Study Links Glucosamine Supplement to Faster Dementia Progression in Patients with Mild Cognitive Impairment
A study published in Nature Metabolism found that people with mild cognitive impairment who took glucosamine were 25% more likely to progress to Alzheimer's disease, and those already diagnosed with Alzheimer's faced a 25% higher mortality risk. The University of Florida research combined retrospective analysis of over 65,000 patient records with mouse model experiments and advanced spatial imaging of human brain tissue, identifying excessive protein sugar-coating — hyperglycosylation — as a likely biological mechanism. The findings raise urgent questions about the safety of one of America's most widely used over-the-counter supplements for the tens of millions of older adults who take it for joint pain.
Researchers at the University of Florida, publishing in Nature Metabolism on June 9, found that glucosamine — a supplement taken by more than 40 million Americans annually for joint pain — was associated with a 25% greater likelihood of progression from mild cognitive impairment (MCI) to Alzheimer's disease, and a 25% increase in mortality among patients already diagnosed with Alzheimer's disease and related dementias. The retrospective analysis drew on anonymized UF Health electronic records from 2012 to 2024, covering approximately 24,000 dementia patients and 41,000 MCI patients, of whom roughly 8% in each group reported glucosamine use. Spatial metabolomics and glycomics imaging of human brain tissue revealed dramatically elevated N-glycan abundance in Alzheimer's brains compared to healthy controls, with glycan levels increasing progressively across Braak stages — a measure of disease severity. Stable isotope tracing in 5xFAD Alzheimer's mouse models confirmed that this hyperglycosylation is driven by increased glycan biosynthesis rather than impaired degradation, and that oral glucosamine supplementation worsened memory deficits in these mice while genetic or pharmacological inhibition of key glycosylation enzymes improved cognitive performance. The researchers note that earlier studies linked glucosamine to lower dementia risk in cognitively healthy adults, and they suggest the supplement may be safe or even protective for healthy brains but harmful when the brain's sugar metabolism is already dysregulated. Because the human data are observational, causality cannot be established, and the team plans follow-up studies on patients who discontinued glucosamine and is screening compounds that inhibit the N-glycan pathway as potential therapeutic targets.
What's missing
The study does not address whether the association holds across different glucosamine formulations (e.g., glucosamine sulfate vs. glucosamine hydrochloride), dosages, or duration of use. The study's single-institution health record source (UF Health) may limit generalizability to broader or more diverse populations.
How coverage differed
All outlets covered the story with broadly similar framing; however, Newsweek added commentary from an independent neuropsychologist and included practical lifestyle advice for readers, giving its coverage a more consumer-health orientation, while the Nature Metabolism source and Science Daily emphasized the mechanistic and molecular findings in greater technical depth.
What different sources said
- The IndependentLeft
Popular joint supplement Glucosamine linked to faster Alzheimer’s progression, new study finds
- Medical XpressCenter
A popular joint pain supplement may accelerate dementia
- NewsweekCenter
Popular Supplement Linked to Faster Alzheimer’s Progression
- The ConversationCenter
Glucosamine supplements may speed memory loss from Alzheimer’s, new research shows
- Science DailyCenter
Popular joint supplement glucosamine linked to faster Alzheimer’s progression
- Nature NewsCenter
Hyperglycosylation is a metabolic driver of Alzheimer’s disease
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