Self-Tanners and Potential Aging Effects
Self-tanning agents work by producing an artificial “tanning” process from the reaction between the proteins on the surface of skin and the reducing sugars (such as dihydroxyacetone (DHA)) of the self-tanner. DHA has been known for awhile to be a color additive, but it was only until recently that DHA formulations can act gradually and emulate a natural bronze-y tan without appearing too orange on most skintones. Their sweeping popularity is a testament to them being the obvious “no-brainer” choice for a substitute “tan” when it is now commonly known that real tans achieved by UVB and UVA exposure lead to skin wrinkling, sagging, and discoloration.
But what if self-tanners also age skin? How would that be possible? A keen eye and a previous reader of my “Glycation” articles would pick up on the word sugar and raise an eyebrow.
When food undergoes heat treatment, the Maillard reaction is promoted (see: Cooking Methods (And Precooked foods) Overlooked in Diabetes (Glycation: Part I)), which involves reducing sugars acting non-enzymatically with amino acids in protein, lipids, or DNA. While I wrote about how ingesting AGEs (advanced glycation end-products) aggravates diabetes and its complications, exogenous AGEs (i.e., ingested AGEs) also pose many potential problems for non-diabetics such as adverse metabolic changes and can accelerate the development of various degenerative conditions such as atherosclerosis, cataracts, Alzheimer’s disease, vascular dementia, sarcopenia, rheumatoid arthritis, Parkinson’s disease, end-stage renal disease, and several others. (1)
So, how does this relate at all to self-tanners? As self-tanners make contact with the skin, the Maillard reaction forms with the reducing sugar (DHA) and the amino acids on the skin. The Maillard reaction is the first step in the formation of irreversible advanced glycation end-products (AGEs), and the Maillard reaction itself already generates some free radicals that parallel with the browning process. (4) With natural sun-tanning, many AGEs are rapidly produced, eventually leading to skin stiffness and loss of elasticity. (2-3) It might be thought that Maillard reaction products on the skin due to self-tanner application may accentuate the glycation reaction to sunlight, and so far research supports this theory.
One study set out to quantity the protection—or lack thereof—of UV-induced free radicals on self-tanner-treated skin compared to untreated skin. This study found startling results:
The skin treated with DHA produced over 180% more free radicals than untreated skin after UV exposure. (5) Erythrulose, another reducing sugar found in some self-tanning agents, also generated more free radicals on UV-exposed skin than on untreated skin, albeit a bit less than with DHA. (Ibid) The amount of free radicals produced increases with the concentration of DHA; so, in other words, those who re-apply self-tanners daily to build up a dark tan or those who use dark formulations are most at risk. Simply put: more browning equates to more Maillard reactions. The amplification of oxidative stress induced by UV exposure on skin treated with these reducing sugars is explained by the progression of the glycation process (pre-existing Maillard reaction products on skin with self-tanner) by UV rays (mainly UVA rays). More specifically, Maillard products become Amadori products, which are intermediate glycation products that activate free radicals (i.e., oxidative stress) during UV-light exposure.
In short, it can be said that exposing the skin to UV light while using self-tanners accelerates photoaging. For those who wish to have a darker skin tone without the damaging effects on skin, there are fortunately several mitigation strategies that are discussed below.
Mitigating Pro-aging with Self-Tanners
If one lives as a vampire, the enhancement of photoaging would not be a concern, but those who plan to enjoy the sunshine while being “tan”, or even go out in daylight for that matter, should take simple precautions to avoid harmful skin aging effects with self-tanners.
Really, the best option for those who simply want a “glow” would to be apply bronzer instead or some form of pressed powder on the face after sunscreen application. With this method, one can go about 2 shades darker without looking artificial. This way, one can enjoy the benefits are subtle darkening without inheriting the risk of greater oxidative stress with self-tanners.
Then again, for those who are looking for a more lasting and dramatic tanning effect, self-tanners are inevitably sought after. This is OK, as long as the following easy-to-follow risk mitigation strategies are adopted.
When using self-tanners, it is imperative to invest in a broad spectrum UVB/UVA blocker (most sunscreens are not suited to this need) such as Uvinul A Plus B, Mexoryl SX (ecamsule), or physical sunscreens zinc oxide and titanium dioxide. It is most important that the chosen brand of sunscreen has sufficient UVA-blocking capabilities as these are the rays that are overwhelmingly responsible for the dramatic boost in free radical production. While UVA filters significantly block the UV-induced free radicals, waiting until after 4 hours post-application to go out will result in even fewer free radicals generated by UV light as the Maillard reaction would be fully complete by this time and less reactive to induce oxidative stress with sunlight. (4) For that reason, it’s best to apply self-tanner at nighttime. Applying a strong UVA filter after self-tanning would not interfere with the tanning capabilities of the product.
To further decrease free radical production by the Maillard reaction itself that occurs without UV exposure, users may consider applying a homemade vitamin C serum or some antioxidant mixture serum roughly 30 minutes before administrating self-tanner to neutralize upcoming radical production.
- Luevano-Contreras C, Chapman-Novakofski K. Dietary Advanced Glycation End Products and Aging. Nutrients. 2010;2(12):1247-1265. doi:10.3390/nu2121247.
- Lee EJ, Kim JY, Oh SH. Advanced glycation end products (AGEs) promote melanogenesis through receptor for AGEs. Scientific Reports. 2016;6:27848. doi:10.1038/srep27848.
- Crisan M, Taulescu M, Crisan D,et al. Expression of advanced glycation end-products on sun-exposed and non-exposed cutaneous sites during the ageing process in humans. PloS one. 2013 Oct 7;8(10):e75003.
- Jung K, Champ S, Flosser-Muller H, et al. The Vital Consequences of Choosing the Right UV-filter for the Prevention of Free Radical Boosting in UV-irradiated Skin after the Application of Self Tanning Creams. SÖFW Journal. 2008;134(7):32.
- Jung K, Seifert M, Herrling T, et al. UV-generated free radicals (FR) in skin: their prevention by sunscreens and their induction by self-tanning agents. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 2008 May 31;69(5):1423-8.