Fatty acids of plasma lipids, red cells and platelets in Alzheimer's disease and vascular dementia.

Fatty acids of plasma lipids, red cells and platelets were analyzed from 38 demented patients (age 53-88 years), comprising 11 patients with Alzheimer's disease (AD), 19 with multi-infarct dementia (MID) and 8 with probable vascular dementia (PVD). The mean age, body mass index, duration of dementia and content of triglycerides, total cholesterol and HDL-cholesterol in plasma were similar in AD and MID. The patients with PVD were older. As compared to AD, in MID and PVD the linoleic acid (LA) and other n-6 and n-3 polyunsaturated fatty acids (PUFA) were significantly lower in red cells and tended to be lower also in serum triglycerides, cholesterol esters (CHE) and phospholipids (PL), and platelets. The LA content of red cells was significantly correlated with that of serum CHE and PL, and n-6 PUFA (including arachidonic acid) of red cells. The low LA content of red cells was associated with old age, coronary heart disease and heart failure, but not with the severity of dementia.