We looked at all the credible, peer-reviewed studies out there, talked to experts, and got to the bottom of the question about whether or not statins cause dementia.
Roughly a quarter of all Americans over the age of 40 in the U.S. take statin drugs — which lower levels of cholesterol — in order to prevent cardiovascular disease. But they might be receiving an unexpected benefit.
Statins reduce the levels of so-called “bad” cholesterol in the body. In people with vascular health issues, this helps to prevent cholesterol build-up in blood vessels and arteries, which in turn benefits blood pressure, and helps prevent a stroke or a heart attack.
But, these benefits are sometimes overshadowed by misinformation on the internet, according to Heather Ferris, a clinical endocrinologist and scientist at the University of Virginia who studies cholesterol metabolism and its relationship to Alzheimer’s.
A minority of researchers believe that statins which can cross into the brain — known also called “lipid-soluble” statins — may cause cognitive impairment or dementia (though these claims are seldom backed by evidence). This camp includes David Diamond, a professor of psychology at the University of South Florida. “You’ll wonder, because now statins are so widely prescribed to a high percentage of older people and we have an epidemic of Alzheimer’s disease,” Diamond told Being Patient.
Ferris said that not only is there is no evidence to support the association between statins and increased instance of dementia — these claims and comments sometimes prompt or scare people to disregard their doctors’ advice and ditch their statins.“These drugs really do save lives,” Ferris said. “I can’t tell you how much time we spend as physicians trying to get cardiac patients back on their statins because of the clickbait they read.”
Can statins cause dementia or memory impairment?
Concerns about statins out there because, frankly, the relationship between cholesterol and Alzheimer’s disease is downright strange: Research so far shows that high levels of cholesterol in the blood as well as abnormalities in cholesterol processing in the brain have links to Alzheimer’s. Meanwhile, some statins may be able to cross into the brain and disrupt its cholesterol metabolism.
Further complicating the discussion, this drug class is known to have occasional cognitive side effects: memory loss; confusion. However, research shows these effects don’t last: There is currently no established evidence that statins have any bearing on long-term cognitive function or dementia risk.
Some vocal opponents of statins have made the unfounded leap that because some statins cross into the brain, and because they may lead to cognitive issues in a small portion of the population, they can lead to dementia.
“These symptoms are immediate and reverse with stopping the medication,” Ferris told Being Patient.
The bottom line: There’s no evidence that
statins cause Alzheimer’s or dementia. In fact,
there’s research into whether they might even
help prevent it.
Ferris pointed to clinical trials of mild to -moderate Alzheimer’s: Taking statins daily had no impact on cognition for these patients. Meanwhile, one of the largest statins studies to date looked at a number of double-blind, controlled trials lasting longer than a year and found that statins didn’t have more cognitive side effects than the placebo group.
According to Ferris, patients are concerned about the yet-to-be-determined possibility that statins may be able to make their way into the brain (which may still not have any negative consequences, Ferris notes), they can switch to a less lipid-soluble statin — one with less ability to cross the blood-brain barrier — “but the frequency that this makes a difference is exceedingly rare,” Ferris said.
Could statins actually lower the risk of Alzheimer’s or dementia instead?
The bottom line: There’s no evidence that statins cause Alzheimer’s or dementia. In fact, there’s research into whether they might even help prevent it. Not only are these “wonder drugs of cardiology” beneficial for cardiovascular health and cholesterol, and researchers are currently exploring whether they could also boost brain health. But there are a lot of variables to control for, Ferris pointed out.
“Epidemiological studies showed that people taking statins were less likely to develop Alzheimer’s disease,” she said. “But people on statins are accessing the health care system, so there are a lot of other potential factors that could be playing a role in this difference.”
While there are some studies that find statins may reduce the risk of developing Alzheimer’s by as much as 20 percent, there are many others that find no difference. A lot of these studies are observational and don’t account for any other confounding variables like race or socioeconomic status. Ferris also said that randomized-controlled trials where people either receive a placebo or a statin, have not convincingly shown a significant benefit for statins in preventing Alzheimer’s disease.
Nonetheless, studies are underway to determine whether certain statins have this extra benefit. In the meantime, Ferris and colleagues say, patients should skip the clickbait and stick with their prescribed statin regimen.