A new international study suggests that people who naturally have lower cholesterol levels may have a much lower risk of developing dementia later in life.
The research looked at health and genetic data from more than one million people and found a strong connection between low cholesterol and a reduced chance of dementia.
The study was led by Dr. Liv Tybjærg Nordestgaard while working at the University of Bristol in the United Kingdom and Copenhagen University Hospital in Denmark.
The results were published in the scientific journal Alzheimer’s & Dementia, which is the official journal of the Alzheimer’s Association. The findings add new evidence that cholesterol levels may play an important role in brain health.
Cholesterol is a fatty substance that is found in the blood. The body needs some cholesterol to build cells and produce hormones. However, when cholesterol levels become too high, it can cause problems for the heart and blood vessels.
High cholesterol can lead to fatty deposits building up in the walls of arteries, a condition known as atherosclerosis. These deposits can narrow blood vessels and make it harder for blood to flow through them.
For many years, doctors have focused on cholesterol mainly because of its role in heart disease and stroke. But scientists are now becoming more interested in how cholesterol might affect the brain. Dementia is a condition that affects memory, thinking, and behavior. It usually develops slowly over many years and becomes more common as people grow older.
Because dementia develops over such a long period of time, it is difficult to study. It can take decades for symptoms to appear, which makes it challenging for researchers to test possible causes and prevention methods. This is why scientists are exploring new ways to understand the disease.
In this study, the researchers used a method called Mendelian randomization. This method uses natural genetic differences between people to study how certain biological factors influence disease risk.
Some people are born with genes that naturally lower their cholesterol levels throughout their lives. These genetic traits affect the same biological pathways targeted by common cholesterol-lowering medicines, such as statins and ezetimibe.
Because these people have had lower cholesterol since birth, their genes provide a natural way for scientists to study the long-term effects of low cholesterol without waiting for decades of clinical trials.
The researchers compared people who had these cholesterol-lowering genetic traits with people who did not. By analyzing such a large group of individuals, the team was able to look for patterns in dementia risk.
The results were striking. The scientists found that even a modest reduction in cholesterol levels could be linked to a large decrease in dementia risk. In some cases, a drop of about one millimole per liter in cholesterol was associated with as much as an 80 percent lower risk of developing dementia.
Dr. Nordestgaard explained that people with these genetic traits appear to be far less likely to develop dementia as they age. This suggests that lower cholesterol levels might help protect the brain. However, she also stressed that the results do not prove that cholesterol-lowering medications will definitely prevent dementia.
More research is needed to understand the connection fully. Scientists still do not know exactly why cholesterol may influence dementia risk. One possible explanation involves the buildup of fatty material in blood vessels.
When cholesterol accumulates in the walls of arteries, it can cause atherosclerosis. This process can occur throughout the body, including in blood vessels that supply the brain.
When arteries become narrowed or blocked, blood flow to brain tissue can be reduced. In some cases, small clots can form and damage brain cells. Over time, these problems may contribute to memory loss and other symptoms associated with dementia.
Dr. Nordestgaard noted that atherosclerosis increases the chance of small blood clots forming in blood vessels. These clots can interfere with normal brain function and may play a role in the development of dementia.
The findings of this study highlight the possibility that managing cholesterol levels may benefit not only heart health but also brain health. If future research confirms these results, treatments that lower cholesterol could potentially become part of strategies to reduce dementia risk.
The researchers believe that the next step would be long-term clinical studies that follow people for many years. These studies might examine whether cholesterol-lowering medications, such as statins, can help prevent dementia if taken over long periods of time.
Such studies could take 10 to 30 years to complete, but they may provide clearer answers about whether lowering cholesterol directly protects the brain.
For now, the study offers encouraging evidence that something as common as cholesterol levels may influence the health of the brain. It also opens the door to new research aimed at understanding how to prevent dementia and support healthy aging.
If you care about dementia, please read studies about low choline intake linked to higher dementia risk, and how eating nuts can affect your cognitive ability.
For more information about brain health, please see recent studies that blueberry supplements may prevent cognitive decline, and results showing higher magnesium intake could help benefit brain health.
Copyright © 2026 Knowridge Science Report. All rights reserved.
