Cholesterol link in Alzheimer's study

A popular cholesterol-lowering drug, Lipitor, is being studied in the United States as a treatment for Alzheimer's disease.

"We have found that individuals with high cholesterol levels have an increased risk of developing Alzheimer's," said Dr Larry Sparks, senior scientist at the Sun Health Research Institute in Sun City, Arizona.

"We believe cholesterol from the blood, over a long period of time, also gets in the brain, where it promotes the production of a toxin that causes the disorder."

Dr Sparks said he believed that people who were healthy enough not to succumb to heart disease, but had high cholesterol, still faced the risk of future dementia.

Alzheimer's, the most common form of dementia, affects an estimated four million Americans. The number is expected to rise sharply in line with an ageing population.

The degenerative brain disease is caused by a buildup in the brain of sticky plaques made up of deposits of a protein called amyloid beta, which is toxic to cells.

Dr Sparks said he chose Lipitor, made by Pfizer, over other drugs in the same class, which included Merck's Zocor and Bristol-Myers Squibb's Pravachol, because it offered the best safety profile.

"This is an investigator-initiated study. I chose Lipitor because it doesn't cross the blood-brain barrier."

He said a cholesterol-lowering drug that directly penetrated the brain could present a danger to patients since it could inhibit cholesterol synthesis within the brain.

"The idea is to make the blood act like a sponge that passively draws out the cholesterol," Dr Sparks said.

The Institute for the Study of Ageing, in New York, and Pfizer are partly paying for the research.

- REUTERS