Is there a link between glucosamine and dementia?

Glucosamine, a supplement commonly used for joint health, has been linked to a higher risk of mild cognitive impairment progressing to dementia in older adults with existing memory and thinking difficulties, according to a new study. Published in Nature Metabolism, the research conducted at the University of Florida examined patient records alongside experiments involving mice and human brain tissue.

While the findings suggest a 25% higher likelihood of progression to dementia among glucosamine users with mild cognitive impairment, the study does not establish a direct cause-and-effect relationship. The researchers found that glucosamine use was associated with a higher risk of death during follow-up in patients already diagnosed with Alzheimer’s disease or related dementias.

However, the link was not observed in the mild cognitive impairment group. The study highlights the need for further investigation, as the association between glucosamine use and dementia risk is an association, not proof of causality. The researchers also explored a possible explanation in the laboratory, finding that older adults with memory or thinking difficulties have an overactive process that attaches sugar structures to proteins, which becomes more pronounced in Alzheimer’s disease.

Glucosamine, which occurs naturally in the body and can cross the barrier between the bloodstream and the brain, helps fuel this process. However, the study's results in mice cannot be directly translated to humans, and more human clinical trials are needed to draw definitive conclusions about the supplement's effects. People with diagnosed cognitive impairment or dementia should discuss their glucosamine use with their doctor or pharmacist when reviewing their medicines and supplements.