UV Protection

Ultraviolet radiation causes direct DNA photoproducts and oxidative damage that drive photoageing and skin cancer. Topical sunscreen, protective clothing and shade remain the only interventions with robust preventive evidence. Oral photoprotectants raise the minimal erythema dose modestly — typically equivalent to an SPF of around 1.5 to 3 — which is meaningful only as a supplement to, never a replacement for, topical protection. Beta-carotene is a cautionary case: it modestly reduces sunburn but increased lung cancer incidence in smokers in the ATBC and CARET trials, so it should not be recommended broadly.

1) Use broad-spectrum SPF 30+ sunscreen daily and reapply every two hours outdoors — the intervention with actual skin cancer prevention data. 2) Wear protective clothing, a wide-brimmed hat and UV-blocking sunglasses, which outperform any oral agent. 3) Seek shade between 10am and 4pm when UV index is highest. 4) Never use sunbeds, classified as a group 1 human carcinogen. 5) Treat oral photoprotectants as an adjunct that adds a small internal buffer, not a licence to extend exposure. 6) Check the UV index rather than judging by temperature or cloud cover. 7) Get regular skin checks if you are high risk or have a history of significant sun exposure. 8) Avoid high-dose beta-carotene entirely if you smoke, given the increased lung cancer risk in trials.

• •Daily broad-spectrum SPF 30+
• •Protective clothing and hats
• •Shade during peak UV hours
• •Avoiding sunbeds
• •Checking the UV index
• •Regular skin checks