Glucosamine is one of the most popular supplements in America — sold over the counter at every pharmacy and grocery store, taken daily by tens of millions of older adults for joint pain and osteoarthritis, and generally considered so routine that most people never mention it to their doctor. A major study published June 9, 2026, in Nature Metabolism now raises a significant question about whether that routine habit is safe for people with early cognitive decline.
Researchers at the University of Florida found that people with mild cognitive impairment (MCI) who reported taking glucosamine were 25% more likely to progress to full Alzheimer's disease than those who did not. For patients already diagnosed with Alzheimer's disease and related dementias (ADRD), glucosamine use was also linked to a 25% higher risk of mortality within a specified follow-up period.
