Their 'theories' are just that, unproven hypothesis. Regards the liver and heart, yea i have no problem with 90% of the cholesterol made by the liver - i guess somehow that number correlates with 30% of the body's cholesterol 'deposits' winding up as brain fatty tissue. I imagine the 'Experts' completely disregard it being necessary for the brain - if they were even taught/ told it in detail, and focus on the balance between good and bad cholesterol 'lining the arteries' as the determining factor.