Scientists Discover Vitamin C's Unexpected Role in Supporting Brain Health

Higher blood levels of vitamin C may be associated with healthier brain structure and stronger brain connectivity in older adults, according to a study published in PLOS ONE. While the findings do not prove that vitamin C prevents cognitive decline, they add to growing evidence that nutrition may influence brain health during aging.

Researchers from Hirosaki University in Japan analyzed data from 2,044 adults aged 64 years and older. Participants underwent magnetic resonance imaging (MRI) scans and provided blood samples to measure plasma vitamin C levels. The team examined gray matter volume, white matter volume, and connectivity within the brain's default mode network (DMN), which plays a key role in memory, attention, and other cognitive functions.

After accounting for factors such as age, education, and physical activity, the researchers found that participants with lower vitamin C levels tended to have reduced gray matter volume and weaker connectivity within the DMN. Gray matter contains most of the brain's nerve cell bodies and is essential for processing information, while the DMN helps coordinate higher-order thinking and memory-related activities.

The researchers suggest that maintaining adequate vitamin C levels may help preserve brain structure and function as people age. However, they caution that the study was observational and cannot determine whether low vitamin C directly causes these brain changes. Other lifestyle and health factors could also contribute to the observed associations.

Although more research is needed, the findings support the idea that everyday dietary habits may play an important role in healthy brain aging. A balanced diet that provides sufficient vitamin C could potentially contribute to maintaining brain health, but clinical trials will be required to determine whether increasing vitamin C intake can directly reduce age-related cognitive decline.

REFERENCE: Haruka Nagaya, Keita Watanabe, Tomohiro Shintaku, Miho Sasaki, Jusei Kudo, Sera Kasai, Yuka Ishimoto, Kana Saito, Shuichi Matsuhashi, Taiki Koshiishi, Mizuki Imura, Amo Ozawa, Saaya Mori, Daisuke Watanabe, Shin Shukunobe, Tatsuro Sasaki, Soichiro Tatsuo, Shinya Kakehata, Tatsuya Mikami, Daichi Kokubu, Yusuke Ushida, Shingo Kakeda. Plasma vitamin C levels are associated with brain structural networks on MRI: A large cohort study. PLOS One, 2026; 21 (6): e0348504 DOI: 10.1371/journal.pone.0348504