Statins may protect against Alzheimer's-U.S. study

By Will Dunham

WASHINGTON, July 28 (Reuters) - Cholesterol-lowering drugs called statins may help protect against Alzheimer's disease and other types of dementia, according to a U.S. study published on Monday.

People who took statins were half as likely as those who did not take them to develop Alzheimer's disease, vascular dementia or any other form of dementia, researchers reported in the journal Neurology.

"Statins may have a benefit for preventing dementia and cognitive impairment," Mary Haan, a professor of epidemiology at the University of Michigan School of Public Health who led the study, said in a telephone interview.

The findings were the latest to indicate that this widely used class of drugs may provide health benefits beyond lowering blood cholesterol levels and reducing heart disease risk.

Haan's team studied 1,674 elderly Mexican Americans living in California. More than a quarter were taking statins. They did not have any dementia at the beginning of the study and were followed for an average of five years.

The researchers said they accounted for several other risk factors for dementia including education, smoking, diabetes, stroke and genetic predisposition, and still found that people taking statins had only half the risk of developing dementia.

Not all the people in the study were taking the same type of statins, but the most commonly taken one was Pfizer Inc's (PFE.N) Lipitor, also called atorvastatin, Haan said. The study did not determine if one type of statin was better than others in lowering dementia risk, Haan added.

It also did not examine statins as a treatment for people who already had Alzheimer's disease or some other dementia.

BROAD EFFECTS

Statins work by lowering the production of cholesterol by the liver, and are most effective at reducing low-density lipoprotein, or LDL, the so-called bad cholesterol.

Statins are known to help ward off heart attack and stroke. Studies also have indicated statins may offer other benefits including reducing the risk of getting cancer and lowering the risk of death from influenza, pneumonia and smoking.

Alzheimer's disease is the most common form of dementia in the elderly, and vascular dementia -- loss of brain function thanks to a series of small strokes -- is second.

Haan said it is unclear how statins may guard against dementia, but it could be their cholesterol-lowering properties, their effect on inflammation in the body, or their influence on the hormone insulin.

"This is an encouraging development in the fight against dementia," Rebecca Wood, who heads the British-based Alzheimer's Research Trust charity, said in a statement.

"It adds to previous research into the potential benefits of statins in reducing memory loss. However, people should not take statins unless medically advised to do as, as side effects can be unpleasant," Wood added.