Ascorbic Acid

 Ascorbic Acid, the vitamin C we ingest with our food and multivitamins may not reach our skin in quantities high enough to do everything that vitamin C is supposed to do. Ascorbic acid (and derivatives that our body can use) protect us from free radicals like those formed during exposure of our skin to UVA and UVB radiation. Ascorbic acid is also necessary to synthesize collagen, where is required to hydroxylate the amino acid proline after synthesis of the protein. Scurvy is a syndrome of vitamin C deficiency and is related to defective collagen synthesis. Ascorbic acid is known to inhibit synthesis of melanin, probably because melanin is made by our skin in response to stress, and ascorbic acid is in the first line of defense, preventing the damage before melanin synthesis can be initiated. Ascorbic acid and its derivatives promotes wound healing, controls inflammation and reduces erythema. In short, ascorbic acid is a safe active that will bring multiple benefits to your skin, preventing future damage but also repairing past damage to your skin by age and sun.

The chemical name is Ascorbic Acid. Deficiency of Vitamin C results in scurvy, and the name “Ascorbic Acid” is derived from the Latin word for scurvy (scorbutus), a nasty illness whose (easy) fix, citrus fruit, eluded pirates and sailors until 1753.

Why is Ascorbic Acid a vitamin? Most animals can make their own vitamin C, but humans can’t, because somewhere along the line we lost a crucial enzyme required for the synthesis of Ascorbic Acid, making it an essential nutrient.

Ascorbic Acid is important for plants and animals because it works as an antioxidant. In humans and many animals it is also a cofactor in the synthesis of Carnitine and Tyrosine and is required for the synthesis of collagen.

Collagen is a protein of complex structure, very different from the peptides initially made by the ribosomes. It is composed of a triple helix, which consists of two identical chains (α1) and an additional chain that differs slightly in its chemical composition (α2). The amino acid composition of collagen is unusual for proteins, especially because of its high content of Hydroxyproline. The peptides synthesized in the ribosomes undergo many modifications of their structure before they become collagen. Among other modifications, the Proline and Lysine residues in the peptides must be hydroxylated, a process catalyzed by enzymes that require Ascorbic Acid as a cofactor. The many symptoms of scurvy result from the inability of the human body to complete the transformation of the nascent peptides into collagen because of this lack of Ascorbic Acid.

Why are “C Serums” so popular?

Like for all skin care products, there is probably an important marketing component, but the relevance of Vitamin C to skin metabolism is so great that it is not surprising that Vitamin C serums actually do what they are supposed to do, a rarity in the skin care industry.

Ascorbic Acid provides important protection against damage induced by UV radiation (and the DNA mutations and cancer that may result from it), improves skin elasticity, decreases wrinkles by stimulating collagen synthesis, reduces redness, promotes wound healing and suppresses melanin synthesis.

The effect of Ascorbic Acid on collagen synthesis is apparent, and the importance of collagen for skin health is paramount. Collagen fibers give the skin resistance to strain and traction. Collagen constitutes about 70% of skin mass, but total collagen decreases about 1% per year, what may look like a small decline, but in such a major component of the skin, it will affect skin volume and its physical properties. Also, aging changes collagen structure: what was an organized pattern in young skin, in older skin collagen can turn into thick fibrils arranged in disorganized bundles. It is not “only” quantity, then, it is also quality that matters. We know that aging decreases skin thickness and elasticity, and it is likely that collagen is a good part of the answer. If we care about slowing down and reversing skin aging, we should care about collagen too.

References: Put together by Dr. Sivak’s at Skin Actives

Kameyama K, Sakai C, Kondoh S, Yonemoto K, Nishiyama S, Tagawa M, Murata T, Ohnuma T, Quigley J, Dorsky A, Bucks D, Blanock K. (1996) Inhibitory effect of magnesium L-ascorbyl-2-phosphate on melanogenesis in vitro and in vivo. J Am Acad Dermatol. 34:29-33.

Kobayashi S, Takehana M, Itoh S, Ogata E. (1996) Protective effect of magnesium-L-ascorbyl-2 phosphate against skin damage induced by UVB irradiation. Photochem Photobiol. 1996 Jul; 64:224-8

Geesin JC, Gordon JS, Berg RA. (1993) Regulation of collagen synthesis in human dermal fibroblasts by the sodium and magnesium salts of ascorbyl-2-phosphate. Skin Pharmacol. 6:65-71.

                                            Ascorbic Acid

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