Relative amounts of "good" and "bad" cholesterol in the blood influence the build-up of harmful protein deposits in the brain called beta amyloid plaques, a study found.
The discovery may explain the well-known correlation between raised levels of cholesterol and an increased risk of developing Alzheimer's.
Experts draw a sharp distinction between "good" cholesterol, or high density lipoprotein (HDL) and its evil twin - low density lipoprotein (LDL).
While high levels of LDL can lead to narrowed arteries and heart disease, HDL is protective. The new US research suggests the effects the two kinds of cholesterol have on the heart may be mirrored in the brain.