Lower blood levels of vitamin C, a nutrient known for its immune-boosting properties, have been linked to reduced gray matter volume and weaker brain connectivity in older adults, according to a new study. These findings suggest a potential role for the vitamin in protecting the aging brain.
The study, published in the journal PLoS One, analyzed data from over 2,000 Japanese adults aged 70 and older. Researchers examined the relationship between vitamin C levels in the blood and brain structure, including gray matter volume and the connectivity of brain networks. Gray matter is crucial for cognitive functions such as memory, thought, and decision-making.
Participants with higher blood levels of vitamin C tended to have greater gray matter volume. Specifically, a small but statistically significant increase in gray matter volume was observed in individuals with higher vitamin C levels. The magnitude of this effect was found to be comparable to that of established risk factors for dementia, such as high blood pressure and smoking.
Furthermore, higher vitamin C levels were associated with stronger communication between different brain regions. The study found more robust connections within the default mode network, a set of brain areas involved in memory and self-reflection, in participants with greater vitamin C intake. This network is often affected early in Alzheimer's disease.
The research also identified a link between higher vitamin C levels and better-preserved brain tissue in specific areas, including the posterior cingulate cortex, which is among the first regions impacted by Alzheimer's. Other affected areas involved in emotional regulation, complex reasoning, and language processing also showed positive associations with vitamin C levels.
While the study highlights a correlation, researchers emphasize that it does not prove causation. Individuals with higher vitamin C levels often have healthier overall diets, which could contribute to the observed brain benefits. However, the findings contribute to a growing body of evidence supporting the connection between vitamin C and cognitive health.
The recommended daily intake of vitamin C is 90 milligrams for adult men and 75 milligrams for adult women. Smokers are advised to consume an additional 35 milligrams per day due to smoking's depleting effect on vitamin C stores. The nutrient is abundant in a variety of fruits and vegetables, including citrus fruits, strawberries, bell peppers, broccoli, and leafy greens.