April 28, 2003
Scientists from the University of Texas Southwestern Medical Center in Dallas have gathered more evidence that what's good for the heart may also be good for the brain. The popular cholesterol-lowering drugs called statins reduced levels of brain cholesterol by more than 20 percent, an effect that could prove beneficial for those suffering from the ravages of Alzheimer's disease, they report. Still, the trial was small, and more research is needed before doctors can recommend these medicines routinely for those suffering from or at risk for Alzheimer's.
The study, in the April 22, 2003 issue of the medical journal Archives of Neurology, looked at 44 people with Alzheimer's disease, none of whom had heart problems. They were assigned to receive 40 mg a day one of three common statin pills or a gram a day of another cholesterol-lowering medicine called niacin. Lab tests showed that taking statin drugs for six weeks reduced levels of brain cholesterol by an average of 21.4 percent, while niacin reduced it by about half as much.
"This class of drugs [statins] may be potentially beneficial in the treatment of Alzheimer's disease," says Dr. Gloria Vega, the study's lead author.
Popular statin medicines, which all work similarly, include lovastatin (Mevacor), pravastatin (Pravachol, and simvastatin (Zocor)--the three tested in this study--as well as fluvastatin (Lescol), and atorvastatin (Lipitor).
Lowering Brain Cholesterol
Scientists are hopeful that lowering cholesterol buildup in the brain may be beneficial against Alzheimer's by stemming the accumulation of a substance called amayloid precursor protein (APP). All of us produce APP, but in people with Alzheimer's disease, the protein gives rise to a toxic substance called beta amyloid that builds up and eventually kills brain cells.
The trial adds to growing body of evidence that taking cholesterol-lowering drugs may benefit those with Alzheimer's disease. Still, most studies have been small--like this one--and findings preliminary.
Dr. Samuel E. Gandy, Chairman of the Scientific Advisory Board at the Fisher Center for Alzheimer's Research Foundation, notes that as with all medicines, further rigorous testing is needed to determine whether taking cholesterol-lowering drugs actually helps people with Alzheimer's to think more clearly, or whether these medicines can treat or prevent the disease in the long run. A larger study from the National Institute on Aging to assess whether statin drugs slow the progression of Alzheimer's is under way and should provide more conclusive answers, but results are not expected for one to two years.
It is therefore still too early for doctors to start prescribing statin medicines to treat Alzheimer's disease or to prevent it. Statins are, however, now taken by millions of people daily to lower unhealthy levels of cholesterol and appear to be safe for most people over the long term. Other research suggests that a heart-healthy diet and exercise may also be beneficial against Alzheimer's.
For more about ongoing research on statins and Alzheimer's disease, see "Can cholesterol-lowering drugs prevent Alzheimer's disease?"
By Toby Bilanow, Medical Writer for www.ALZinfo.org, The Alzheimer's Information Site.
Reviewed by Samuel E. Gandy, M.D., Ph.D., Chairman of the Scientific Advisory Board, Fisher Center for Alzheimer's Research Foundation.