Glucosamine supplements may accelerate dementia progression, study finds

A common supplement taken for knee pain, glucosamine, may inadvertently speed up the progression of dementia, according to a new study from the University of Florida. The research, published in the journal Nature Metabolism, analyzed data from patients diagnosed with mild cognitive impairment or Alzheimer's-related dementia between 2012 and 2024.

The findings indicate that individuals taking glucosamine supplements had a 25% higher likelihood of progressing from mild cognitive impairment to dementia compared to those who did not take the supplement. For patients already diagnosed with Alzheimer's disease, the study revealed a 25% increase in the risk of mortality.

Professor Ramon Sun of the UF McKnight Brain Institute, who led the study, expressed concern that millions of Americans with Alzheimer's and other neurodegenerative diseases might be worsening their conditions through supplement use. The study explored the biological mechanism behind this potential acceleration, focusing on a process called hyper-glycosylation. This phenomenon involves an excessive sugar coating on proteins in the brain, which appears to be more prevalent in Alzheimer's patients.

Experiments with mice genetically engineered to have Alzheimer's showed that administering glucosamine increased hyper-glycosylation and impaired their ability to recognize and remember other mice. Conversely, chemically inhibiting this glycosylation process improved the mice's memory. Analysis of human brain tissue from Alzheimer's patients also revealed higher levels of protein-bound sugar compared to healthy individuals, suggesting a link between this abnormal process and disease severity.

While the researchers caution that this observational study cannot definitively prove that glucosamine directly causes dementia, they strongly recommend that patients diagnosed with mild cognitive impairment or Alzheimer's consult a healthcare professional before taking glucosamine supplements. This advisory aims to ensure patient safety and prevent potential adverse effects on their condition.