Caloric intake and the risk of Alzheimer disease.

BACKGROUND Diet may play a role in Alzheimer disease (AD). OBJECTIVE To examine the association between caloric intake and AD. METHODS Elderly individuals free of dementia at baseline (N = 980) were followed for a mean of 4 years. Daily intake of calories, carbohydrates, fats, and protein were recalled using a semiquantitative food frequency questionnaire administered between the baseline and first follow-up visits. Proportional hazards models were used to examine the associations of quartiles of intake and incident AD, adjusting for confounders. RESULTS There were 242 incident cases of AD during 4023 years of follow-up (6 cases per 100 person-years). Compared with individuals in the lowest quartile of caloric intake, those in the highest quartile had an increased risk of AD (hazard ratio, 1.5; 95% confidence interval [CI], 1.0-2.2). Among individuals with the apolipoprotein E epsilon4 allele, the hazard ratios of AD for the highest quartiles of calorie and fat intake were 2.3 (95% CI, 1.1-4.7) and 2.3 (95% CI, 1.1-4.9), respectively, compared with the lowest quartiles. The hazard ratios of AD for the highest quartiles of calorie and fat intake compared with the lowest quartiles in individuals without the apolipoprotein E epsilon4 allele were close to 1 and were not statistically significant (P =.83 and P =.61, respectively). CONCLUSION Higher intake of calories and fats may be associated with higher risk of AD in individuals carrying the apolipoprotein E epsilon4 allele.