Research published this week from the Technical University of Munich explores how the degredation of myelin leaves a destructive cholesterol residue in the brain, which increases an inflammatory response and blocks myelin regeneration. It appears that with age, the process of transporting cholesterol out of the brain becomes less efficient. (Important to state that this research was done on a mouse model of MS.)
"Myelin contains a very high amount of cholesterol," explains Prof. Simons. "When myelin is destroyed, the cholesterol released has to be removed from the tissue." This is performed by microglia and macrophages, also referred to as phagocytes. They take up the damaged myelin, digest it and transport the non-digestible remainder, such as cholesterol, out of the cell by transport molecules. However, if too much cholesterol accumulates in the cell, cholesterol can forms needle-shaped crystals, which cause damage the cell. Using a mouse model, Simons and his team showed the devastating impact of the crystalline cholesterol: It activates the so-called inflammasome in phagocytes, which results in the release of inflammatory mediators, attracting even more immune cells. "Very similar problems occur in arteriosclerosis, however not in the brain tissue, but in blood vessels," says Simons.
Although cholesterol synthesis in the brain is considered a different process than cholesterol synthesis in the rest of the body, lower plasma levels of HDL cholesterol have been found to be related to MS. Cardiovascular researchers have been looking at this fact, in relation to the heart brain connection.
HDL plasma levels have also been associated with other neurodegenerative diseases such as multiple sclerosis (MS). Patients in the acute phase MS have been reported to have lower HDL-C levels compared with those in the remission phase, and they show a higher probability of developing acute inflammatory lesions (assessed by MRI). Moreover, HDL inhibits cytokine-induced expression of adhesion molecules in endothelial cells.
Why are HDL levels important? Because HDL, also known as "good cholesterol", contains the transport protein ApoA1---needed to take cholesterol out of the blood and tissue.
Here's more research on low levels of ApoA1 found to be linked to MS severity. The lower HDL
ApoA1 plasma levels, the more severe the disease.
ApoA1 was reduced by approximately 25% in patients with relapsing-remitting MS, 50% in those with secondary progressive MS, and 75% in patients with primary progressive MS, the most severe form of the disease. link
Here's a whole blog post from 2013 on "Good" cholesterol and your brain
7. Check your vitamin D, magnesium, calcium and zinc levels--make sure they are in balance.