Scientists discover a surprising link between vitamin C and brain health
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- Hirosaki University researchers analyzed MRI scans and blood plasma from 2,044 Japanese adults over age 64, finding that lower plasma vitamin C levels correlated with reduced gray matter volume and weaker connectivity in the default mode network.
- The study, published in PLOS One on June 10, 2026 and led by Haruka Nagaya, adjusted for age, education level, and physical activity before identifying the vitamin C–brain structure pattern.
- The default mode network, a group of interconnected regions central to attention and autobiographical memory, showed measurably weaker structural connectivity in participants with lower vitamin C levels.
- Researcher Tomohiro Shintaku said the findings generate the hypothesis that vitamin-C-rich diets might support brain health and help mitigate age-related cognitive decline in older adults.
- The authors cautioned that the observational design cannot prove vitamin C directly causes the brain differences, and recommended longitudinal studies with more diverse populations.
- Funding came partly from KAGOME CO., LTD., which paid salaries for two co-authors, and from Japan Agency for Medical Research and Development grants JP16dk0207025 and JP21dk0207053.
Why it matters: Among studies linking diet to brain aging, this one stands out for measuring vitamin C directly in blood plasma alongside MRI scans across 2,044 older adults, rather than relying on self-reported dietary recall as prior research has. The scale and methodology strengthen — without proving — the case that nutrition plays a role in preserving gray matter and memory-related brain networks late in life.
