Taking glucosamine, a popular over-the-counter joint supplement, may accelerate cognitive decline in people with early signs of Alzheimer's disease, according to a new study from the University of Florida.
The Research
Researchers led by Dr. Ramon Sun, director of the Center for Advanced Spatial Biomolecule Research at UF's McKnight Brain Institute, analyzed 12 years of deidentified electronic health records from UF Health (2012–2024) using artificial intelligence. They found that about 8% of patients with dementia or mild cognitive impairment (MCI) were taking glucosamine supplements. After controlling for age, sex, and other factors, the team discovered that glucosamine use was associated with a 25% higher likelihood of transitioning from MCI to full-blown Alzheimer's disease. Among patients already diagnosed with Alzheimer's, glucosamine was linked to a 25% increase in mortality risk.
The study, published in Nature Metabolism, also included animal and post-mortem human brain analyses. Using advanced spatial biomolecule technology, Dr. Sun's team found that glucosamine crosses the blood-brain barrier and hyper-activates a protein "sugar-tagging" pathway. In healthy brains, this pathway helps fold proteins correctly, but in Alzheimer's-affected brains it becomes overactive, adding too many sugar structures that gum up cellular machinery. Mouse experiments confirmed that glucosamine directly accelerated this sugar-tagging process and impaired social recognition memory—and that chemically blocking the tagging reversed the cognitive deficits. Post-mortem brain tissue from Alzheimer's patients showed elevated sugar-tagging footprints compared to healthy controls.
Why It Matters
If you or a loved one has mild cognitive impairment or Alzheimer's disease, these findings suggest that glucosamine supplements could worsen the condition. The study does not prove causation—it's an association—but the converging evidence from records, animal models, and human brain tissue is compelling. For the millions of seniors who take glucosamine for joint pain, this is a wake-up call about potential unintended effects on brain health. The research also highlights metabolic dysregulation as a key driver of neurodegeneration, opening a new therapeutic target beyond amyloid plaques and tau tangles.
What You Can Do
If you have mild cognitive impairment or a family history of Alzheimer's, consult your doctor before taking glucosamine. There are other options for joint health, such as physical therapy or anti-inflammatory diets. Stay tuned for clinical trials that will test whether stopping glucosamine slows cognitive decline. In the meantime, tracking your own cognitive function with tools like the iqgenio test can help you establish a baseline and monitor changes over time.
Source: Neuroscience News
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