Tokyo, Japan — As the body ages, the skin’s protective outer layer, the epidermis, becomes thinner and less effective at shielding against external threats. Recent research sheds new light on the role of vitamin C, known for its antioxidant properties, in enhancing skin health through genetic mechanisms.
A study published in the Journal of Investigative Dermatology reveals that vitamin C not only strengthens the skin by promoting cell renewal but also reactivates specific genes responsible for skin regeneration. Dr. Akihito Ishigami, the study’s lead author and vice president of the Tokyo Metropolitan Institute for Geriatrics and Gerontology (TMGHIG), emphasized that the research focuses on how vitamin C influences epidermal growth. “We explored its effects on cell proliferation and differentiation through epigenetic modifications,” he stated.
Vitamin C, or ascorbic acid, is essential for various biological functions, including collagen synthesis, which is critical for maintaining the skin’s structural integrity. Unlike most animals, humans must obtain this vital nutrient from dietary sources, primarily fruits and vegetables such as oranges, kiwis, and bell peppers. In addition to its metabolic roles, vitamin C bolsters the immune system, aids in neurotransmitter production, and acts as a powerful antioxidant to combat free radicals.
In their investigation, researchers employed lab-grown three-dimensional skin models to assess the impact of vitamin C on skin growth. They applied two concentrations of the vitamin and observed significant changes over 14 days. Initially, the living layer of skin thickened, indicating an increase in keratinocyte production—the primary cells that form the skin barrier. By day 14, the thickness of the living layer continued to rise, while the outermost dead skin layer showed a reduction in thickness.
The findings indicate that vitamin C accelerates cell division, with treated samples displaying a higher presence of Ki-67-positive cells, a marker of active division. The study delves deeper into how vitamin C enhances skin regeneration by activating enzymes that stimulate gene activity and revert DNA methylation, a process that silences certain genes.
Through their experiments, researchers identified over 10,000 DNA regions that became less methylated after vitamin C treatment, leading to a 1.6 to 75.2-fold increase in the expression of 12 pivotal genes. When TET enzymes responsible for DNA demethylation were inhibited, the positive effects on skin thickening were reversed, confirming the significance of this process in keratinocyte growth.
The study attributes these results to vitamin C’s ability to promote gene expression by enhancing chromatin accessibility, allowing for greater interaction between transcription factors and DNA. This increase in chromatin openness surrounding growth-related genes further supports vitamin C’s role in epidermal development.
Additionally, long-read sequencing data confirmed that vitamin C boosts the production of full-length, functional gene transcripts, illuminating its ability to activate genes in a manner that produces usable proteins.
Dr. Ishigami noted that the implications of these findings point to vitamin C’s potential as a treatment for thinning skin, particularly in older adults. “We discovered that vitamin C aids in thickening the skin by stimulating keratinocyte proliferation through DNA demethylation,” he said.
As this research highlights the multifaceted benefits of vitamin C, it suggests that this nutrient may soon become a vital component in skincare routines, not just for its antioxidant effects, but also for its potential to rejuvenate skin at the genetic level.