Healthy lifestyle and the risk of Alzheimer's dementia: Findings from two longitudinal studies

Objective

To quantify the impact of a healthy lifestyle on the risk of Alzheimer's dementia.

Methods

Using data from the Chicago Health and Aging Project (CHAP n=1,845) and the Rush Memory and Aging Project (MAP n=920), we defined a healthy lifestyle score on the basis of non-smoking, >=150 min/week moderate/vigorous intensity physical activity, light-to-moderate alcohol consumption, high-quality MIND diet (upper 40%), and engagement in late-life cognitive activities (upper 40%), giving an overall score ranging from 0 to 5. Cox proportional hazard models were used for each cohort to estimate the hazard ratio (HR) and 95% confidence interval (95%CI) of the lifestyle score with Alzheimer’s dementia and a random effect meta-analysis was used to pool the results.

Results

During a median follow-up of 5.8 years in CHAP and 6.0 years in MAP, 379 and 229 participants, respectively had incident Alzheimer's dementia. In multivariable-adjusted models, the pooled HR (95%CI) of Alzheimer’s dementia across two cohorts was 0.73 (95%CI, 0.66-0.80) per each additional healthy lifestyle factor. Compared to participants with 0-1 healthy lifestyle factor, the risk of Alzheimer’s dementia was 37% lower (pooled HR 0.63; 95%CI, 0.47-0.84) in those with 2-3 healthy lifestyle factors, and 60% lower (pooled HR 0.40; 95%CI, 0.28-0.56) in those with 4-5 healthy lifestyle factors. 

Conclusion

A healthy lifestyle as a composite score is associated with a substantially lower risk of Alzheimer’s dementia.