Soda consumption and risk of dementia: The Northern Manhattan study

BackgroundSoda consumption is associated with vascular risk, but little is known about soda in relation to dementia.ObjectiveWe hypothesized that both regular and diet soda consumption were associated with increased dementia risk.MethodsWe utilized data from longitudinal population-based Northern Manhattan Study. Regular and diet soda consumption were assessed by food frequency questionnaire. Dementia was adjudicated during follow-up after a series of comprehensive neuropsychological and functional assessments. Cox proportional hazards models examined the associations between regular and diet soda consumption and dementia risk, adjusting for demographics and vascular risk factors.ResultsOf 947 dementia-free participants (mean baseline age=64 ± 8 years, 41% men, 64% Hispanic, 16% non-Hispanic White, 18% non-Hispanic Black), 20% developed dementia during follow-up, 4.8% drank regular soda >1/day and 2.3% drank diet soda >1/day. Diet soda was associated with increased dementia risk (per diet soda/day aIRR=1.39, 95% CI = 1.09-1.75), specifically among non-Hispanic White and Black participants but not among Hispanics. Those who consumed >1 diet soda per day had a 4.15- fold increased risk versus ≤1/day (95% CI = 1.81-9.49), adjusting for sociodemographics and behavioral risk factors. The association was not apparent after excluding those with obesity or diabetes, highlighting a potential for reverse causation. Although no significant association was observed between regular soda consumption and dementia, a nonstatistically significant trend was observed (unadjusted p = 0.07).ConclusionsThe results support a potential increased dementia risk associated with frequent consumption of diet soda. Further study is needed into the impacts of obesity and diabetes.