Study: Statins tied to fewer signs of dementia

The cholesterol-reducing drugs are being studied for their unintended benefits.

TORONTO GLOBE AND MAIL

A popular cholesterol-lowering drug may also stall the onset of Alzheimer’s disease, a new study has found.

The research, published Tuesday in the medical journal Neurology, shows that people who took statins — a class of drugs that includes Lipitor and Zocor — had fewer signs of the degenerative brain disorder compared with those not given the drugs.

Autopsies conducted on 110 brains donated by subjects aged 65 to 79 showed that statin users had significantly fewer of the brain changes typically linked with Alzheimer’s disease, including tangles of dead neurons and a buildup of plaque.

“I won’t say that I expected to get this finding, but it really has caused us to rethink the role of these drugs in brain aging in general,” said Eric B. Larson, study co-author and executive director of the Group Health Center for Health Studies in Seattle.

The study is part of a growing body of research looking at potential benefits of statins in illnesses other than heart disease, such as osteoporosis and cancer.

Commonly prescribed

Statins are “so commonly used that people are studying [them] for other uses,” said Louise Pilote, director of internal medicine at McGill University, who has been studying the effects of statin use for five years, including how the drugs affect men and women differently.

Statins are believed to work by lowering low-density lipoprotein — the so-called bad cholesterol — which in turn prevents progression of dangerous plaque buildup in arteries, which can lead to a heart attack.

The use of statins has “skyrocketed” since the mid-1990s, as lowering bad cholesterol has become one of the top strategies for preventing heart disease, Dr. Pilote said. In Quebec, British Columbia and Ontario, up to 80 percent of patients who have had a heart attack are prescribed statins, she said.

Scientists have begun to look at how the drugs affect people in unintended ways, particularly when it comes to diseases associated with aging. “Blood vessels are everywhere. So if you have a molecule that interferes with the stability or the structure of blood vessels, you might expect they will have several unexpected effects,” Pilote said.

Evidence of links

In the case of Alzheimer’s, there is growing evidence of a link between disease and cardiovascular risk factors such as high blood pressure and high cholesterol, Larson said.

He and his research team pulled study samples from a group of participants involved in a major cohort study, which began in 1994 as a joint project between the University of Washington and Group Health.

By July 2006, 110 of those participants had died before age 80 and their brains were autopsied. Of those, 36 percent had taken statins for an average of five years before they died. Compared to the non-statin users, their brains showed significantly fewer of the changes associated with degenerative cognitive illness.

Larson said it’s not clear why there is a difference between the groups; however, previous studies on animals have shown that high levels of cholesterol in the brain may alter brain function.

The new study contradicts two previous large, randomized, placebo-controlled trials, which did not find evidence that statin use protects patients from the onset of dementia.

Larson emphasized that the results are preliminary. A potential shortcoming of the study is that only people who agreed to have their brains autopsied were included in the trial.