What you should know about sun cream ingredients.
Summer is back again and so is the yearly dilemma: how can I enjoy the nice weather and protect my skin at the same time? With such a plethora of sunscreens which one should I use?
We can distinguish two types of UV filters. Sunscreen active ingredients can be classified as either physical UV filters or chemical filters. The former creates a barrier that scatters the rays and the latter absorbs the UV light. Doctors and scientists have always been debating on which of the two is the safest for both humans and the environment: in fact, each system has its advantages and side effects. Let’s see in details what they are.
While physical blockers are generally inorganic compounds, like titanium dioxide and zinc oxide, chemical blockers are organic molecules with long and weird names like avobenzone or octinoxate. Nevertheless, chemical blockers have frequently been accused to penetrate the skin and interfere with the hormone system causing serious diseases, like cancer. Also, physical filters cause less adverse reactions, like blisters, itching, rash, irritations, and they generally have a higher sun protection factor, the famous SFP. But, they will make you look paler when you apply them on your body.
This last problem can be solved by using nanoparticles as physical filters: the final product will be less opaque and the effectiveness increased. Problem solved, right? We should use physical UV blockers, shouldn’t we?
Apparently not; physical filters can increase the skin absorption of pesticides, causing adverse effects. In addition, nanoparticles are, just like the chemical filters, more reactive and they can generate free radicals.
Last remark, some scientists have hypothesized that sunscreen may actually promote skin diseases by inhibiting the skin inflammation. Normally mechanisms would alert us to stop sunbathing. Sunscreen obstructs this mechanism and makes us prolong our sun (and UV) exposure.
The choice is now up to you: which protection will you use? Chemical filters, physical filters, or maybe no holiday by the seaside?
Brand RM, Pike J, Wilson RM, & Charron AR (2003). Sunscreens containing physical UV blockers can increase transdermal absorption of pesticides. Toxicology and industrial health, 19 (1), 9-16 PMID: 15462532
Schlumpf M, Schmid P, Durrer S, Conscience M, Maerkel K, Henseler M, Gruetter M, Herzog I, Reolon S, Ceccatelli R, Faass O, Stutz E, Jarry H, Wuttke W, & Lichtensteiger W (2004). Endocrine activity and developmental toxicity of cosmetic UV filters–an update. Toxicology, 205 (1-2), 113-22 PMID: 15458796
Serpone, N., Dondi, D., & Albini, A. (2007). Inorganic and organic UV filters: Their role and efficacy in sunscreens and suncare products Inorganica Chimica Acta, 360 (3), 794-802 DOI: 10.1016/j.ica.2005.12.057
sunscreen, summer, Sun, UV light, physical UV filters, chemical filters, sun cream ingredients, skin, SFP, inflammation, nanoparticles, free radicals, skin diseases