Glucosamine, one of the most commonly used over-the-counter supplements for joint pain, was associated with a greater likelihood that mild cognitive impairment would progress to dementia, according to researchers at the University of Florida. Mild cognitive impairment, or MCI, refers to memory or thinking problems that are measurable and go beyond normal aging, but that do not necessarily disrupt daily life in a major way.
The conclusion draws on a large retrospective analysis of patient health records, backed up by laboratory work in human brain tissue and in mouse models of Alzheimer's disease. Combining population-level records with tissue and animal experiments is a common way to look for a biological explanation behind a statistical pattern, though it stops short of proving that the supplement itself drives the decline.
The researchers frame the results as part of a broader line of evidence that disrupted metabolism matters in neurodegeneration - a shift away from viewing Alzheimer's purely through the lens of protein plaques and tangles. Senior author Ramon Sun, Ph.D., who directs UF's Center for Advanced Spatial Biomolecule Research and serves as associate director for innovation at the university's McKnight Brain Institute, noted that roughly 7 million Americans are living with Alzheimer's and millions more with related conditions such as Lewy body or frontotemporal dementia, and that many of them take an over-the-counter supplement that may be worsening their disease course.
The team is clear that the findings are preliminary and will need testing in a human clinical trial before anything definitive can be said. For now, the practical value lies in flagging a widely consumed product that has largely escaped scrutiny in dementia research.