Fact checked by Nick Blackmer
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- New research links glucosamine use to faster cognitive decline in people with Alzheimer’s disease and those with mild cognitive impairment.
- Glucosamine is a popular supplement commonly used to help relieve joint pain.
- The study found an association—not proof that glucosamine causes speedier cognitive decline.
Glucosamine, a popular joint pain supplement, may have unintended consequences for people with cognitive decline. A new study found that people with mild cognitive impairment who took glucosamine were more likely to progress to full Alzheimer’s disease, and that people already diagnosed with the condition faced a higher risk of death within five years.
Glucosamine Linked With Accelerated Cognitive Decline
Millions of people in the U.S. take glucosamine, an amino sugar naturally found in cartilage. Marketed to help relieve osteoarthritis and joint pain, the supplement is often used by older adults—the same group most likely to be diagnosed with Alzheimer’s. Researchers wanted to know whether there might be a connection between the supplement and cognitive decline risk.
For the study, published June 9 in the journal Nature Metabolism, the team analyzed University of Florida Health system records of more than 24,000 patients with dementia, including Alzheimer's, and almost 42,000 patients with mild cognitive impairment between 2012 and 2024. About 8% of patients reported taking glucosamine.
After controlling for age, sex, and other demographics, researchers found that glucosamine use was associated with a 25% higher likelihood of progressing from mild cognitive impairment to Alzheimer’s. Typically, there’s only a 5% risk of progression, according to the researchers.
The supplement was also linked with a 25% higher risk of death within five years among patients with Alzheimer’s, though those with mild cognitive impairment didn't see a mortality risk increase.
Why Glucosamine May Play a Role in Cognitive Decline
Researchers believe glucosamine’s effects may be linked to a process called glycosylation, in which sugar molecules attach to proteins and help regulate how cells function.
That belief stems from the team’s previous research, which found that brain tissue from people with Alzheimer’s disease showed signs of increased glycosylation—a finding that “could open up many new therapy possibilities," said Ramon Sun, PhD, a study author and director of the University of Florida Center for Advanced Spatial Biomolecule Research.
Before discovering the link between glucosamine use and accelerated dementia in humans, the researchers also found that glycosamine, which can cross the blood-brain barrier, worsened social memory in mice that already had Alzheimer’s-like symptoms.
Taken together, the researchers’ findings suggest that people with cognitive decline may be more vulnerable to glucosamine’s effects, potentially because the supplement could speed up biological changes already underway, Sun said.
Should You Avoid Glucosamine?
Not necessarily. While the findings “appear robust,” said neurologist Jason Hinman, MD, PhD, director of UCLA’s Easton Center for Alzheimer's Research and Care, who wasn’t involved in the new research, the study comes with important caveats.
For one, the findings suggest a potential link between glucosamine use and accelerated cognitive decline only in people who already have symptoms—not in healthy people. The study also can’t prove that glucosamine causes speedier cognitive decline, and Hinman noted that it didn’t distinguish among different forms of glucosamine supplementation.
To better understand the relationship between glucosamine supplements and Alzheimer’s, large-scale double-blind clinical trials are still needed, Sun said.
Given the study's findings, Hinman said people who take glucosamine as a general wellness supplement—and not for a specific medical reason—may want to reconsider using it. But he doesn’t think there’s enough evidence to recommend that people stop taking it to manage osteoarthritis.
Still, Sun noted that the evidence is inconclusive as to whether glucosamine can even improve joint pain, so taking it may not be worth it regardless. If you take glucosamine, “ask yourself what benefits you’re gaining and if it’s changing your quality of life?,” Sun said. “I would say if there’s no benefit, what’s the point of spending money on it?”
