Can Lowering Your Cholesterol Reduce the Risk of Alzheimer's?

Fact checked by Nick Blackmer

Key Takeways

• A recent study shows that higher and fluctuating lipid levels coincide with higher occurrence of Alzheimer’s disease.

• The study didn’t account for people predisposed to Alzheimer’s or other risk factors.

• Higher cholesterol is a risk factor for many conditions, and heart health and brain health may be linked.

A new study may have some insight into a previously unknown risk factor for Alzheimer’s disease: fluctuating cholesterol levels.

The study, published in Neurology, examined the electronic health records of 11,571 individuals in Olmsted County, Minnesota, from 2006 to 2018. None of the participants had been diagnosed with Alzheimer’s disease at the beginning of the study.

The final analysis showed that those in the group with the most cholesterol fluctuation over 13 years had a 19% higher occurrence of Alzheimer’s. While cholesterol levels alone likely can’t make or break Alzheimer’s risk, experts say its impact on blood flow inflammation are important reasons to get it under control for better brain health.

Related: What Is Cholesterol?

A Single Inch of a Complex Picture

Researchers didn’t just look at cholesterol for the study. They analyzed four lipid measurements: total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C).

Fluctuation in levels of triglycerides, a type of fat, were also linked to a higher risk of Alzheimer’s. Study participants with the most triglyceride fluctuation had a 23% higher risk of Alzheimer’s.

While the study illuminated these previously undiscovered risk factors, experts say that stabilizing cholesterol and triglycerides isn’t a silver bullet for the disease. Christopher Weber, PhD, and director of global science initiatives for the Alzheimer’s Association, told Verywell that heart health and brain health are closely related, but further research is needed to understand the relationship between cholesterol levels, variability, and Alzheimer’s disease progression.

Related: 4 Important Things to Know About Accessing Newly-Approved Alzheimer’s Drug Leqembi

“Cholesterol fluctuations can negatively impact the brain’s vascular health and contribute to an increased risk of developing cognitive decline and dementia, including Alzheimer’s disease,” Weber says.

Weber says that the study also discusses endothelial dysfunction, a non-obstructive form of heart disease, which is an early marker of atherosclerosis and could contribute to the connection between cholesterol fluctuations and Alzheimer’s.

“This could negatively affect cerebral blood flow and increase the risk of cognitive impairment and Alzheimer’s in later life,” Weber said.

While the study does provide some insight on how cholesterol may affect blood flow and cognitive decline, it was very limited in scope and population, giving a very limited view, according to R.J. Tesi, MD, CEO and chief medical officer of immuno-oncology company INmune Bio.

Tesi said that not only were lipid levels more variable in the high-risk groups, but so was stroke, cardiovascular disease, diabetes, obesity, cancer, and death. Isolating cholesterol as a singular risk factor is difficult to do. The participants were also not genotyped to determine if there was a predetermined risk of developing Alzheimer’s disease.

Related: Alzheimer's Disease Causes and Risk Factors

Risks of High Cholestorol

Tesi said that while the study may be inconclusive, cholesterol levels can be an indicator of inflammation.

“Cholesterol is known to cause inflammation in the body, which can affect both the heart and the brain. One of the most important causes of Alzheimer’s is neuroinflammation,” he said. “Neuroinflammation comes from four sources: peripheral inflammation, central inflammation, genetic, and environmental causes. If you can control the ‘drivers‘ of neuroinflammation, you can have an impact on the risk of developing Alzheimer’s disease.”

Weber added that certain modifiable risk factors can reduce the risk of cognitive decline and protect cognitive health.

“The takeaway here is that managing lipid variability is important to overall health, including cognitive health, and may require additional strategies beyond just a prescription of lipid-lowering therapies,” Weber says. “Research is still evolving, but evidence is strong that people can reduce their risk of cognitive decline by making key lifestyle changes, including participating in regular physical activity, staying socially engaged, and maintaining good heart health.”

Related: How to Reduce LDL Cholesterol

How to Lower Cholesterol

Lowering cholesterol is often a multi-pronged undertaking. Several prescription drugs are available to help control cholesterol levels, but Tesi and Weber agree that speaking with your doctor is the best first step.

Related: What Are the Benefits and Risks of High Cholesterol Medication?

“Eating a healthy, well-balanced diet, reducing stress and being more active are all proven ways to lower your cholesterol and live a healthier life in general,” Tesi said. “Also, if you smoke, stop as soon as possible.”

Tesi noted that there is no age benchmark for when you should start paying attention to your heart health and cholesterol levels.

“Maintain normal levels throughout life, and if something like cholesterol, blood pressure or A1C does need to be lowered, managing this metric through lifestyle changes and medication should happen as soon as possible,” he said.

What This Means For You

High cholesterol levels and triglycerides can have a host of health ramifications, so a regular lipid screening is a great idea. Once you know your baseline, create a plan for getting heart healthy and maintaining a healthy weight. Maintaining heart health can help stave off many different conditions, both cognitive and otherwise.