The method in which we apply sunscreen may actually be completely wrong! It leaves our skin with less than half the expected protection it otherwise requires.
A recently concluded study conducted by researchers from King’s College London, revealed that when sunscreen is applied in a typical way, it provides only 40% of the sun protection factor (SPF). For example, sunscreen with a sun protection factor (SPF) of 50, applied in a typical way, would at best provide 40% of what is expected from it.The study found that protection of skin was only significant when sunscreen was applied at a thickness between 1.3 and 2.0 milligrams per centimetre square, whereas most people only apply a layer of 0.75.
To investigate how protective sunscreen is, the researchers measured the amount of DNA damage in the skin of 16 volunteers who wore different thicknesses of sunscreen when they were exposed to UV light.
The study participants were split into two groups of eight: one group received just a single dose of UV radiation to mimic sunlight exposure, and the second group received several doses over a period of five days to mimic continuous holiday exposure.
Volunteers received their UV radiation doses within 15 minutes of having their sunscreen applied, and skin biopsies were taken immediately after the UV exposure. The sunscreen tested in the study was compliant with EU regulations.
Skin biopsies revealed that those in the “holiday group” who wore higher sunscreen, experienced significantly more protection from the Sun, in comparison to the ones who applied it thinly.
“There is no dispute that sunscreen provides important protection against the cancer-causing impact of the sun’s ultraviolet rays,” said Young. “However, what this research shows is that the way sunscreen is applied plays an important role in determining how effective it is.” He added, “Given that most people don’t use sunscreens as tested by manufacturers, it’s better for people to use a much higher SPF than they think is necessary.”
Nina Goad of the British Association of Dermatologists said, “It also shows why we shouldn’t rely on sunscreen alone for sun protection, but we should also use clothing and shade. An extra consideration is that when we apply sunscreen, we are prone to missing patches of skin, as well as applying it too thinly.”
The research concluded that it is important to choose an SPF of 30 and more. Even though in theory SPF of 15 should be sufficient, but in real conditions, a higher SPF protection was inevitable.