For years, doctors have known that being obese increases the risk of many serious health problems, but the exact connection between obesity and Alzheimer’s disease has remained unclear.
Now, a new study from Houston Methodist has shed light on how body fat may actually help trigger one of the key features of Alzheimer’s.
The researchers discovered that small messengers in the body, called extracellular vesicles, could be the missing link. These tiny, bubble-like particles are released by fat tissue and carry information from one cell to another.
In people with obesity, the vesicles contain a different mix of fatty molecules compared to those in lean individuals. These changes seem to speed up the formation of amyloid-β plaques, the sticky clumps that build up in the brains of people with Alzheimer’s.
The study, published in the journal Alzheimer’s & Dementia, was led by Dr. Stephen Wong and his team at Houston Methodist. Dr. Wong pointed out that obesity is now seen as the number one preventable risk factor for dementia in the U.S., which affects more than 7 million people.
Using samples from people’s body fat and lab mice, the researchers carefully studied how these extracellular vesicles behaved.
They found that vesicles from obese individuals carried different lipids—special fat molecules—that made amyloid-β clump together faster. These vesicles are small enough to cross the blood-brain barrier, meaning they can deliver harmful messages directly to the brain.
This is important because amyloid-β plaques are known to be one of the first signs of Alzheimer’s disease. If fat tissue is sending out messages that speed up plaque formation, this might help explain why obesity increases Alzheimer’s risk.
Dr. Wong and his team say their findings open the door to new treatments. If scientists can find a way to block or change these vesicles, it might be possible to slow or prevent Alzheimer’s in people who are overweight or obese. Future studies will look at how drugs might stop these harmful messages from reaching the brain.
The research team included experts from Houston Methodist, The Ohio State University’s Wexner Medical Center, and the University of Texas Health Science Center at San Antonio. Their collaboration combined knowledge in biology, brain science, and medical imaging to make this discovery possible.
As obesity continues to affect around 40% of the U.S. population, understanding how it impacts brain health is more important than ever. This study adds to the growing evidence that what happens in our body fat can have a major effect on our brain—and it offers hope for new ways to protect memory and thinking as we age.
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.
The study is published in Alzheimer’s & Dementia.
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