Statins, a group of drugs taken by millions of people to lower cholesterol, may also ward off Alzheimer's disease and other forms of dementia, according to preliminary studies.
During the past decade, numerous studies have hinted that a risk factor for heart disease--high blood levels of lipids such as cholesterol and triglycerides--may also contribute to the development of Alzheimer's disease. If so, statins, a group of lipid-lowering drugs that also protect blood vessels, might help stave off Alzheimer's, reasoned neurologist David Drachman of the University of Massachusetts Medical School in Worcester and pharmaceutical epidemiologist Hershel Jick of Boston University's School of Medicine.
Searching through health records from the United Kingdom, the researchers studied 60,000 people older than 50. They looked at the incidence of Alzheimer's disease and other dementias as well as patients' prescription histories for lipid-lowering drugs. "To my utter astonishment," Jick says, patients on statins had a 70% lower risk of dementia, a result that he and Drachman report in the 11 November issue of The Lancet. The risk was not decreased in people who had normal cholesterol levels or who used drugs other than statins to reduce lipids. "Lowering cholesterol was not the key feature," Drachman says. "Rather, statins have other actions [including their blood-vessel-protecting abilities] that we really believe are important."
The study confirms a report in the October Archives of Neurology from a team led by cellular biologist Benjamin Wolozin of the Loyola University Chicago Medical Center. After digging through records of 40,000 elderly people from three U.S. hospitals, Wolozin found that two kinds of statins reduced the risk of Alzheimer's by 60% to 73%.
Some neuroscientists are skeptical. Despite the large numbers of records, "it's a very small data set," says neuropharmacologist Floyd Bloom of the Scripps Research Institute in La Jolla, California. Drachman's study, for instance, included only 284 new cases of Alzheimer's, and of those, just 13 patients had used statins. "It's hard for me to view that as significant," Bloom says. Still, says neuroscientist Bill Rebeck of the Massachusetts General Hospital in Boston, it's "exciting" that the studies had similar outcomes, and that they both confirmed a previous hypothesis.
A better answer may come from a clinical trial to test one statin, Lipitor, in the treatment of Alzheimer's disease, which has just begun at the Sun Health Research Institute in Sun City, Arizona.