Can Low Cholesterol Keep Your Brain Healthy?

From the WebMD Archives

Most people think of heart disease when they hear the words "high cholesterol," but your brain's health may also be at stake.

The evidence is still limited, but studies show that high levels of cholesterol may be linked to Alzheimer's disease or other kinds of dementia.

The Role of Cholesterol

Researchers don't know exactly what causes Alzheimer's disease. But substances found in the brains of people with Alzheimer's, called amyloid plaques, may be part of it.

Amyloid plaques form in the brain when a protein called beta-amyloid builds up. That's where cholesterol may come in.

In a recent study, Charles DeCarli, MD, director of the University of California, Davis Alzheimer's Disease Research Center, and colleagues looked at levels of amyloid in the brains of 74 older adults.

They found that higher levels of LDL cholesterol and lower levels of HDL cholesterol both were linked to having more amyloid in the brain.

"Unhealthy patterns of cholesterol could be directly causing the higher levels of amyloid known to contribute to Alzheimer's, in the same way that such patterns promote heart disease," says Bruce Reed, MD, a study researcher and a co-director of the UC-Davis Alzheimer's Center.

The study, the first to link cholesterol to amyloid plaques in the brain, doesn't directly say whether or not cholesterol is a risk for dementia, DeCarli says.

"We primarily looked at people who did not have dementia. There are still a lot of questions. But now that we have this amyloid imaging tool, we can actually ask those questions and identify relationships we couldn't see before."

Improving Your Cholesterol Numbers

One potential next step for researchers is to study whether or not changing a person's HDL or LDL cholesterol levels earlier in life can reduce amyloid levels in the brain later in life.

This could potentially make a big difference in reducing the number of people with Alzheimer's, Reed says.

What's clear, DeCarli says, is that if you're at risk for heart disease because your cholesterol levels aren't right, you have one more reason not to ignore the numbers. Your risk of Alzheimer’s might be less after cholesterol treatment.

Changes in your lifestyle can improve your cholesterol numbers. A diet low in saturated fat may help reduce LDL "bad" cholesterol. Regular exercise may be helpful in boosting HDL "good" cholesterol.

WebMD Feature Reviewed by Arefa Cassoobhoy, MD, MPH on April 25, 2014

Sources

SOURCES:

American Heart Association: "Why Cholesterol Matters."

Charles DeCarli, MD, director, University of California, Davis Alzheimer's Disease Research Center.

Bruce Reed, MD, co-director, University of California-Davis Alzheimer's Disease Research Center.

Reed, B. JAMA Neurology, December 2013.

Weijiang, D. Journal of Lipid Research, October 2009.

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