A Japanese brain-imaging study found that older adults with lower plasma vitamin C levels had reduced gray matter volume and weaker connectivity in a brain network linked to memory and self-reflection, though researchers said the findings show association, not causation.
By yourNEWS Media Newsroom
Older adults with lower blood levels of vitamin C may have reduced gray matter volume and weaker connectivity in an important brain network, according to a new study published in PLOS One.
The cross-sectional study analyzed approximately 2,000 Japanese adults aged 64 and older who participated in the Iki-Iki Health Promotion Project, a community-based research effort in Hirosaki City, Japan, focused on dementia and cardiovascular disease risk factors [1].
Researchers examined fasting blood samples and brain MRI scans to compare plasma vitamin C concentrations with brain structure and functional connectivity. Participants with lower vitamin C levels showed lower gray matter volume and reduced connectivity in the default mode network, according to the study [1][8].
Gray matter is brain and spinal cord tissue involved in memory, movement, thinking and information processing [2].
The study was led by Dr. Tomohiro Shintaku, an assistant professor in the Department of Radiology at Hirosaki University. Researchers reviewed data from about 2,390 initial participants, with just over 2,000 meeting criteria for the final analysis [1].
The research team measured vitamin C concentrations in blood plasma and used MRI scans to evaluate gray matter volume, white matter volume and connectivity within the default mode network [8].
The default mode network, or DMN, is a group of brain regions that becomes more active when the brain is at rest. It is associated with short-term memory, introspection and self-referential thinking.
The researchers found that lower plasma vitamin C levels were consistently associated with lower gray matter volume and weaker DMN connectivity compared with higher vitamin C levels [1].
Vitamin C is a water-soluble antioxidant that humans must obtain through diet because the body cannot produce it. The study authors noted that vitamin C levels in the brain are more than twice as high as those found in the blood, underscoring its potential importance to central nervous system health [1].
Previous research has suggested that nutrients, including vitamin C, may contribute to healthy brain aging. The new findings add evidence linking vitamin C status with measurable brain-imaging outcomes [2].
Books such as “This Is Your Brain on Food” have also examined how nutrients may influence mental well-being and brain function [3].
The authors cautioned that the study does not prove vitamin C prevents cognitive decline or that supplementation would improve brain health. Because the research was cross-sectional, it captured data at one point in time and can only show associations [8].
Still, the findings support the broader idea that adequate nutrition may be one factor involved in maintaining brain health during aging.
Experts cited in coverage of the study noted that the default mode network plays an important role in memory and self-awareness. Reduced connectivity in this network has been identified as an early sign of cognitive impairment [1].
The researchers said maintaining healthy vitamin C levels through diet may be a reasonable approach, but they did not recommend high-dose supplements based on this study alone.
Vitamin C is found in many fruits and vegetables, including lemons, lychee and parsley [4][5][6]. Lemons provide vitamin C and antioxidant flavonoids that may support cardiovascular health [4]. Parsley contains vitamins K, A and C, along with minerals such as calcium and iron [6].
The study authors suggested that a balanced dietary pattern that includes vitamin C-rich foods is more appropriate than immediately turning to high-dose supplementation [1].
Several limitations remain.
The study population was relatively homogeneous, consisting of older Japanese adults from one geographic region [8]. Researchers said the findings should be replicated in more diverse populations before broader conclusions are drawn.
Shintaku also called for longitudinal studies that track changes in vitamin C levels, brain structure and cognitive outcomes over time [1]. He said future research should include more comprehensive lifestyle data, including body mass index, total dietary intake and other factors that could influence brain health [8].
The authors also recommended that future studies use repeated vitamin C measurements, detailed dietary assessments and better controls for socioeconomic status and overall diet quality.
Randomized clinical trials would be needed to determine whether improving vitamin C status through diet or supplementation can directly affect brain structure, connectivity or cognitive function.
The study adds to growing research on how nutrition may influence brain aging, but it does not establish vitamin C as a standalone treatment or preventive measure for cognitive decline.
Researchers said the best current takeaway is that maintaining adequate vitamin C intake as part of a healthy dietary pattern may support overall brain health, along with other habits such as regular exercise and social engagement.
As populations age, the authors said identifying modifiable lifestyle factors linked to brain function could become increasingly important for public health.
Source: Natural News
Original article
Comments