The brain relies on astrocytes for cholesterol transport, which may be impaired by insulin resistance and the APOE4 allele.

“what I saw when I kind of dug into this and was writing a section on the book was that a belief before is this is molecules is even with approaching the transverse cholesterol from the astrocyte to the neurons in the brain i merrily the brain can't really make its own cholesterol so it has to make it in the answer site and the answer site has to give to the glial cells or the neurons”