The way sunscreen is applied determines its level of effectiveness

Researchers at King & # 39; s College London revealed that by applying sunscreen on the body they only get 40% of the expected protection because they are not enough applied.

Researchers at King's College London (UK) conducted a study that reveals that by applying sunscreen on any surface of the body, it only reaches that 40% of the expected protection because it does not apply enough, set by specialists in 2 milligrams per square centimeter

This research, published in the journal 'Acta Dermato-Vénérologie & # 39; 39, is the first experiment of its kind to evaluate the damage to the skin's DNA after reducing the thickness of the application of sunscreen below the amount recommended above.

The results showed that sun protection with a protection factor of 50, applied as usual, provides at best 40% of the expected protection. That's why researchers at King's College London are asking consumers to use a much higher filter than they think they need to make sure they're doing it. are protected against skin damage caused by the sun.

As part of the investigation, scientists divided a cohort of 16 white-skinned volunteers into two groups of eight (three women and five men in each group). One group received a single exposure to ultraviolet light, to simulate sunlight, in areas treated with high-protection sunscreen. The amount of application was variable, from 0.75 milligrams of thickness, 1.3 and finally 2 milligrams per square centimeter

The other group received exposures in five consecutive days, for imitate what can happen on vacation. The amount of exposure to ultraviolet rays has varied over the course of the experiment, in order to mimic conditions in holiday destinations, like Tenerife, Florida or Brazil.

Skin biopsies exposed to ultraviolet light showed that, for the group that was repeatedly exposed, considerable damage to DNA was found in areas that did not receive sunscreen, even if the radiation dose was very low. This damage was reduced when the sunscreen was applied to a thickness of 0.75 milligrams and was significantly reduced when 2 milligrams per square centimeter were applied, even with much higher ultraviolet doses. .

In this same line, five days exposure to high doses of ultraviolet rays with sunscreen of the recommended amount showed significantly less damage than exposure to a low dose for a day without sunscreen in all samples.

"There is no doubt that protectors Solar cells provide important protection against cancer that causes the impact of the sun's ultraviolet rays, however, what this research shows is that it is The use of sunscreen plays an important role in determining its effectiveness, "he explains.Antony Young, lead author of the researcher and professor at King's College London.