Cholesterol May be Bellwether for Alzheimer's

Now you have even more incentive to get that high cholesterol down to a healthy level: It may be contributing to Alzheimer's later in life.

Researchers have for years known of a connection between vascular disease and Alzheimer's. Vascular dementia, in fact, is among the most common forms of age-related brain disease resulting in a loss of memory and cognitive skills.

But this week a recently released study showed cholesterol may actually be a contributing factor to the build up of the beta amyloid protein that is a hallmark of Alzheimer's disease, which is responsible for the majority of all age-related dementia.

"Amyloid deposition is important because it is widely believed by scientists to be a key event that initiates a chain of events that eventually, years later, results in the dementia of Alzheimer's disease," Professor Bruce Reed of the UC Davis Alzheimer's Research Center told a Reuters reporter.

Using cholesterol tests and PET brain scans of 74 elderly people with normal functionality or mild cognitive impairment, the reserachers discovered those with higher levels of the "bad" LDL cholesterol and lower levels of "good" HDL cholesterol also had higher levels of amyloid in the brain.

"Cholesterol in blood and cholesterol in brain are separate 'pools,' walled off from one another by the blood brain barrier. We measured cholesterol in blood. So that is one question that needs to be answered - how do cholesterol levels in blood and in brain influence each other," Reed said.

"And in the brain, it is not entirely understood how changing cholesterol levels might reduce amyloid deposition. We are very interested in the idea that higher HDL ('good') cholesterol levels may help the brain more efficiently clear the toxic amyloid at an early stage," Reed said.

"If those questions were understood we could begin to think about how to change cholesterol levels so as to prevent the buildup of amyloid," he added.