Sunscreens are regarded as one of the most effective tools to protect skin from the harmful effects of solar radiation. These rays cause various types of cellular damage, including DNA mutations, alterations to structural proteins such as collagen and elastin, and skin inflammation. Over time, these changes accelerate the skin aging, and notably increase the risk of skin cancer. In response, public health agencies recommend protecting against sun exposure by avoiding extended direct exposure, especially between 11 a.m. and 4 p.m., wearing long clothing, and using a sunscreen with a high SPF. Despite these benefits, some concerns remain, and sunscreens are sometimes suspected of becoming carcinogenic over time.
Current scientific data do not support that sunscreen use increases skin cancer risk; they indicate the opposite.
A 2014 meta-analysis pooled results from 21 studies involving 7,150 malignant melanoma cases. Using regression, researchers demonstrated that sunscreen use did not increase melanoma risk, even with long-term use. In reality, studies show a significant protective effect of sunscreens against skin cancers. One robust piece of evidence comes from a randomized controlled trial in Australia. Over 4.5 years, 1,621 adults were followed to assess the impact of daily use of a broad-spectrum SPF 15+ sunscreen.
In this protocol, volunteers were divided into two groups: one applied sunscreen daily, while the other used it at their discretion, or not at all for some participants. At the end of the trial, the daily use group showed a 40% reduction in squamous cell carcinoma incidence compared with the control group. The protective effect persisted after the intervention. Eight years after the protocol ended, the daily use group still showed a 40% reduction in squamous cell carcinoma incidence. This sustained effect reflects that more participants in this group maintained regular sunscreen use after the trial.
Far from increasing the risk of skin cancer, the regular and rigorous use of sunscreen is a effective prevention tool.