Did you know that people who used sunscreen every day showed 24% less skin ageing over 4.5 years?
A question that seemed obvious
The idea that the sun contributes to skin aging is widespread. Yet in the early 1990s there was no solid evidence that using sunscreen regularly really slowed skin aging. The same was true for antioxidants taken through the diet.
Answering the question required a controlled study, many people and several years of follow-up. That is exactly what was done in Australia, a country with very high sun exposure.
How the study was done
The study took place in Nambour, Australia, and was published in 2013. It involved 903 adults under 55, chosen at random from a community register. Participants were randomly divided into four groups.
Some had to use a broad-spectrum sunscreen every day, while others could use it at their own discretion. In addition, half of the participants took a beta-carotene supplement and half a placebo. Aging was measured between 1992 and 1996 through changes in the microtopography of the skin, assessed by experts who did not know which group each person belonged to. The study was funded by a public Australian research body.
What was observed
In the daily sunscreen group, no increase in the signs of skin aging was detected after 4.5 years. From the beginning to the end of the study, skin aging was 24% lower than in the group that used sunscreen at their discretion.
Beta-carotene showed no overall effect on skin aging. The authors conclude that regular sunscreen use slows skin aging in healthy middle-aged men and women.
How to read the result
It is a randomized, long-term study with a large number of participants, which makes it one of the most cited references on the subject. The authors themselves point out some limits. Some data were missing and the study had limited power to detect moderate effects.
The message is one of the clearest that skin research can offer. Consistency counts, and sunscreen every day is a simple habit with solid evidence behind it. To choose the protection factor and the formula that best suit your skin and lifestyle, ask a dermatologist.
This article is for information only. It does not replace the advice of a doctor or dermatologist, whom you should consult with any question about your skin.