A popular joint health supplement has been linked to a 25% higher likelihood of progressing from mild cognitive impairment to dementia, according to new research from the University of Florida.

Researchers found that people with mild cognitive impairment who took glucosamine were more likely to develop dementia than those who did not use the supplement.

The findings raise concerns about glucosamine use among people with memory problems. However, researchers cautioned that the study does not prove the supplement causes Alzheimer’s disease or accelerates cognitive decline.

The study, published in the journal Nature Metabolism, examined patient medical records, human brain tissue and laboratory mice.

Glucosamine is a naturally occurring compound found in cartilage, the tissue that cushions joints. It is widely sold as an over-the-counter supplement, particularly among older adults seeking relief from joint discomfort.

Researchers analyzed University of Florida health records collected between 2012 and 2024. The study included patients diagnosed with mild cognitive impairment or Alzheimer’s disease and related dementias.

About 8% of patients in each group reported taking glucosamine. That included 2,750 people with mild cognitive impairment and 1,896 people with dementia.

After accounting for age, sex and demographic factors, researchers found that glucosamine use was associated with a 25% higher likelihood of progressing from mild cognitive impairment to dementia.

Among patients who already had Alzheimer’s disease or related dementias, glucosamine use was also associated with a 25% higher risk of death.

No similar increase in mortality risk was observed among patients with mild cognitive impairment.

Researchers also investigated a biological process called glycosylation, in which cells attach sugar molecules to proteins.

This process helps proteins function properly, but researchers found that it appeared to be excessively active in brains affected by Alzheimer’s disease.

Excessive sugar attachment may interfere with proteins involved in communication between nerve cells. Glucosamine can cross the blood-brain barrier and provide additional material for producing these sugar structures.

To examine the potential effects, researchers conducted experiments involving healthy mice and mice with Alzheimer’s-like disease.

In healthy mice, glucosamine did not increase sugar attachment or affect memory performance.

However, mice with Alzheimer’s-like disease showed increased sugar attachment and performed worse on a memory test after receiving glucosamine.

When researchers used a chemical treatment to suppress the sugar attachment process, memory performance improved.

Further examination of human brain tissue revealed significantly more sugar attachment in samples from Alzheimer’s patients than in healthy controls.

The results suggest that disrupted metabolism may contribute to Alzheimer’s progression and could become a target for future treatments.

Still, researchers stressed that the human findings remain preliminary.

The analysis relied on medical records, which may not accurately document every supplement a patient takes. The records also did not reliably establish supplement dosage, duration of use or how consistently patients took it.

Other factors, including arthritis, pain, mobility problems and medication use, could have influenced the findings.

The patient-record analysis did not examine whether glucosamine poses similar risks to people with normal cognitive function.

“A brain affected by dementia and a healthy brain are different biological environments, and we shouldn’t assume a supplement behaves the same way in both,” senior study author Ramon Sun, Ph.D., told Fox News Digital.

Researchers are calling for controlled human clinical trials to determine whether glucosamine directly accelerates cognitive decline.

For now, the findings do not establish that patients should stop taking glucosamine.

Sun advised people diagnosed with cognitive impairment or dementia who currently take the supplement to discuss its use with their doctors before making changes.