Serum Cholesterol, the Brain, and Cognitive Functioning

Cholesterol plays a well-known role in atherosclerosis, yet it is an important nutrient and is found in every cell in the human body. In this chapter we consider cholesterol's potential relationships to aspects of cognitive functioning. We review studies of (a) healthy young adults; (b) older individuals with and without cognitive impairment or Alzheimer's disease (AD); and (c) cholesterol's relationship to stroke, a major medical cause of overt neurological deWcits. Following a brief overview of cholesterol, related fats, and lipid metabolism, each literature is presented and followed by a discussion of potential biologic mechanisms. We consider only normative variability in serum cholesterol concentration. The rare, inherited disorders of lipid metabolism can be associated with central nervous system (CNS) pathology but are not included in this review.