Beware of broken promises of sunscreen and endocrine disruptors

Crèmes solaires : des promesses non tenues ?

A l’université de Nantes, deux chercheuses passent chaque année au crible différentes références de crèmes solaires. Laurence Coiffard et Céline Couteau, toutes deux docteures en pharmacie, alertent sur des crèmes protectrices indice 50 et 50+ qui ne tiennent pas leurs promesses.

Before packing your bags, choose skin cancers, carcinomas and melanomas, especially in the case of unprotected exposure in childhood.

How to choose the right sunscreen ? For fair, very fair, or sensitive skin, SPF 50 or 50+ is recommended by dermatologists. As a reminder, no cream offers complete protection against the sun's rays and this term must no longer be used by manufacturers since 2007.

In-vivo tests that overestimate the SPF index ?

Laurence Coiffard and Céline Couteau, both doctors of pharmacy at the University of Nantes (Loire-Atlantique), published on their site "Looking at cosmetics" during June the results of tests carried out for 26 references displaying values ​​of SPF 50 or 50 +. "We test them in vitro using a method which was the subject of a scientific publication in the International Journal of Pharmaceuticals. We use plastic plates that simulate the skin surface where we apply the product we are testing. UV radiation is then sent there and we measure how the applied product blocks the radiation, explains Laurence Coiffard.

Why did they question the in vivo tests carried out by the cosmetics industry ? "They are significantly less reliable and systematically overestimate the indices because substances with anti-inflammatory activity are present", points out the researcher. The presence of these products with anti-inflammatory properties reduces skin reactions linked to exposure to the sun, and therefore increases the SPF in vivo, but does not further protect the skin from the occurrence of cancer, according to the researcher.

Result ? Of the 26 references tested, "lthe differences observed between the measurements carried out in vitro by us and the values ​​displayed on the packaging vary from 6 units in the best cases to 38 units in the worst case. And this even for sun creams which are particularly aimed at children.

Avoid mineral filters…

Difficult for the consumer to make the right choice in these conditions. "For this summer, we will place on our podium of the best products, the following winning trio: A-Derma, Bariésun and Bioderma, effective and alcohol-free formulas!", indicate the two experts on their website.

Laurence Coiffard also recommends avoiding sunscreens with mineral filters (zinc oxide, titanium oxide), none of which can achieve an SPF 50. "The differences observed between our measurements and the values ​​displayed vary from 22 units in the best case to 40 units in the worst case", write the researchers. This was recently confirmed by UFC-Que Choisir in its comparative trials of 50 and 50 creams+. "We know that it is technically complicated to achieve an SFP 50+ with these physical barriers ", wrote the Union des consommateurs concerning the mineral solar.

… and products containing alcohol

Laurence Coiffard also advises choosing an alcohol-free cream. "The problem of alcohol, among others, is that ;it promotes the penetration of filters through the skin. Which explains why we currently find filters in blood, urine, breast milk, seminal fluid… Alcohol is one of those ingredients that promote this passage, specifies the specialist.

Beyond these disappointing tests, Laurence Coiffard considers that the controls are insufficient and warns of "a health scandal which is only growing and that we have been denouncing for years. Each year in France, between 141,200 and 243,500 skin cancers are diagnosed in France, 85% of which are linked to excessive exposure to UV radiation.

Note: on the side of UFC-Que Choisir which tests the products according to the hybrid method, which combines in vivo tests and in vitro, it is the protective sunscreen 50 from the Respire brand that protects the most effectively.