Glucosamine, MSM and Alzheimer’s: What the 2026 Study Shows

It is not established that a glucosamine–MSM supplement causes Alzheimer’s disease. However, a 2026 study raises a concern about glucosamine in people who already have mild cognitive impairment or dementia: documented use was associated with more progression to dementia and poorer survival in people with established dementia. The human findings were observational, not proof that glucosamine caused those outcomes. The study did not evaluate MSM’s contribution or test a standardized glucosamine–MSM combination. Original study, Nature Metabolism

For someone with a cognitive diagnosis who takes a glucosamine-containing joint supplement, this is a reason to review the product with their clinician. For someone taking MSM alone, it is not evidence that MSM carries the same risk.

What the 2026 study actually found

In Hyperglycosylation is a metabolic driver of Alzheimer’s disease, University of Florida researchers combined brain-tissue analysis, mouse experiments and a retrospective review of UF Health records from 2012–2024.

The eligible health-record cohorts included 24,481 people with Alzheimer’s disease and related dementias (ADRD) and 41,884 with mild cognitive impairment (MCI). Of those, 1,896 and 2,750, respectively, had documented glucosamine use. Those smaller numbers were glucosamine users—not the total study populations. Related dementias included vascular, Lewy body and frontotemporal dementia, so the results should not all be described as Alzheimer’s-specific. Study results and methods

Researchers reported:

• A 25% relative increase in the proportion of people with MCI transitioning to ADRD among glucosamine users.
• A 25% higher mortality risk among glucosamine users with established ADRD.
• No significant mortality association in the MCI group.

The analyses accounted for age and demographic factors, with the methods describing matched user–nonuser comparisons. These are group-level associations, not a prediction of what will happen to an individual. A 25% relative increase also does not mean an additional 25 out of every 100 users will develop dementia. Study findings and methods

Crucially, the study’s human comparison was not between cognitively healthy supplement users and nonusers followed for new Alzheimer’s diagnoses. Its most relevant warning concerns people with an existing cognitive diagnosis.

Why the finding matters—and why it is not proof

The proposed mechanism involves glycosylation, the attachment of sugar structures to proteins. This is normal cell biology, but the researchers found excessive N-linked glycosylation in Alzheimer’s brain tissue and disease-model mice. Glucosamine can supply material to this pathway.

In Alzheimer’s-model mice, two weeks of oral glucosamine sulfate worsened social-recognition memory and increased glycosylation. Comparable treatment did not impair that memory measure or produce hyperglycosylation in normal mice. Those findings support a possible disease-dependent mechanism, but normal-mouse results cannot establish long-term safety in healthy people. Mouse experiments and discussion

The human analysis still has important limits. Researchers identified supplement exposure from clinical records, rather than assigning a standardized product and dose. Matching on demographics cannot eliminate all differences in health, medication use or supplement-taking behavior. The analysis does not establish a safe human dose, identify a safer glucosamine formulation, or show that stopping it reverses cognitive decline. Study methods

The investigators explicitly call for a double-blind clinical trial. UF Health likewise describes the findings as preliminary and an association rather than proof of causation. UF Health’s study report

Why some earlier research sounded reassuring

A 2023 UK Biobank study followed 494,814 participants without dementia at baseline for a median of 8.9 years. Its observational analysis associated regular glucosamine use with a lower incidence of Alzheimer’s disease: adjusted hazard ratio 0.83, with a 95% confidence interval of 0.71–0.98. That paper also called for randomized-trial validation. 2023 study, BMC Medicine

The two studies ask different questions: developing dementia in a population initially without dementia versus progression and survival after a cognitive diagnosis. Neither establishes that glucosamine should be used to prevent Alzheimer’s. The earlier association also does not cancel the newer concern in people with cognitive impairment.

What this means for MSM and combination products

Glucosamine and MSM—methylsulfonylmethane—are different ingredients. Being sold together does not make their evidence interchangeable.

• Glucosamine plus MSM: The product contains the ingredient implicated in the 2026 association. The study does not show that adding MSM prevents, increases or offsets that association.
• Glucosamine, chondroitin and MSM: This remains a glucosamine-containing product; the additional ingredients do not remove the concern.
• MSM alone: The glucosamine findings cannot be transferred to MSM. They also do not prove MSM is safe for long-term use in people with dementia.

Switching to plain MSM is therefore not an established dementia-risk reduction strategy. It changes ingredient exposure, but does not provide evidence of cognitive protection. NCCIH says very little research has been done on MSM for osteoarthritis, leaving its usefulness uncertain. NCCIH osteoarthritis overview

For the separate joint-pain question, see our assessment of glucosamine–chondroitin–MSM combinations.

What to do with your supplement label

If you or someone you care for has MCI, Alzheimer’s or another dementia diagnosis, bring the actual bottle—or clear photographs of the Supplement Facts panel—to the clinician managing their care. Record the serving size, amount taken each day, duration of use and any noticeable joint-pain benefit. Ask whether continuing glucosamine is worthwhile given this emerging concern and the available alternatives.

Include the full medication list. Separate from the dementia question, glucosamine and chondroitin have been associated with increased bleeding risk in people taking warfarin. NCCIH safety information

If you have no cognitive diagnosis, this study alone does not establish that your supplement increases your chance of developing Alzheimer’s. If you have new or worsening memory problems, seek an assessment rather than assuming the supplement is the cause—or that changing supplements will solve them.