A vitamin commonly found in fresh fruits and vegetables may hold the key to combating one of the visible signs of aging: thinning skin. A groundbreaking study has revealed that vitamin C can significantly increase epidermal thickness in lab-grown human skin models by reactivating genes associated with cell growth.
Conducted by researchers in Japan and led by pharmaceutical scientist Yasunori Sato of Hokuriku University, the study demonstrates that vitamin C concentrations typically delivered to human skin via the bloodstream are sufficient to produce a measurable effect. This discovery positions vitamin C as a potential tool for mitigating some of the aging impacts on our largest organ.
Vitamin C’s Role in Skin Health
Biologist Akihito Ishigami of the Tokyo Metropolitan Institute for Geriatrics and Gerontology explains, “Vitamin C seems to influence the structure and function of the epidermis, especially by controlling the growth of epidermal cells. We investigated whether it promotes cell proliferation and differentiation via epigenetic changes.”
Healthy human skin contains high levels of vitamin C, hinting at active accumulation, whereas aged or UV-damaged skin shows lower concentrations. Known for boosting collagen production, alleviating UV damage, and providing antioxidant protection, vitamin C plays a crucial role in skin health.
According to the study, “Vitamin C helps thicken the skin by encouraging keratinocyte proliferation through DNA demethylation, making it a promising treatment for thinning skin, especially in older adults.”
Understanding the Mechanism
Vitamin C’s influence extends to the demethylation of DNA, a process crucial for genetic stability and gene expression. The addition or removal of methyl groups acts as a molecular switch to turn gene activity on or off without altering the genomic sequence. However, the role of demethylation in the differentiation of keratinocytes, the predominant cells in the human epidermis, was previously unclear.
Keratinocytes form at the bottommost layer of the epidermis and gradually move upward as they mature, eventually becoming the dead cells that constitute the skin’s outermost layer, the stratum corneum. This layer, composed entirely of dead cells, serves a protective function for the live skin cells beneath.
Research Methodology and Findings
To explore vitamin C’s impact on skin health, researchers cultivated human keratinocytes in petri dishes, exposing the upper layer to air and feeding it with a nutrient solution from below, mimicking the behavior of living human skin. They added vitamin C concentrations consistent with those delivered by the circulatory system into the nutrient solution, while a control group was grown without vitamin C.
After one week, the vitamin C-nourished models exhibited a thicker layer of living epidermal cells than the control group, with no effect observed on the stratum corneum. After 14 days, the epidermal cell layer was even thicker, and the stratum corneum showed thinning, indicating that vitamin C was promoting cell proliferation.
The researchers found that “under the influence of vitamin C, the expression of 12 key proliferation genes in the samples increased, some by as much as 75 times.”
Implications for Anti-Aging Treatments
By sequencing the DNA and RNA of their samples, the researchers traced this cell proliferation to demethylation, seemingly mediated by vitamin C sustaining the function of enzymes that regulate gene activity through demethylation. These enzymes require a specific form of iron to function, and vitamin C helps regenerate that form of iron, effectively reactivating genes associated with cell proliferation.
When an inhibitor was applied to the enzyme, the effect was reversed, confirming that vitamin C operates through this specific pathway. These findings suggest that vitamin C may be instrumental in developing treatments to counteract aging effects.
Future Directions
The research, published in the Journal of Investigative Dermatology, opens new avenues for anti-aging skin treatments. As scientists continue to explore vitamin C’s potential, its role in skin health could lead to innovative therapies for aging populations.
With its ability to thicken the skin and promote cell growth, vitamin C emerges as a promising candidate for future dermatological applications. As the scientific community delves deeper into its mechanisms, the potential for vitamin C to revolutionize skincare treatments remains a topic of significant interest.
