A common pill used for joint pain might make Alzheimer’s disease get worse faster, according to a new study from the University of Florida.
The researchers looked at people with mild memory problems. Those who said they took glucosamine were more likely to develop full‑blown dementia than those who did not take the supplement.
The results were published on June 9 in Nature Metabolism. The team combined a huge set of health records with detailed brain scans and experiments in mice.
These findings do not prove that glucosamine causes dementia, but they add to growing proof that metabolism – how the body processes food and chemicals – matters a lot for brain health.
Glucosamine Use and Dementia Risk
Because many seniors use glucosamine to keep their joints healthy, the scientists wanted to see if it could also affect Alzheimer’s‑related dementia (ADRD).
Using AI tools, they examined de‑identified UF Health records from 2012‑2024. They focused on patients diagnosed with either ADRD or mild cognitive impairment (MCI).
About 8 % of each group reported taking glucosamine – 1,896 people with ADRD and 2,750 with MCI.
After adjusting for age, sex and other factors, the analysis showed that people with MCI who took glucosamine had a 25 % higher chance of later developing dementia.
The supplement was also linked to a 25 % higher death risk for those already diagnosed with ADRD, but not for the MCI group, suggesting the effect may change as the disease advances.
A Metabolic Pathway That Might Matter
The study highlighted a specific protein‑and‑sugar tagging process that appears too active in Alzheimer’s brains. This pathway could become a new target for future medicines.
“Our results suggest that altered metabolism is a big driver of Alzheimer’s progression,” said lead researcher Dr. Sun. “Fixing this metabolic defect could complement treatments that focus on plaques and tangles.”
These insights were made possible by advanced spatial‑analysis technology that can map thousands of tiny molecules in brain tissue.
How Glucosamine Gets Inside the Brain
Glucosamine is a naturally occurring sugar‑related molecule that can cross the blood‑brain barrier. Once inside, it can join biochemical pathways that attach sugar tags to proteins.
Commercial glucosamine is usually made from shellfish shells or corn. Its impact seems to depend heavily on the surrounding biological environment.
Mouse Experiments and Human Tissue Findings
In genetically engineered mice, glucosamine increased sugar‑tag attachment to proteins and worsened social‑memory abilities. Reducing this tagging chemically improved memory.
Human brain samples from the UF Neuromedicine Brain and Tissue Bank showed far higher levels of sugar‑tagged proteins in Alzheimer’s tissue compared with healthy brains.
“Proteins need the right amount of sugar tags to fold correctly and work,” explained Dr. Gentry. “In Alzheimer’s, the brain adds too many, which seems to fuel the disease rather than protect it.”