Fake tan (dihydroxyacetone) the killer in the next door!!!

What is a fake tan, which is scientifically known as dihydroxyacetone? In one of my articles I described how fake tan could be synthesized from glucose, you can check it here FAKE TAN, but DHA applied in self-tanner are manufactured from the fermentation of glycerine in the presence of Acetobacter suboxydans. Dihydroxyacetone is a cosmetic product some people use to tan the appearance of their skin. When fake tan is applied on the body, it interacts with the amino acids thereby forming a permanent color on the skin. However, the color wears off within a week since the skin continuously shades off. 

How the tanning (brown effect of dihydroxyacetone) was discovered?

In the research published by C and EN states that the brown effect of DHA was found at the University of Cincinnati Children’s Hospital when Eva Wittgenstein was investigating the result of dihydroxyacetone large doses in children who were suffering from glycogen storage disease. It was reported that these children were ingesting approximately one kilogram of DHA according to their body weight.  At some points, these kids could spit some amount of concentrated dihydroxyacetone, and some quantity of DHA splashed on their skin.  After a few hours the kids’ skin where the amount DHA had been wiped off, turned brown. 

Reaction of dihydroxyacetone with amino acids

The reaction that takes place between amino acids and dihydroxyacetone is known as the Millard reaction. Louis Camille Millard discovered this reaction in 1912, where he observed that amino acids reacted with dihydroxyacetone to form golden brown or brown compounds.  The Millard reaction is what responsible for the browning effect that takes place during the processing and storage of most foods, for example,  the golden brown color of the beer. In this reaction, there is presence of hydroxyl groups (two OH^-) from DHA and amino group and a carboxylic group (-COO^-) from amino acids. Therefore, the possible chemical reaction between dihydroxyacetone and amino acid is esterification. According to studies, the reaction takes place under acidic conditions. In the initial step of the reaction, the  DHA  reacts with amino acids of the skin under acidic conditions, the amino is converted to ammonium salts while the carboxylic group does not dissociate to form a stable ammonium salt. However, this is later neutralized by a base to form an unstable compound, as shown in the reaction below (reaction of lysine with dihydroxyacetone).  

Lysine + Dihydroxyacetone (DHA) = Stable ammonium salt (brown) = Unstable compound (brown)

The image below shows how the reactions occur, where the methanol and R-C ((NH₃) (CO₂^-) represents DHA and lysine respectively.

Studies show that amino acids in the epidermal proteins are arginine, lysine, histidine and glycine, though, the contents of Arg, Lys and His are more pronounced. According to Eva’s research, arginine was more reactive than other amino acids, and it formed a brown compound within thirty minutes.  

Dangers of dihydroxyacetone

Early researchers indicate that DHA cannot penetrate past stratum corneum. Hence, DNA is safe on the body. In contrary to this perception, some scientists associate DHA with genetic mutations. According to Dr. Ray Panettieri , a lung specialist and toxicologist at the Pennsylvania University told ABC NEWS that the dihydroxyacetone compounds in some cells could induce the growth of cancer and malignancies. Dr. Lynn Goldman at the Washington University noted that the DHA might react with the living cells hence leading to DNA change (mutations). A team of five doctors and Dr. Panettieri reviewed ten DHA scientific studies and noted the dangers of spray tanning to human. The FDA authorized the use of dihydroxyacetone in 1970, however, as a component in the tanning creams and lotions. Doctors say when someone inhales DHA. It is capable of causing lung cancer. Therefore, there is a need for more research on the dangers associated with the dihydoxyacetone (Fake tan) to disapprove any doubt.