Does sunscreen also protect against skin ageing?
Using broad-spectrum sunscreen daily demonstrably slows sun-induced skin ageing; anyone with concerns about chemical filters can switch to a mineral variant containing zinc oxide or titanium dioxide without any loss of protection.
Sunscreen demonstrably protects against sun-induced skin ageing, also known as photoaging: the wrinkles, pigmentation spots, rough skin texture and loss of elasticity that develop from years of exposure to UV radiation. The type of ageing differs by skin tone: people with lighter skin develop mainly wrinkles and loss of elasticity, while people with darker skin are more prone to pigmentation spots.
The strongest direct evidence comes from a randomised controlled trial in 903 Australian adults. Daily use of broad-spectrum sunscreen led to 24% less increase in skin ageing after 4.5 years compared with people who used sunscreen only occasionally. In the daily users, no measurable increase in ageing was observed at all.
The primary driver of photoaging is UVA radiation (wavelengths from 320 to 400 nm). UVA penetrates deeper into the skin than UVB, reaching the dermis, and causes damage through reactive oxygen radicals. Broad-spectrum sunscreen provides protection against both UVA and UVB. An important point to note: most common sunscreens on the American market provide insufficient coverage against long-wave UVA (above 370 nm) and visible light, both of which also contribute to ageing and pigmentation problems.
Visible light and infrared light may also contribute to skin ageing and pigmentation, but this has barely been studied in humans and the evidence remains limited. In addition, there are as yet no officially approved sun filters that specifically protect against visible light, meaning that standard sunscreen offers little help in this regard.
On the safety of sunscreen: chemical UV filters can be absorbed through the skin and have been detected at measurable levels in the blood, but clinical harm in humans has not been established to date. The scientific consensus still supports the use of sunscreen; further research into long-term safety is ongoing. Anyone with concerns about chemical filters can opt for mineral variants containing zinc oxide or titanium dioxide. Beta-carotene as a supplement has no protective effect against photoaging and is not recommended as an alternative based on the available data.
The key finding on daily sunscreen use comes from one randomised controlled trial (PMID 23732711, n=903). Other claims are based on review studies (PMID 34387824, 38772426, 39913224, 38924160, 40072791) and one study on plant-based antioxidants (PMID 33360043). No meta-analysis was used as a direct source.