A commonly used over-the-counter joint supplement, glucosamine, has been linked in new research to faster cognitive decline in certain individuals. A study published in Nature Metabolism suggests a possible connection between glucosamine use and a 25% increased risk of progression from mild cognitive impairment (MCI) to Alzheimer’s disease. Researchers from the University of Florida examined more than a decade of electronic health records to explore long-term neurological outcomes associated with widely used supplements among older adults.
The analysis found that individuals with MCI who regularly used glucosamine were more likely to develop Alzheimer’s disease compared to non-users. The study also reported that among patients already diagnosed with dementia, glucosamine use was associated with a 25% higher risk of mortality. Scientists propose that this may be related to the supplement’s interaction with brain metabolism, particularly pathways involved in protein “sugar-tagging,” which can become disrupted in neurodegenerative conditions.
Researchers emphasize that these risks appear mainly relevant to people already experiencing cognitive decline. In cognitively healthy adults, previous studies have shown glucosamine may have neutral or even potentially protective effects. However, given its widespread use—especially among older adults managing joint pain and early memory issues—the findings highlight the importance of further investigation into its safety in vulnerable populations.
Experts caution that the results are preliminary and not definitive proof of harm for all users. They stress the need for controlled clinical trials to better understand the relationship between glucosamine and brain health. Until clearer evidence is available, individuals with cognitive concerns are advised to consult healthcare professionals before continuing long-term supplementation.