Individuals diagnosed with Alzheimer’s who used the popular supplement glucosamine faced a 25 percent higher chance of death within five years compared with non-users. This result emerged from research published in Nature Metabolism by scientists at the University of Florida. Glucosamine, an over-the-counter product marketed for joint discomfort and arthritis, is consumed annually by more than 40 million Americans. The same pattern appeared among people experiencing mild cognitive impairment, where users showed a 25 percent greater likelihood of advancing to full Alzheimer’s. Researchers examined anonymized records covering 24,000 dementia patients and 41,000 individuals with mild cognitive impairment within the University of Florida Health system. Parallel tests in mice genetically altered to display Alzheimer’s-like traits revealed that inhibiting the enzyme responsible for producing sugars such as glucosamine eased symptoms, whereas administering the supplement intensified memory problems. Healthy mice showed no change. Because the Food and Drug Administration treats glucosamine as a dietary supplement rather than a medication, it remains available without prescription. The compound consists of glucose combined with glutamine and supports cell construction, yet deficiency is not medically recognized. The team has long investigated sugar metabolism in the brain and noted that Alzheimer’s involves excess sugar attachments on proteins, known as hyperglycosylation, which disrupts cell function. Earlier observations had associated the supplement with reduced dementia risk in healthy adults; the current findings indicate potential harm only after cognitive decline begins. The observational design prevents establishing direct causation. Additional uncertainties include dosage, brand variations, duration of use, and applicability to other dementias. Planned follow-up will track patients who discontinued glucosamine to assess any slowing of decline. Separate efforts will test compounds that limit sugar buildup on brain cells and examine whether similar supplements pose comparable risks.
