A new large-scale international study led by the University of Bristol has revealed that lower cholesterol levels may significantly reduce the risk of developing dementia. The findings, published in the journal Alzheimer’s & Dementia, are based on data from more than one million people across Denmark, England, and Finland.
Genetic Clues Reveal Cholesterol’s Role in Brain Health
As reported by medicalxpress, the research was led by Dr. Liv Tybjærg Nordestgaard, formerly of the University of Bristol and now at the Department of Clinical Biochemistry, Copenhagen University Hospital—Bispebjerg and Frederiksberg. The team discovered that individuals carrying certain genetic variants that naturally lower cholesterol levels also have a lower likelihood of developing dementia.
These genetic variants affect the same proteins targeted by cholesterol-lowering medications such as statins and ezetimibe. By studying these natural genetic differences, the researchers were able to simulate the long-term effects of these drugs without the influence of lifestyle factors like diet, weight, or exercise.
Using Genetics to Mimic Drug Effects
To examine the link between cholesterol and dementia, the researchers applied a method called Mendelian Randomization—a genetic analysis approach that mimics the impact of specific drug targets. This method allowed them to measure how lowering cholesterol influences dementia risk while minimizing confounding variables.
When comparing individuals with cholesterol-lowering genetic variants to those without them, the team found a striking result: reducing blood cholesterol by just one millimole per liter corresponded to an up to 80% decrease in the risk of developing dementia for certain gene targets.
“Significantly Lower Risk,” Says Lead Author
“Our study indicates that people with these genetic variants that lower cholesterol seem to have a significantly lower risk of developing dementia,” said Dr. Nordestgaard. “This suggests that cholesterol plays a meaningful role in the disease process.”
However, she emphasized that the findings reflect genetic predispositions, not direct effects of medication. “While our results suggest a benefit, we cannot conclusively say that cholesterol-lowering drugs themselves reduce dementia risk,” she cautioned.
Possible Explanation: Cholesterol and Atherosclerosis
Although the exact mechanism remains unclear, high cholesterol is believed to increase dementia risk through atherosclerosis, or the buildup of cholesterol in blood vessels.
“Atherosclerosis can occur in both the body and the brain,” explained Dr. Nordestgaard. “It raises the risk of small blood clots, which can impair brain function and contribute to dementia.”
Next Steps: Long-Term Clinical Trials Needed
Given that dementia typically develops late in life, Dr. Nordestgaard highlighted the need for long-term clinical studies. “It would be a valuable next step to conduct randomized clinical trials spanning 10 to 30 years to observe whether cholesterol-lowering medications directly reduce dementia risk,” she suggested.
A Collaboration of Global Research Data
The study drew from several major data sources, including the UK Biobank, Copenhagen General Population Study, Copenhagen City Heart Study, FinnGen study, and the Global Lipids Genetics Consortium.
A Promising Path for Dementia Prevention
This groundbreaking research strengthens the evidence linking heart health and brain health. By understanding how cholesterol influences cognitive decline, scientists may be one step closer to preventing dementia—one of the world’s most pressing health challenges.