Is My Expensive Vitamin C Serum Killing My Skin?

I am on my soapbox tonight.....

I recently came across an article titled "Is My Expensive Vitamin C Serum Killing My Skin".  The link is below.  There is nothing like someone masquerading as an expert only to find that really they aren't one at all.

Supposed skin guru expert Felicia Rose states that Ascorbyl Palmitate should not be used in cosmetics.  Not only does she wrongly make this assumption, to add insult to injury she also incorrectly categorizes Ascorbyl Tetraisopalmitate into the same bracket, despite no evidence of any research.  Her major point is below.

What this article infers is that Ascorbyl Palmitate generates free radicals and that it results when exposed to UV light causes a massive increase in skin cell death.

So is there any truth to this?

The answer is NO.  But first lets examine where this rumour came came from.  The rumour came from this study : “Vitamin C-Induced Decomposition of Lipid Hydroxyperoxides to Endogenous Genotoxins“.

This study shows that lipid hydroperoxides (rancid fat molecules) can react with vitamin C to form products that could potentially harm DNA.  Now here’s the kicker….these results of DNA damage were not demonstrated in the study.  It was suggested that vitamin C can form genotoxins (DNA-damaging agents) from lipid hydroperoxides, the implication being that vitamin C may enhance mutagenesis and the risk of cancer.

However, such a conclusion would be unwarranted.  Why?

The study is a test tube experiment.  The study does not, however, describe biochemistry or biology, and its relevance to reactions occurring in cells and tissues of the human body is unknown. Many reactions of vitamin C occur in vitro (in the test tube) that will not and cannot occur in vivo (in the living organism). Why? Because the physiological environment of the cell and the body contains thousands of substances that also react with vitamin C and lipid hydroperoxides, “derailing” the chemistry observed in a test tube system.

For example, lipid hydroperoxides don’t just wait around in vivo to bump into a vitamin C molecule, but instead are very rapidly reduced to harmless “alcohols” by a number of enzymes. Thus, the reaction rate of lipid hydroperoxides with these enzymes compared to the reaction rate of the lipid hydroperoxides with vitamin C is of crucial importance. Curiously, the reaction rate of lipid hydroperoxides with vitamin C was not measured in the Science study. From what we know from the study, incubations were done for two hours, an eternity in biochemical terms. Enzymatic reactions as those indicated above to reduce lipid hydroperoxides to harmless alcohols that do not react with vitamin C usually take a fraction of a second, not two hours!

Other studies like this one : “A short overview of vitamin C and selected cells of the immune system”  have  shown that vitamin C effectively inhibits the formation of lipid hydroperoxides in the first place. Thus, when human plasma is exposed to oxidizing conditions, vitamin C forms the first line of antioxidant defense, and no lipid hydroperoxides are formed. Lipid hydroperoxides begin to form only after vitamin C has been exhausted. Thus, in these experiments lipid hydroperoxides and vitamin C did not co-exist in human plasma, and thus never had the opportunity to react with each other! What’s more, the Science study used a concentration of lipid hydroperoxides of 400 µM, which in biochemical terms is “a ton.” Studies have shown that in human blood, lipid hydroperoxides may exist in concentrations of about 10 – 40 nM, which is 10,000-fold lower than what was used in the Science experiment. Again, this casts serious doubt on the relevance of these results for living organisms.

The next comment is comparing Ascorbyl Palmitate to Ascorbyl Tetraisopalmitate.  First Ascorbyl Tetraisopalmitate is it's INCI name.  It's chemical name is L-Ascorbic acid, 2,3,5,6-tetrakis(2-hexyldecanoate).  So whilst it may look similar from an INCI name, they are not.  The chemical is a tetraester of L-ascorbic acid and isopalmitic acid, bonded at the 2, 3, 5 and 6 carbon positions of ascorbic acid, leaving no free hydroxyl groups on the ascorbic acid ring. As with other ascorbic acid derivative chemicals, it is expected that the esters of ascorbic acid are cleaved by enzymes in the skin to release the ascorbic acid. Ascorbyl Tetraisopalmitate has been demonstrated to enhance intracellular accumulation of ascorbic acid in vitro in human skin fibroblasts, assumedly through esterolytic conversion to ascorbic acid. However, it is not known whether partial as well as full de-esterification occurs.

Now to address the question of whether Ascorbyl Tetraisopalmitate it cytotoxic to keratinocytes.?  Apparently because it has the word "palmitate" in it then everything that you find on Ascorbyl Palmitate applies to Ascorbyl Tetrasiopalmitate, or so the author thinks.

So is Ascorbyl Tetraisopalmitate cytotoxic to keratinocytes?  The answer is no.    Studies have reported it to be non-cytotoxic to keratinocytes in vitro up to a fairly high concentration (4,500 µM) [1].  Apparently she hasn't seen this study.

Vitamin C does not cause cancer and is a critical antioxidant in our defence system.  Please DO NOT believe the rubbish that is written online from sources that have no credibility to them at all.

About the Author

Jacine Greenwood is an internationally recognised educator who is known within the industry for her up to date knowledge and her ability to deliver training in an easy to understand method.

Jacine holds 6 Diplomas and a Bachelor of Nursing and her knowledge is well respected by her peers.  She is also a qualified Cosmetic Chemist.  With over 19 years experience in the industry and a background of cosmetic formulation, Jacine has an immense knowledge of current trends in research and new developments in the industry.

Jacine has been continually educating herself in all aspects of skin function and cosmetic chemistry for the past 21 years.  Jacine’s knowledge is current and has a vast knowledge of the active ingredients that are being released onto the market.

References:

Xiao et. al (2009) Cytoprotective Effects of the Lipoidic-Liquiform Pro-Vitamin C Tetra-Isopalmitoyl-Ascorbate (VC-IP) Against Ultraviolet-A Ray-Induced Injuries in Human Skin Cells Together with Collagen Retention, MMP Inhibition and p53 Gene Repression (January, 2009). Li Xiao, kentaro Kaneyasu, Yasukazu Saitoh, Yoichi Terashima, Yasunori Kowata and Nobuhiko Miwa. Journal of Cellular Biochemistry 106: 589-598.

Campos et. al (2012) Application of tetra-isopalmitoyl ascorbic acid in cosmetic formulations: Stability studies and in vivo efficacy (September, 2012) Patricia M.B.G Maia Campos, Mirela D. Gianeti, Flavio B. Camargo Jr., Lorena R. Gaspar. Faculty of Pharmaceutical Sciences of Ribeirdo Preto, University of Sao Paulo, Brazil. European Journal of Pharmaceutics and Biopharmaceutics 82:580-586.