Overview
- The PLOS One study, published Wednesday, June 10, 2026, analyzed MRI scans and a single plasma vitamin C measurement from 2,044 Japanese adults aged 65 and older and found lower vitamin C was associated with lower gray matter volume and reduced connectivity in the brain's default mode network.
- Researchers adjusted for age, physical activity and education and measured gray and white matter volumes plus connectivity across the default mode network, a set of brain regions tied to memory and attention.
- The paper's authors and independent experts emphasize the results show an association not proof of cause and effect, so the finding does not change clinical guidance or prove supplements will protect memory.
- Study limitations include one-time blood measurements, possible residual confounding from diet and health, and a geographically and ethnically narrow sample, prompting calls for repeated measures, broader lifestyle controls, and more diverse cohorts.
- If later studies confirm causality, the finding could prompt trials of dietary or supplement interventions and influence public health advice on fruit and vegetable intake as a low-cost strategy to support healthy brain aging.