A large Japanese study involving more than 2,000 adults over 64 found that those with lower blood levels of vitamin C tended to have less gray matter and weaker connectivity in the default mode network — a brain network critical for memory and attention. Researchers used MRI scans and blood plasma analysis to identify these associations after adjusting for age, education, and physical activity. While the study cannot prove that vitamin C directly protects the brain, it adds meaningful weight to the growing body of evidence suggesting that nutrition plays a role in how the brain ages. The researchers call for follow-up trials to confirm causality and explore the biological mechanisms involved.
