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.