With 50 years of skin research behind him, Professor Hans Christian Wulf has seen what the sun can really do.
Here, he shares his best tips on how to protect yourself against harmful UV rays — including one clever trick that makes sunscreen last all day.
9 Out of 10 Cases Are Caused by the Sun
The vast majority of all skin cancer cases are triggered by sun exposure. It’s not random — and it’s often preventable.
Even Northern Countries Are at Risk
Despite living far from the equator, Danes are still highly exposed. More vacations in sunny regions and less clothing outdoors mean more skin is at risk than ever before.
The Sun Damages Your DNA
When UV rays hit your skin, they damage the DNA in your cells. Your body tries to repair it, but over time, damage builds up — and that’s when cancer can begin to form.
UVA and UVB Each Do Their Part
UVB rays are most strongly linked to skin cancer, while UVA rays penetrate deeper and damage your skin’s elasticity. The result? A double threat of cancer and wrinkles.
Clothing Beats Sunscreen — Every Time
The best defense isn’t lotion, but layers. Long sleeves, pants, and a wide-brimmed hat provide excellent protection, especially when the sun is at its strongest.
Sunscreen Works — But Only If You Use It Right
Sunscreen is only effective when applied correctly. Most people apply far too little, which reduces the actual SPF to just a fraction of what’s promised on the label.
Here’s How Much Sunscreen You Really Need
To get the labeled protection, you need 2 mg of sunscreen per square centimeter of skin. That’s roughly 40 ml for an average adult body — a full handful, not a dab.
One Trick Makes Sunscreen Last All Day
Apply your sunscreen twice in the morning, 15 minutes apart, before going outside. That double layer helps boost durability and reduces the need for reapplication.
Last Year’s Sunscreen? Maybe Still Good
If stored in a cool, dark place, your old sunscreen is probably fine. But if it sat in a hot car or on the beach, it may have degraded — not dangerous, but definitely less effective.
Don’t Forget the Back of Your Body
Many people forget to protect their backs, legs, and behind the ears. Unfortunately, that’s exactly where doctors often find early-stage skin cancer — so cover every angle.
This article is based on information from Illustreret Videnskab