Vitamin C linked to gray‑matter volume in Japanese seniors, while glucosamine may accelerate dementia progression

Researchers at Hirosaki University analysed MRI scans and plasma vitamin C levels of 2,044 Japanese adults aged over 64. They found that participants with lower vitamin C concentrations had, on average, reduced gray‑matter volume and weaker structural connectivity in the brain’s default mode network, a pattern associated with memory and attention. The observational study, published in PLOS One, does not prove that vitamin C prevents cognitive decline, but it highlights a notable association between circulating vitamin‑C status and measurable brain characteristics in older adults.

A separate investigation by the University of Florida examined electronic health records of patients with mild cognitive impairment or Alzheimer‑type dementia. Using AI‑driven analysis, the team reported that use of the over‑the‑counter supplement glucosamine was associated with a 25 % higher chance of progressing from mild cognitive impairment to dementia, and a 25 % increase in mortality among those already diagnosed with dementia. The authors caution that the findings show correlation rather than causation and suggest further clinical scrutiny of glucosamine’s metabolic effects on the brain.