Here comes summer and sun – and hopefully sunscreens.
You might not have thought “What a medical breakthrough!” when you bought your current bottle of water-resistant SPF. And yes, using sunscreen daily is still a chore, especially when it’s the hard-to-rub-in kind. Nevertheless, the sunscreen in your hands is downright sophisticated and convenient compared to its earlier prototypes and represents a century of scientific experimentation and innovation.
Humans have been trying to protect their skin from the sun for thousands of years. These ancient sun-avoiders had no idea that repeated sun exposure could lead to cancer, but they did know that sunburns were painful! Many also lived in societies that viewed tanning as decidedly uncool. For example, to protect their skin from the sun ancient Egyptians applied a cream made of rice, lupin, and jasmine. This mixture may actually have offered some protection as rice contains UV absorbing chemicals. In addition, it likely prevented some of the worst symptoms of sunburns as both lupin and jasmine promote DNA repair. Undoubtedly, it smelled good.
In contrast, the ancient Greeks used olive oil which offers little or no protection. However, like lupin and jasmine, it may have helped skin cells recover to some degree after getting burned. Fortunately, the Greeks also used wide-brimmed hats and veils.
The most effective ancient sunscreen may have been the “burak” paste that early Philippine and Malaysian sailors made from water reeds, rice, and spices.
One of the first modern-day sunscreens came from an Australian named Milton Blake in the 1930s. By that time chemists were beginning to identify chemicals that could absorbed UV. Blake spent 12 years in his kitchen trying to mix these into a lotion that could easily be applied to the skin. Despite certain equipment limitations (his major tools were saucepans, room heaters, and hand scales), he did manage to develop a working prototype and eventually founded Hamilton Laboratories. Today Hamilton Labs is still making and selling sunscreens.
Around the same time that Blake was concocting in his kitchen, an Austrian chemistry student named Franz Greiter decided to go for a hike. Actually, he decided to climb a mountain and got a major sunburn as he traveled over its glaciers. Determined not to repeat this experience, he put his chemistry knowledge to work and developed a cream that would protect his face by absorbing both UVA and UVB light. The resulting product – named Gletschere Crème or Glacier Cream – was a success and was widely sold through Greiter’s company Piz Buin. Although Greiter’s glacial cream is generally regarded as the first effective sunscreen its SPF was only around 2!
(Incidentally, we can also thank Franz Greiter for the Sun Protection Factor (SPF) rating system. In the 1970’s he worked with two mathematician friends to quantifying the ability of different lotions to stop UV rays by creating a standard test and formula.)
The first widely use sunscreens was a sticky red pasted called Red Veterinary Petrolatum( RVP) which was used by US soldiers in the South Pacific during World War II. The product’s somewhat unflattering name comes from the fact that it’s a by-produced of the refining crude oil and deep red in color. By all accounts, the name was only matched by an equally unappealing texture – slick and sticky. Another drawback of the lotion was that it was tricky to apply – when it was rubbed into the skin too vigorously it amplified the sun’s damaging effects rather than minimizing them. However, during World War II it was still one of the most effective sunscreens available. In fact, it was so useful that it was kept top secret until after the war. Eventually, the inventor of RVP, airman Benjamin Green, sold the formulation to Coppertone who finally commercialized it in 1956 after considerable chemistry improvements – and some needed rebranding.
Today’s sunscreens are easier to apply and far more effective. Some remain effective on while we swim or sweat. These sunscreens work by combining chemicals that either absorb or reflect UV radiation. For example, inorganic compounds (such as zinc oxide and titanium dioxide) stay on top of the skin and scatter UV radiation. While organic compounds (such as oxybenzone and octinoxate) absorb the energy in UV light much like the natural skin pigment melanin. Using these sunscreens regularly reduces the risk of getting skin cancer and slows the process of photoaging. In one study daily application of SPF 15 reduced squamous cell carcinomas rates by 40% and melanomas rates by 50%!
Sunscreens have come a long way from their earliest versions. However, scientists continue to work to make these mixtures safer, more water-resistant, longer-lasting, broader spectrum, and better for the environment. If you want to learn more about the molecular biology behind this work, check out this article. Or if you’re looking for a hands-on investigation into the link between UV light and DNA damage check out our qPCR experiment.