Cholesterol Levels Linked to Brain Changes of Alzheimer’s Disease
Study: High Cholesterol Predicts Brain-Clogging Protein Deposits on Autopsy
Important Questions Remain
Experts who reviewed the study for WebMD say its findings are valuable, since few studies have been able to connect blood cholesterol levels to physical changes that happen years later in the brain.
“There’s actually fairly little data on the relationship between cholesterol and Alzheimer’s disease pathology in humans,”says Zoe Arvanitakis, MD, an associate professor in the department of neurological sciences at Rush University Medical Center in Chicago.
“And really there’s little known about the relationship of cholesterol in earlier life to the development of Alzheimer’s disease in later life, and this study tried to get at those two points,” Arvanitakis says.
But Arvanitakis and other experts say the study has important weaknesses that limit what it can say.
“There’s a lot of missing pieces in the chain of evidence in this study,” says Adam Rosenblatt, MD, director of neuropsychiatry at the Johns Hopkins School of Medicine in Baltimore.
Rosenblatt says that although scientists have long suspected that cholesterol plays a role in Alzheimer’s disease, it is still not clear what that may be.
For example, “Studies that have tried to treat or prevent Alzheimer’s disease by lowering cholesterol” using statin medications “have not produced convincing evidence,” he says.
There’s not even enough evidence to show that plaques in the brain cause Alzheimer’s symptoms.
It could be that the disease, he says, is somehow causing both higher cholesterol levels and plaques in the brain, rather than the other way around.
“You really couldn’t conclude from this study that cholesterol causes Alzheimer’s or even makes it more likely, or that lowering your cholesterol would prevent it,” Rosenblatt says.