A common over-the-counter supplement, glucosamine, may be associated with accelerated cognitive decline in individuals with Alzheimer’s disease and mild cognitive impairment, according to new research published in the journal Nature Metabolism.
The study found that people with Alzheimer’s disease who took glucosamine were 25% more likely to die within five years compared to those who did not. For individuals in the earlier stage of memory loss, known as mild cognitive impairment, taking glucosamine was linked to a 25% increased likelihood of progressing to full Alzheimer’s disease.
Researchers analyzed anonymized medical records from the University of Florida Health system, including data from 24,000 patients diagnosed with dementia and 41,000 with mild cognitive impairment. The analysis compared outcomes for patients taking glucosamine against those who did not.
Animal Studies Suggest Mechanism
To investigate the potential biological mechanism, the research team conducted experiments using mice engineered to exhibit Alzheimer’s-like symptoms. They observed that blocking the enzyme responsible for producing sugars like glucosamine appeared to improve dementia symptoms in these mice. Conversely, feeding glucosamine to the same mice worsened memory loss. Healthy mice that received the supplement showed no adverse effects.
The study’s authors noted that glucosamine is classified by the Food and Drug Administration as a dietary supplement, meaning it is available without a prescription. Glucosamine is an amino sugar composed of glucose and glutamine, used by the body for building new cells. While not an essential nutrient, it is widely taken for joint health.
The research team at the University of Florida has been studying sugar processing in the brain and its relation to Alzheimer’s disease for over a decade. They noted that brain cells and proteins in individuals with Alzheimer’s can develop abnormal sugar coatings, a condition known as hyperglycosylation. This excess sugar buildup can lead to protein dysfunction, memory loss, and cell death.
Potential Harm for Compromised Brains
Given that millions of older Americans live with Alzheimer’s disease and many also take glucosamine for joint issues, the researchers hypothesized that the supplement might contribute to cognitive decline in this population. While previous studies have suggested a lower dementia risk from glucosamine in cognitively healthy adults, this new research indicates that the supplement may be harmful to brains already experiencing cognitive impairment.
The study’s authors cautioned that their findings, based on patient records, establish an association rather than direct causation. A controlled human trial would be needed to confirm causality, but such a study would raise ethical concerns if glucosamine is potentially harmful. Further research is also needed to determine if dosage, brand, or duration of use impacts the observed effects, and whether the findings extend to other forms of dementia.
The team plans future studies, including tracking dementia patients who have discontinued glucosamine to see if their cognitive decline slows. They are also screening compounds that could block sugar buildup on brain cells and exploring whether other supplements processed similarly to glucosamine might pose comparable risks.
Mitchell Landsberg is the senior reporter for News Raise and focuses on Technology. Mitchell regularly writes about social media platforms and how influencers, industry and general people use them to communicate and make money.
