November 12, 2004
A popular cholesterol-lowering drug slowed mental decline and helped lift symptoms of depression in people with Alzheimer's disease, a small study has found. Although the results are preliminary and require further testing, the findings add to a growing body of evidence that medications and other measures that boost heart and blood vessel health may aid persons with Alzheimer's or those at risk of developing the illness.
The drug, Lipitor, goes by the generic name atorvastatin. It is one of several medications commonly prescribed to lower high cholesterol and belongs to a class of drugs known as statins. Scientists are hopeful that the drugs may help to lower cholesterol buildup in the brain and stem the accumulation of a toxic substance called beta-amyloid that accumulates in the brains of those with Alzheimer's, damaging and eventually killing healthy nerve cells essential for thinking and memory.
The study, called the Alzheimer's Disease Cholesterol-Lowering Treatment Trial, or ADCLT, evaluated 46 men and women with mild-to-moderate Alzheimer's disease. All the patients were already taking one of the medications currently approved to treat Alzheimer's, such as Aricept, Exelon, or Reminyl. Half were also given Lipitor, while the others received a look-alike placebo pill.
After a year, those who were taking an Alzheimer's drug along with Lipitor scored higher on tests to measure memory and thinking skills. They also exhibited fewer symptoms of depression, a common affliction in those who suffer from Alzheimer's. Fifty-three percent of those taking the Lipitor improved or stabilized, compared to only 28 percent of those taking a placebo.
"These findings are important because the data show that statin treatment may be beneficial when taken with the only currently approved therapy for Alzheimer's disease," says Dr. D. Larry Sparks, Ph.D., a study leader and head of the Roberts Laboratory for Neurodegenerative Disease Research at the Sun Health Research Institute in Arizona. "This may prove that two drugs work better than one alone. There are larger, multi-center trials in progress to confirm these findings."
Related statin drugs, such as lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), and fluvastatin (Lescol), could have potential benefits for brain health as well. These other medications must also be tested, however, because different statins were shown several years ago to have different effects on brain function in animals, even though all the drugs lowered cholesterol.
However, a small study last year from the University of Texas found that several of these drugs reduced buildup of brain cholesterol, suggesting that they might be beneficial in Alzheimer's treatment.
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. 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 regular exercise may also be beneficial against Alzheimer's.
American Heart Association Annual Meeting, New Orleans, LA, November 2004, conference presentation.