According to a recent study, vitamin C significantly reduces skin ageing at the cellular and genetic level.

Our skin serves as our initial line of defence. The epidermis, the outermost layer, thins over time. It is no longer able to prevent external damage. The majority of this layer is made up of keratinocytes, which migrate upward to form the skin's barrier.

In addition to its well-known antioxidant properties, vitamin C (VC) has been extensively researched for its potential to heal skin. Recent studies give its significance a more profound genetic component.

Vitamin C thickens the skin by reactivating some genes, according to a Japanese study that was published in the Journal of Investigative Dermatology. By promoting cell renewal through epigenetic modifications, it fortifies the skin.

According to Dr. Akihito Ishigami, Vice President at the Tokyo Metropolitan Institute for Geriatrics and Gerontology (TMGHIG), who oversaw the study, "VC appears to affect the structure and function of epidermis, particularly by regulating the growth of epidermal cells."

"In this study, we examined whether it stimulates cell differentiation and proliferation through epigenetic modifications."

The fundamentals of understanding vitamin C

Vitamin C, also referred to as ascorbic acid, is a vital component in many enzyme activities and a potent antioxidant that is vital to human development. Collagen, a crucial structural protein present in skin, blood vessels, and connective tissues, is produced by the body using it.

It also helps with the metabolism of some amino acids and the synthesis of neurotransmitters like norepinephrine. Humans must absorb vitamin C through their food, mostly from fruits and vegetables like oranges, kiwis, strawberries, bell peppers, and broccoli, since they are unable to synthesise it internally like most other species can.

In addition to its structural and metabolic functions, vitamin C boosts skin barrier defences and supports white blood cell function, which both improve the immune system. Its antioxidant qualities aid in scavenging free radicals, which may reduce the risk of long-term conditions, including cancer and heart disease.

How skin thickens due to vitamin C

The effect of vitamin C on skin growth was the focus of the study. However, they developed lab-grown skin known as human epidermal equivalents rather than testing on actual human skin. The behaviour of these 3D skin models is similar to that of actual skin.

In these models, the top layer is exposed to air, like human skin, exposing the environment, while the bottom layer absorbs nutrients, just as blood vessels nourish real skin from underneath.

They used 0.1 and 1.0 millimolar dosages of vitamin C. Seven days later, they saw that the skin's live portion thickened, indicating that additional skin cells had proliferated.

At this stage, the outermost layer of dead skin remained unchanged. However, by day 14, the outer dead layer had thinned, and the living layer had thickened even more.

This implied that the skin was producing more keratinocytes—the primary cells responsible for creating the protective barrier—as a result of vitamin C.

Cell division is accelerated by vitamin C.

Vitamin C-treated samples exhibited faster skin regeneration and more Ki-67-positive cells, which are indicators of active division. The scientists next investigated how this increase was made possible by vitamin C.

Through the activation of enzymes that aid in gene activation and DNA demethylation, vitamin C stimulates epidermal regeneration by reactivating genes involved in cell proliferation. This process ultimately improves keratinocyte growth and results in thicker, healthier skin.

They found that by eliminating methyl groups from DNA, vitamin C reactivates important genes. Genes are silenced by these methyl groups. When they are removed, the genes become active, encouraging the growth and repair of skin cells.

DNA demethylation is carried out by TET enzymes, which unlock repressed genes. 5-methylcytosine is changed into 5-hydroxymethylcytosine by them.

Iron in the Fe2+ state is needed for this step. The process halts when iron turns into Fe3+. The process is maintained by vitamin C, which contributes electrons to convert Fe3+ back into Fe2+.

Over 10,000 regions of DNA that were hypomethylated with vitamin C were found in the study. Twelve important genes saw increases in expression ranging from 1.6 to 75.2 times.

The effects were reversed when TET enzymes were blocked. This demonstrated how TET-mediated demethylation contributes to skin thickening.

Alterations in DNA activity and structure

Additional tests are included in the manuscript to corroborate these findings. It explains how vitamin C increases chromatin accessibility, which in turn enhances transcriptional activation.

Increased chromatin openness surrounding growth-promoting genes was seen in skin treated with vitamin C.

The study demonstrates that open chromatin areas close to cell proliferation-related gene bodies are enriched. The development of the epidermis depends on these genes.

It further demonstrates the effects of vitamin C by showing that genes including DLX5, CXCL14, and EFNA1 are upregulated. These genes support the organisation of the skin's structure and the proliferation of keratinocytes.

Additionally, long-read sequencing data is presented in the publication. This method verified that full-length, functional gene transcripts are expressed more when vitamin C is present. This supports the notion that vitamin C produces useful proteins in addition to activating genes.

Vitamin C works nicely for older skin.

These results imply that vitamin C helps fortify ageing or weak skin. Restarting growth pathways that deteriorate with age is how it functions. At the molecular level, it promotes cellular reconstruction and reactivates genes.

"VC is a promising treatment for thinning skin, especially in older adults, as we found that it helps thicken the skin by encouraging keratinocyte proliferation through DNA demethylation," Dr. Ishigami says.

Because of this study and all the others that came before it, vitamin C may soon be used more frequently in skincare regimens as a genetic rejuvenator in addition to an antioxidant.