Thematic review series: brain Lipids. Cholesterol metabolism in the central nervous system during early development and in the mature animal.
Level 5 - mechanism / opinion, no new human data
Narrative review of physiological mechanisms without systematic search methodology or original human experimental data.
PubMed 15254070 · doi:10.1194/jlr.R400004-JLR200
What was done
This narrative review summarizes evidence on cholesterol metabolism in the central nervous system (CNS) across early development and adulthood, focusing on tissue distribution, local synthesis, and elimination pathways.
What was found
The human CNS contains an unesterified cholesterol concentration of approximately 23 mg/g, representing 23% of total whole-body sterol while accounting for only 2.1% of body weight. CNS cholesterol originates exclusively from local de novo synthesis, with no evidence for net transfer from the blood. In adults, synthesis exceeds structural requirements, requiring clearance through at least two excretory pathways, one involving 24(S)-hydroxycholesterol formation. Whether plasma cholesterol changes influence CNS sterol metabolism, cognitive function, or dementia risk remains uncertain.
Why it matters
It establishes that the central nervous system maintains an autonomous cholesterol pool insulated from direct net sterol transfer from systemic circulation.
Limits
This is a narrative review with no systematic search methodology or original clinical data. Abstract reports no quantitative kinetic rates, and associations with plasma cholesterol, cognitive function, or dementia remain unproven.
Cited by
- supports 25% of the total cholesterol in the human body is located in the brain.