Cholesterol and Alzheimer's disease: a still poorly understood correlation.

A large amount of evidence suggests a pathogenic link between cholesterol homeostasis dysregulation and Alzheimer's disease (AD). In cell culture systems, the production of amyloid-β (Aβ) is modulated by cholesterol, and studies on animal models have consistently demonstrated that hypercholesterolemia is associated with an increased deposition of cerebral Aβ peptides. Consequently, a number of epidemiological studies have examined the effects of cholesterol-lowering drugs (i.e., statins) in the prevention and the treatment of AD. However, while retrospective studies suggested a potential benefit of statin therapy, clinical trials produced inconsistent results. Here, we summarize the main findings from in vitro and in vivo research where the correlation between cholesterol and the neurodegenerative disorder was investigated. Recognition of this correlation could be an important step forward for our understanding of AD pathogenesis and, possibly, for the development of new therapeutic strategies.