India, June 21 -- A study of 2,044 older Japanese adults found that those with lower vitamin C levels in their blood plasma tended to have a lower volume of grey matter in their brains, as well as lower connectivity amongst a collection of brain regions known as the default mode network. Haruka Nagaya of Hirosaki University, Japan, and colleagues present these findings in the open access journal PLOS One on June 10, 2026.

To help fill that gap, Nagaya and colleagues analyzed magnetic resonance imaging (MRI) scans and plasma vitamin C levels of 2,044 Japanese adults over the age of 64.

Specifically, they measured the volume of each participant's gray and white brain matter (accounting for individual differences in total brain volume betw...