December 6, 2005
Medicines that lower cholesterol, including the statin drugs taken by millions of Americans with high cholesterol, may help slow progression of Alzheimer's disease, French researchers report. The study, which appeared in the Journal of Neurology Neurosurgery and Psychiatry, adds to a growing body of evidence that keeping cholesterol levels in check may help keep the mind sharp.
Researchers at University Hospital in Lille, France, monitored the progress of 342 people with Alzheimer's disease who were attending a memory clinic. They were given regular check-ups and memory tests for almost three years. Most were women, with an average age of 73 years.
More than a third, or 129, of the seniors were on drugs to treat high cholesterol levels -- including statins, such as Lipitor or Zocor, with or without other cholesterol-lowering medications. Another 105 had high cholesterol levels but were not being treated for it, while 108 had healthy cholesterol levels.
During the three years of the study, all the people with Alzheimer's disease showed signs of mental deterioration, but the disease progressed significantly more slowly in the patients given cholesterol-lowering drugs.
The findings are consistent with a small study from 2004, which found that statin drugs may slow the progression of Alzheimer's disease. (See the story "Cholesterol Pill May Slow Alzheimer's Progression".) The authors of the study likewise concluded that cholesterol-lowering medications may effectively slow progression of Alzheimer's disease. However, they also called for a trial involving a larger number of people to confirm their findings.
An editorial by Dr. Frank-Erik de Leeuw that accompanied the article also argued that it is still to early to conclude definitively that statins or other cholesterol-lowering drugs should be routinely given to people with Alzheimer's disease. "There is conflicting evidence for a causal relation between cholesterol, its treatment, and the incidence of Alzheimer's disease," said Dr. Leeuw.
It also remains uncertain whether statins or other cholesterol-lowering drugs may help to lower the risk of developing Alzheimer's or other forms of dementia. A study earlier this year, for example, found that among younger people aged 20 to 40, keeping cholesterol in a healthy range and avoiding other risk factors for heart disease may help to keep the brain young as we age. (See the story, "Be Good to Your Heart, and Your Brain May Thank You".) However, a study earlier this year from the University of Washington in Seattle found that statin drugs did not help to ward off Alzheimer's. (See the story, "Cholesterol Lowering Drugs of Uncertain Benefit for Alzheimer's".)
Anyone whose doctor has prescribed a cholesterol-lowering medication should certainly continue taking it. These drugs have proven benefits for heart health, as they help to lower "bad" LDL cholesterol, a known risk factor for heart attacks, and keep blood vessels open and clear. Statin drugs may also reduce inflammation, which has been linked to heart disease as well as Alzheimer's disease.
More studies will need to be done to determine whether, and if so, who might derive brain benefits from the use of cholesterol-lowering drugs. In the meantime, experts advise that everyone follow a heart-healthy diet and get plenty of exercise, lifestyle factors that appear to benefit both heart and mind.
I Masse, R Bordet, D Deplanque, et al: "Lipid lowering agents are associated with a slower cognitive decline in Alzheimer's disease." Journal of Neurology Neurosurgery and Psychiatry. Volume 76: pages 1624-9, 2005.
F-E de Leeuw: Lipid lowering agents to delay cognitive decline in Alzheimer's disease? (editorial). Journal of Neurology Neurosurgery and Psychiatry. Volume 76: 2005