title: Caffeine intake is associated with a lower risk of cognitive decline: a cohort study from Portugal.
abstract: Alzheimer's disease has emerged in recent decades as a major health problem and the role of lifestyles in the modulation of risk has been increasingly recognized. Recent epidemiological studies suggest a protective effect for caffeine intake in dementia. We aimed to quantify the association between caffeine dietary intake and cognitive decline, in a cohort of adults living in Porto. A cohort of 648 subjects aged > or =65 years was recruited between 1999-2003. Follow-up evaluation (2005-2008) was carried out on 58.2% of the eligible participants and 10.9% were deceased. Caffeine exposure in the year preceding baseline evaluation was assessed with a validated food frequency questionnaire. Cognitive evaluation consisted of baseline and follow-up Mini-Mental State Examination (MMSE). Cognitive decline was defined by a decrease > or =2 points in the MMSE score between evaluations. Relative risk (RR) and 95% confidence interval (95%CI) estimates adjusted for age, education, smoking, alcohol drinking, body mass index, hypertension, and diabetes were computed using Poisson regression. Caffeine intake (> 62 mg/day [3rd third] vs. < 22 mg/day [1st third]) was associated with a lower risk of cognitive decline in women (RR=0.49, 95%CI 0.24-0.97), but not significantly in men (RR=0.65, 95%CI 0.27-1.54). Our study confirms the negative association between caffeine and cognitive decline in women.
authors.affiliation: Department of Hygiene and Epidemiology, Porto University Medical School and Institute of Public Health, University of Porto (ISPUP), Porto, Portugal. catarinasantos@portugalmail.pt
authors.forename: Catarina
authors.initials: C
authors.lastname: Santos
authors.forename: Nuno
authors.initials: N
authors.lastname: Lunet
authors.forename: Ana
authors.initials: A
authors.lastname: Azevedo
authors.forename: Alexandre
authors.initials: A
authors.lastname: de Mendonça
authors.forename: Karen
authors.initials: K
authors.lastname: Ritchie
authors.forename: Henrique
authors.initials: H
authors.lastname: Barros
mesh_terms: D000368:Aged; D002110:Caffeine / Q000008:administration & dosage*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage*; D003069:Coffee / Q000378:metabolism*; D003072:Cognition Disorders / Q000453:epidemiology* / Q000378:metabolism; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D009483:Neuropsychological Tests; D011174:Portugal / Q000453:epidemiology; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D000697:Central Nervous System Stimulants; D003069:Coffee; D002110:Caffeine