Dietary fat intake and the risk of incident dementia in the Rotterdam study

TLDR

High saturated fat and cholesterol intake is linked to cardiovascular disease, which is associated with dementia. The study examined the relationship between dietary fat intake and incident dementia in participants aged 55 years or older in the Rotterdam Study. Dietary intake was measured in 5,386 nondemented participants with a semiquantitative food‑frequency questionnaire, followed for an average of 2.1 years, with dementia screened by a three‑step protocol and risk estimated using logistic regression. Higher total fat, saturated fat, and cholesterol intake increased dementia risk—especially vascular dementia—while fish consumption was inversely associated, particularly with Alzheimer’s disease.

Abstract

Abstract A high intake of saturated fat and cholesterol and a low intake of polyunsaturated fatty acids have been related to an increased risk of cardiovascular disease. Cardiovascular disease has been associated with dementia. We investigated the association between fat intake and incident dementia among participants, age 55 years or older, from the population‐based prospective Rotterdam Study. Food intake of 5,386 nondemented participants was assessed at baseline with a semiquantitative food‐frequency questionnaire. At baseline and after an average of 2.1 years of follow‐up, we screened for dementia with a three‐step protocol that included a clinical examination. The risk of dementia at follow‐up ( RR [95% CI]) was assessed with logistic regression. After adjustment for age, sex, education, and energy intake, high intakes of the following nutrients were associated with an increased risk of dementia: total fat ( RR = 2.4 [1.1–5.2]), saturated fat ( RR = 1.9 [0.9–4.0]), and cholesterol ( RR = 1.7 [0.9–3.2]). Dementia with a vascular component was most strongly related to total fat and saturated fat. Fish consumption, an important source of n‐3 polyunsaturated fatty acids, was inversely related to incident dementia ( RR = 0.4 [0.2–0.9]), and in particular to Alzheimer's disease ( RR = 0.3 [0.1–0.9]). This study suggests that a high saturated fat and cholesterol intake increases the risk of dementia, whereas fish consumption may decrease this risk.