Fat intake at midlife and risk of dementia and Alzheimer's disease: A population-based study

Background: Lifestyle and vascular factors have been linked to dementia and Alzheimer's disease ( AD), but the role of dietary fats in the development of dementia is less clear. Methods: Participants were derived from random, population-based samples initially studied in midlife ( 1972, 1977, 1982, or 1987). Fat intake from spreads and milk products was assessed using a structured questionnaire and an interview. After an average follow-up of 21 years, a total of 1,449 (73%) individuals aged 65 - 80 years participated in the re-examination in 1998. Altogether 117 persons had dementia. Results: Moderate intake of polyunsaturated fats at midlife decreased the risk of dementia even after adjustment for demographic variables, other subtypes of fats, vascular risk factors and disorders, and apolipoprotein E ( ApoE) genotype ( OR 0.40, CI 0.17 - 0.94 for the 2nd quartile vs. 1st quartile), whereas saturated fat intake was associated with an increased risk ( OR 2.45, CI 1.10 - 5.47 for the 2nd quartile). The associations were seen only among the ApoE epsilon 4 carriers. Conclusions: Moderate intake of unsaturated fats at midlife is protective, whereas a moderate intake of saturated fats may increase the risk of dementia and AD, especially among ApoE epsilon 4 carriers. Thus, dietary interventions may potentially modify the risk of dementia, particularly among genetically susceptible individuals. Copyright (C) 2006 S. Karger AG, Basel.