January 23, 2008 – According to a recent study, which received media coverage, statins, drugs usually prescribed to lower blood cholesterol levels, are ineffective in preventing Alzheimer’s disease. However, an analysis of the results1 reveals that it may be too early to disqualify statins from the prevention of this degenerative neurological disease.
The American study in question was published on January 16, 2008 in the medical journal Neurology. Researchers at Rush University Medical Center followed a cohort of 929 men and women religious for 12 years, whose average age was 75 at the start of the study. None of the subjects showed signs of Alzheimer’s disease at the time of recruitment and each of them took tests to measure their cognitive functions throughout the study.
In addition, the subjects all agreed to have their brains undergoing an autopsy after death, which is often necessary to confirm a diagnosis of Alzheimer’s disease. Of the cohort as a whole, only 119 subjects were taking prescribed statins to lower their blood cholesterol levels.
After 12 years, Alzheimer’s disease was diagnosed in 20.6% of subjects (191/929). This proportion was 13.4% among subjects who had taken statins (16/119), compared to 21.6% among those who had never taken statins (175/810).
The number of subjects on statins was too low in this cohort to allow a conclusion to a protective effect of these drugs, support the authors of the study. However, for the same reasons, we cannot conclude that they are ineffective in protecting against Alzheimer’s disease.
The role of statins
In addition, more and more researchers agree to recognize that the synthesis of a toxic protein, beta-amyloid, plays a fundamental role in the appearance of the disease. However, the data of the present study indicate that the subjects taking statins had less of this toxic protein than the other subjects.
According to Judes Poirier, director of the McGill Center for Studies in Aging, the “mode of action of statins seems promising.” These drugs would make cholesterol more easily accessible to nerve cells, which need it to maintain the health of their membranes and promote the development of connections between nerve cells, he explains. However, he notes, first-generation statin-type drugs were much less effective at protecting against Alzheimer’s disease compared to those used today.
The brain needs cholesterol to rebuild faulty cellular connections between neurons, adds Judes Poirier. He found that in people with Alzheimer’s disease, brain cells in the brain have a problem transporting or recycling cholesterol. Statins may help compensate for this abnormality by making it easier for neurons to access cholesterol, he believes.
Pierre Lefrançois – PasseportSanté.net
According to Reuters Health.
1. Arvanitakis Z, Schneider JA, et al. Statins, incident Alzheimer disease, change in cognitive function, and neuropathology. Neurology. 2008 Jan 16 [Publication électronique anticipée].
