Higher levels of vitamin C were linked to healthier brain structures in older adults, according to new research from Japan published in the journal PLOS ONE.
The observational study, conducted in Hirosaki City, included 2,044 participants with an average age of 69. Researchers measured blood plasma vitamin C levels and performed MRI scans to calculate gray and white matter volumes.
Even after adjusting for age, smoking, and diabetes, participants with lower vitamin C had reduced brain tissue volume and weaker structural network patterns, particularly in the default mode network (DMN) - a region vital for memory and often affected by Alzheimer’s disease.
“Our study demonstrates that older adults with higher blood levels of vitamin C tend to have better-preserved brain structure and stronger connections within the default mode network,” said Tomohiro Shintaku, MD, PhD, assistant professor in the Department of Radiology at Hirosaki University.
Researchers emphasized the study is observational and does not establish a cause-and-effect relationship. Other limitations include a single blood measurement per participant and a cohort composed almost entirely of older Japanese adults, limiting broader generalization.
"It is best viewed as a signal that vitamin C status may be one piece of a much larger brain-health picture," noted Dung Trinh, MD, an internal medicine physician.
Maintaining optimal vitamin C levels through a diet rich in citrus fruits, berries, tomatoes, and leafy greens could be a simple way to support brain health as we age.