A large international study has found that lower cholesterol levels may help reduce the risk of developing dementia.
The research, led by scientists at the University of Bristol and Copenhagen University Hospital, looked at data from more than one million people across Denmark, England, and Finland. It was published in the journal Alzheimer’s & Dementia.
The study focused on people who were born with specific genetic variants that naturally lower their cholesterol levels. These genetic differences affect the same proteins that popular cholesterol-lowering drugs, such as statins and ezetimibe, target.
Because these people have naturally lower cholesterol throughout their lives, researchers could study them to understand how cholesterol levels influence dementia risk without the interference of lifestyle habits like diet or exercise.
Using a method called Mendelian Randomization, which uses genetics to simulate the effects of medication, the researchers compared people with these cholesterol-lowering variants to those without them.
They discovered that people with lower cholesterol due to genetics had a significantly lower risk of getting dementia. In some cases, reducing cholesterol by just one millimole per liter was linked to as much as an 80% lower risk of developing dementia.
Dr. Liv Tybjærg Nordestgaard, the study’s lead author, explained that this suggests cholesterol plays a major role in the development of dementia. While the study cannot say for sure whether cholesterol-lowering drugs directly prevent dementia, it does show that people with lifelong low cholesterol tend to have much lower dementia rates.
This finding is important because it suggests that keeping cholesterol low—whether through genetics or medication—might protect the brain later in life. However, Dr. Nordestgaard pointed out that more research is needed. Dementia typically appears late in life, which makes long-term studies difficult.
A future step could be to run randomized clinical trials that follow people for 10 to 30 years to directly measure whether taking cholesterol-lowering drugs reduces the chance of developing dementia.
Scientists still don’t fully understand how high cholesterol leads to dementia, but one theory is that it increases the risk of atherosclerosis. This is a condition where cholesterol builds up in the blood vessels, including those in the brain, making it easier for small blood clots to form. These clots can damage brain tissue and contribute to different types of dementia.
The study drew on genetic and health information from several major research projects, including the UK Biobank, the Copenhagen General Population Study, the Copenhagen City Heart Study, the FinnGen study, and the Global Lipids Genetics Consortium.
While the research doesn’t prove that taking cholesterol-lowering medication will definitely prevent dementia, it does highlight the importance of cholesterol in brain health. The findings could lead to new ways of preventing dementia by focusing on cholesterol as a risk factor.
As scientists continue to explore this connection, the hope is that more people can take early steps to protect their brains—possibly by managing cholesterol levels not just for heart health, but also for long-term brain health.
If you care about Alzheimer’s disease, please read studies about Research shows root cause of Alzheimer’s disease and new treatment and findings of Scientists find the link between eye disease glaucoma and Alzheimer’s disease.
For more about Alzheimer’s disease, please read studies about Scientists find a new way to treat Alzheimer’s disease and findings of Fluctuating cholesterol and triglyceride levels are linked to Alzheimer’s disease.
The study is published in Alzheimer’s & Dementia.
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