The breakdown of myelin, a sheet of fat that insulates nerves and helps speed messages through the brain, appears to be a key contributor to the onset of Alzheimer’s disease, a study published on Monday said.Researchers at UCLA, who reported their findings in the journal Archives of General Psychiatry, used magnetic resonance imaging to assess the breakdown of myelin in 104 healthy adults between the ages of 55 and 75.They found the severity and rate of myelin breakdown was correlated with the type of APOE, or apolipoprotein-E, gene a person had. Previous research has shown APOE status to be the second biggest risk factor for the disease after aging, with a version called APOE-4 putting persons at highest risk.The study found the breakdown of myelin, a natural part of the aging process, proceeded most rapidly for those with APOE-4, less so for those with APOE-3 and most slowly for those with APOE-2. APOE-2 is thought to offer some protection from Alzheimer’s, while APOE-3 is seen as neutral.
