Glucosamine, a widely used over-the-counter joint supplement, was associated with a 25% higher likelihood that mild cognitive impairment would advance to dementia in a new analysis of University of Florida Health records. The retrospective study, published in Nature Metabolism, also found a 25% higher mortality risk among glucosamine users who already had Alzheimer's disease or related dementias, though not in the MCI group.
Using AI to analyze deidentified records from 2012 to 2024, the researchers identified 1,896 patients with ADRD and 2,750 with MCI, with 8% of each group reporting glucosamine use. The association held after adjusting for age, sex, and demographics. The authors stress that observational data cannot prove causation, as supplement users may differ in other ways.
To explore a possible mechanism, the team examined human brain tissue and mouse models. They found evidence that glucosamine, which can cross the blood-brain barrier, may intensify a metabolic process that attaches sugar structures to proteins—activity that appears abnormally elevated in Alzheimer's disease. Senior author Ramon Sun said the findings support a growing focus on altered metabolism in neurodegeneration, but added that clinical trials are needed to determine whether the supplement actually causes harm.