding hazard ratios (HRs)and 95% confidence intervals (Cis).

The multivariable hazard ratio of dementia incidence for all participants in the high versus a low variety of occasions for laughter was 0.84 (95% confidence interval: 0.72-0.98, p for trend<0.001). A greater variety of occasions for laughter was associated with a lower risk of dementia 0.78 (95% confidence interval: 0.63- 0.96, p for trend<0.001) among women, but less pronounced for men with significant associations only for the medium group. Laughing during conversations with friends, communicating with children or grandchildren, and listening to the radio was primarily associated with decreased risk. Various occasions or events for laughter were marginally associated with a decreased risk of dementia among women while laughing while accompanied by friends was associated with a lower risk among men.

[総括(Conclusion)]
There are some occasions for laughter in individual and social settings associating with a reduced risk of dementia in this cohort. Our study highlights the important role of positive psychology and psychosocial factors in delaying dementia risk in older adults.