A major health-record study has tied a well-known joint supplement to quicker Alzheimer’s disease progression, sparking concern about a product used by millions of older adults.
A team at the University of Florida discovered that taking glucosamine was linked to a 25% increased chance that mild cognitive impairment would turn into dementia. Their work drew on a review of deidentified patient records, backed up by tests on human brain tissue and mice engineered to model Alzheimer’s disease. The report appeared in Nature Metabolism.
What Glucosamine Is
Sold without a prescription, glucosamine is a sugar-related molecule found naturally within the body. It can cross the blood-brain barrier, which acts as a tight control point that limits what substances enter brain tissue from the bloodstream. People over a certain age use it to treat joint discomfort and support joint health.
Glucosamine sold commercially can come from shellfish shells or corn. After entering the brain, it works its way into biochemical pathways where it builds complex sugar structures and attaches them to proteins.
The Health Record Data
Using artificial intelligence, the researchers analyzed UF Health records gathered between 2012 and 2024. Their study centered on patients who were given a diagnosis of Alzheimer’s disease and related dementias, also referred to as ADRD, or mild cognitive impairment, also known as MCI.
Across both groups, 8% of patients said they used glucosamine, which covered 1,896 people with ADRD and 2,750 people with MCI.
When age, sex and demographic factors were accounted for, the study’s findings showed that taking glucosamine was linked to a 25% greater chance that mild cognitive impairment would move forward into dementia.
In individuals who were already living with ADRD, taking glucosamine was tied to a 25% greater chance of dying. The study authors did not find that link in people with MCI, which suggests that glucosamine might exert a more pronounced influence once dementia has taken hold.
The Mortality Result
What stands out is the mortality result for ADRD patients. The finding shows that people with Alzheimer’s disease who took glucosamine were more likely to die over a set period of time.
The findings from the health records do not prove that glucosamine itself leads to faster progression of dementia. Such studies can uncover links, but there could be other differences between those who take the supplement and those who do not that account for the observed results.
A Biological Explanation
A biological mechanism has been found by the researchers which may explain the connection. The work points to a metabolic pathway where sugar structures become attached to proteins. This is a normal and important part of cell biology, yet the researchers discovered signs that it becomes overly active in Alzheimer’s disease.
Sun made the point that irregular activity within this pathway might one day serve as a target for new treatments, adding: “Our results suggest that altered metabolism is a significant contributor to Alzheimer’s progression and, in addition, addressing the metabolic defect could be an important complement to approaches focused on Alzheimer’s plaques and tangles,”.
The Clinical Question
The findings raise a question that now deserves much more attention. “The electronic health record data are very provocative,” said Matt Gentry, Ph.D., chair of UF’s Department of Biochemistry and Molecular Biology and a study co-author. “While it’s an association and not proof of causality, it does raise an important clinical question that now deserves much more attention.”
Key Facts Box
- Study: Published in Nature Metabolism
- Records analyzed: UF Health records, 2012–2024
- MCI patients using glucosamine: 2,750
- ADRD patients using glucosamine: 1,896
- Association: 25% higher likelihood of MCI progressing to dementia
- Mortality association: 25% higher in ADRD patients, not observed in MCI
What This Means for Patients
What the research demonstrates is a link between glucosamine use and the pace at which knee osteoarthritis worsens, rather than proof that glucosamine itself brings about that acceleration. The 25% figures are the exact numbers presented by the investigators in their findings.
The death rate among people with ADRD stands out as a major concern. It rises by 25%, which represents a significant consequence.
The Next Step
Before any verdict can be reached on whether glucosamine causes harm, clinical trials are needed to establish whether there is an actual link. Until those trials are conducted, the association stands merely as a warning.
The bottom line for now is straightforward: glucosamine is a widely used supplement aimed at supporting joint health. New research suggests it might also have an effect on the brain.
Source material: “Glucosamine, a popular joint supplement, linked to faster Alzheimer’s progression,” ScienceDaily.
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