Your Brain on Statins

Wolozin says that more clinical trials are essential but will be prohibitively expensive, especially when it comes to measuring preventative benefits—because the duration of such trials would have to be much longer than is typical. "Because of the cost," he says, "we might never be able to fully test whether statins reduce the incidence of Alzheimer's disease or dementia."
But why would we look to statins to treat cognitive health in the first place? The drugs have several characteristics that make them good candidates. By reducing cholesterol—which is what they were designed to do—statins help maintain a strong blood supply to the brain.

Researchers also believe that less cholesterol means less beta-amyloid, a small protein that accumulates in the brains of Alzheimer's patients. In addition to their effects on cholesterol, statins also inhibit inflammation, another plus for the vasculature of the brain. It's also possible that statins work to inhibit some insulin pathways; high insulin levels in the brain have been associated with Alzheimer's disease. "We know that they have these properties and that they may work differently in different populations," says Haan. "But we don't really know which of the pathways the cognitive benefits come from."

Until that question is answered, she says, it's too soon to say whether people can or should take statins for general cognitive health. In fact, too little cholesterol can be just as damaging to cognition as too much. The brain makes its own cholesterol, and reducing that natural synthesis might actually promote cognitive decline. "We need to answer many questions before we can promote statins for preventative cognitive health," says Wolozin. "We are not there yet."

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