脂質栄養：脂質と認知症－日本脂質栄養学会第16回大会モリス博士基調講演の記録－

A growing body of evidence from animal and human studies links dietary fat composition, blood lipids, and cholesterol to the development of dementia.
Cholesterol is central to the process of Alzheimer's disease. The primary genetic risk factor for late onset Alzheimer's disease is the apolipoprotein E (APOE)-e4 allele. Apolipoprotein E is involved in cholesterol transport. The composition of dietary fats affects levels of blood cholesterol and other circulating lipids.
Of the different types of dietary fats, saturated and trans fats increase blood LDL-cholesterol. Blood cholesterol level and a hypercholesterolemic diet have been associated with cognitive decline, Alzheimer's disease and brain neuropathology. Recent studies in animal models and in humans suggest that the deleterious effects of these hypercholesterolemic diets on the brain may be far worse in the presence of dietary copper. The n-3 class of polyunsaturated fat (PUFA) obtained from marine and plant sources has been associated with slower rate of cognitive decline and lower risk of developing Alzheimer's disease. The n-3 PUFA, docosahexaenoic acid (DHA) has been targeted as particularly important for brain function, and is the primary lipid in the most metabolically active areas of the brain. Several randomized clinical trials are currently underway to test the effects of n-3 fatty acid supplementation on cognitive decline and the development of Alzheimer's disease.