Study finds link between vitamin C deficiency and reduced brain health

Findings from a new study suggest that older adults with lower levels of vitamin C in their blood tend to have less grey matter and weaker connectivity in brain regions involved in memory and attention.

The large-scale study, led by Japanese researcher Haruka Nagaya of Hirosaki University, adds to growing evidence that nutrition may play an important role in brain aging, as a Newsweek article highlights.

Researchers analyzed MRI brain scans and blood plasma samples from 2,044 Japanese adults aged 64 and older, measuring gray and white matter volumes as well as connectivity within the brain's default mode network—a system of interconnected regions associated with memory, self-reflection, and attention.

After accounting for factors including age, education, and physical activity, the researchers found that participants with lower blood concentrations of vitamin C consistently had reduced gray matter volume and weaker connectivity within the default mode network.

Commenting on the findings, New Jersey-based neuropsychologist Dr. Jessica McCarthy told Newsweek that the study's significance lies not only in the association itself, but also in the specific brain systems involved.

"We have historically thought about Alzheimer's in the context of brain localization—meaning that change occurs in the brain because specific regions of the brain are impacted, like the hippocampus, which is responsible for converting short-term memory into long-term storage, and the frontal lobe, which is responsible for the executive functions," McCarthy said.

She noted that the researchers instead found links between vitamin C levels and broader indicators of brain health.

"However, the researchers found associations instead with greater gray matter volume—which can be thought of as the 'meat and potatoes' of the brain—and stronger connectivity within the default mode network."

"Increasingly, we're recognizing that many neurodegenerative diseases are disorders of brain networks, not just isolated structures."

Grey matter contains the neuron cell bodies responsible for functions such as memory, attention, language, and decision-making. Although some loss of gray matter is a normal part of aging, accelerated decline has been associated with mild cognitive impairment, Alzheimer's disease, and other forms of dementia.

The default mode network is one of the brain's primary communication systems and is among the earliest networks to be disrupted in Alzheimer's disease.

While the study identified a clear association, the researchers emphasized that it does not prove vitamin C directly protects the brain.

"While this study cannot tell us whether vitamin C preserves grey matter, it raises an intriguing possibility that lifestyle choices such as consumption of foods rich in vitamin C may help," McCarthy said.

By Nazrin Sadigova