We’ve always been told that high levels of “good” cholesterol are helpful, especially for heart health.
But a surprising new study from Monash University has found that having very high levels of this cholesterol might not be good for your brain.
In fact, it could increase the risk of dementia in older adults.
This study was published in the medical journal The Lancet Regional Health—Western Pacific. It looked at older adults, most over the age of 70, who were generally healthy when the research began. These people were part of a much larger study called ASPREE, which started back in 2010.
The goal of ASPREE (Aspirin in Reducing Events in the Elderly) is to explore different aspects of aging and health in older people. The original study included more than 16,000 older Australians and around 2,400 older Americans who had no serious health issues when they joined.
For this new research, scientists followed the participants for about 6.3 years. They were especially interested in a cholesterol type called HDL-C, often nicknamed “good cholesterol.” Most of the time, HDL-C is praised for helping remove bad fats from the blood and protecting the heart.
But in this study, the researchers focused on people who had extremely high HDL-C levels—above 80 mg/dL (or 2.07 mmol/L). That’s much higher than what most people have.
What they found was unexpected. People with these very high HDL-C levels had a 27% higher risk of developing dementia than those with more typical levels. Even more striking, people aged 75 and older with very high HDL-C had a 42% greater risk of getting dementia.
It’s important to know that such high cholesterol levels are rare and usually not caused by eating certain foods. Instead, they might be linked to unusual conditions in how the body handles cholesterol. The researchers pointed out that these extremely high levels could be signs of a metabolic problem.
The study included a total of 18,668 people, and out of those, 2,709 had very high HDL-C when the study began. The results show that while good cholesterol helps with heart health, having too much of it could possibly harm brain health in older age.
Dr. Monira Hussain, the study’s lead author and a senior research fellow at Monash University, said more research is needed to understand why this happens.
Scientists still don’t fully know how or why very high levels of HDL-C could raise the chance of dementia. But this study offers new clues and raises important questions for doctors and researchers.
The research is ongoing. The ASPREE study has now entered a new phase called ASPREE-XT (Extension), where scientists continue to observe participants’ health as they age. This long-term follow-up may help provide more answers in the future.
This discovery adds to the complex picture of how different parts of our health are connected. It suggests that brain health is not just about avoiding harmful things, but also about keeping even the “good” things, like cholesterol, in balance.
If you’re interested in keeping your brain healthy as you age, you might want to learn more about the Mediterranean diet, which has been shown to protect brain function. You can also look into how blueberries and antioxidants may help prevent mental decline. Some studies have even found that coconut oil could improve brain function in people with Alzheimer’s.
The findings from this study were published in The Lancet Regional Health—Western Pacific.
If you care about Alzheimer’s, please read studies about the likely cause of Alzheimer’s disease , and new non-drug treatment that could help prevent Alzheimer’s.
For more health information, please see recent studies about diet that may help prevent Alzheimer’s, and results showing some dementia cases could be prevented by changing these 12 things.
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