Vitamin C Levels May Be Tied to Better Brain Health Later in Life

Orange juice for breakfast or a leafy green salad for lunch will net you a healthy dose of vitamin C — which could be boosting your brain health.

“Our most significant finding is that older adults with higher levels of vitamin C in their blood tend to have better-preserved brain structure,” says study author Tomohiro Shintaku, MD, PhD, as assistant professor of radiology at the Hirosaki University Graduate School of Medicine in Japan.

Higher Blood Levels of Vitamin C Linked to Higher Gray Matter Volume and Brain Connectivity

The study, published in PLoS One, included more than 2,000 adults from Japan who were 69 years old on average.

Researchers used blood tests to measure plasma vitamin C levels, and magnetic resonance imaging (MRI) to measure gray and white brain matter and total brain volume.

They also examined connectivity levels of each participant's default mode network, or DMN, which is “highly active during rest and plays an essential role in cognitive functions such as memory,” Dr. Shintaku says.

The analysis accounted for other factors that could affect brain structure and connectivity, such as age, physical activity, diabetes, and high blood pressure.

Results showed that participants with higher plasma vitamin C levels tended to have more gray matter volume and more connectivity in their default mode network than peers who had less vitamin C circulating in their blood.

“Our findings suggest that a lifelong habit of maintaining optimal vitamin C levels, through everyday diet, could be a simple yet powerful way to support brain health as we age,” says Shintaku.

It’s important to note that the study is observational, so it can only show a link, not a cause-and-effect relationship. It also doesn’t point to any optimal vitamin C level or range.

The Role of Vitamin C and Brain Health

Vitamin C is an antioxidant that supports blood vessel health in the heart and brain, says Majid Fotuhi, MD, a neurologist and author of The Invincible Brain. Dr. Fothui was not involved with the research. It helps protect neurons in the brain from oxidative damage, supports healthy blood flow (which brain cells depend on), and plays a role in producing neurotransmitters that regulate mood, attention, and memory, he explains.

“To the best of our knowledge, our study is the first to demonstrate a clear association between plasma vitamin C levels and the structural connectivity of the DMN,” Shintaku says.

Fothui says that “It makes biological sense that people with higher vitamin C levels might show modest benefits in brain structure.”

What’s significant to him about the new study is the connection between blood vitamin C levels and the default mode network, “the brain’s internal communication system for memory and self-awareness,” he says. The DMN is one of the first brain regions to break down in Alzheimer’s disease, he adds.

The Study Has Limitations

Researchers used a single blood draw for each participant to measure plasma vitamin C. They noted that the levels can vary throughout the day, and samples were collected after an overnight fast to minimize short-term dietary impacts. Since humans rely on dietary intake of vitamin C, this could impact the results.

Participants included older residents of Japan with a high educational background, and the results may not be applicable to other groups with different socioeconomic backgrounds.

Researches accounted for some lifestyle factors, like smoking, physical activity, and alcohol consumption, but not for others like total dietary intake, body mass index, or income, which could also impact results.

These Fruits and Vegetables Provide Ample Vitamin C

While the research is a “meaningful step forward,” Fotuhi says it doesn’t mean consuming vitamin C will necessarily grow your brain or protect your memory.

“What this study tells us is that maintaining good nutritional status, including vitamin C from food, may be one small piece of a much larger puzzle,” he says.

• Citrus fruits like oranges and grapefruits
• Kiwis
• Mangoes
• Red and green peppers
• Broccoli
• Cauliflower
• Brussels sprouts
• Spinach and other leafy greens

If your diet is limited or inconsistent and you’re not sure you’re getting enough vitamin C, a supplement might be a good idea, but it’s important to your doctor first.

The “strongest foundation for brain health” involves regular exercise, a diet rich in plants and omega-3 fatty acids, quality sleep, stress management, and cognitive engagement, Fotuhi says. “Vitamin C fits naturally into the diet pillar.”