The popular joint supplement glucosamine has been linked to a 25% faster progression from mild cognitive impairment to Alzheimer’s disease.
A major new study published in Nature Metabolism has revealed a concerning association between glucosamine, a widely used over-the-counter in, and accelerated cognitive decline. Researchers at the University of Florida analyzed 12 years of electronic health records and found that patients with mild cognitive impairment (MCI) who regularly took glucosamine were 25% more likely to progress to full Alzheimer’s disease compared to non-users.
The risks extended further: among individuals already diagnosed with dementia, glucosamine use was associated with a 25% higher mortality risk. Scientists believe the supplement may worsen the condition because glucosamine readily crosses the blood-brain barrier and fuels an overactive “sugar-tagging” (hyperglycosylation) pathway in vulnerable brains, aggravating metabolic dysfunction.
Importantly, this risk appears to be specific to people whose brains are already undergoing neurodegeneration. In healthy individuals, some earlier research has actually suggested potential protective effects. However, with tens of millions of people — many of them older adults — taking glucosamine for joint health, these findings highlight the need for caution and further clinical trials.
[Hawkinson, T. R., Gentry, M. S., & Sun, R. et al. (2026). Hyperglycosylation is a metabolic driver of Alzheimer’s disease. Nature Metabolism. DOI: 10.1038/s42255-026-01538-4]
