A Fishy Source for Sunscreen

Have you ever seen a sunburned fish?

When you visit the beach, you can smear greasy sunscreen all over your body to protect your skin from the sun’s harmful ultraviolet rays. (Then the ocean water washes the lotion off and you get burned anyway, but that’s another story.) The poor little zebrafish, which lives in shallow water, doesn’t have that option.

All day it’s exposed to ultraviolet rays. If it gets burned, it doesn’t have a bottle of aloe vera lotion waiting in the hotel room, ready to soothe the pain.

• Sunscreen Patterns

But God didn’t forget the zebrafish. He gave it special protection that human beings may soon be using. More on that later. First, why do living things need protection from the sun’s life-giving energy, anyway?

We all enjoy the light and the tan, but energy from the sun comes in different intensities at the same time: radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays. The last three are the most penetrating and energetic—meaning they’re dangerous.

The earth’s atmosphere protects us from their most deadly effects, but some ultraviolet sunlight (UV) still reaches the earth’s surface in two varieties (conveniently labeled A and B). UVA penetrates more deeply into the skin and can cause wrinkling and aging. UVB reddens the surface and causes sunburn. Both can cause skin cancer. Sunscreen and sunblock lotions provide a healthy barrier against these UV rays, but how do they work?

If you read the label on a bottle of sunscreen, you’ll see an impressive array of chemicals. Some products contain the inorganic compounds zinc oxide and titanium oxide, which reflect UV directly away from the skin. Most also include organic molecules, which absorb the UV. But commercial skin applications aren’t perfect. They can be greasy, they often wash off, and the chemicals in them sometimes cause allergic reactions or irritate the skin.

That’s where the zebrafish comes in. It makes its own sunscreen internally, an organic compound called gadusol (C₈H₁₂O₆) that efficiently filters ultraviolet light. Researchers are studying ways to make synthetic gadusol in large enough quantities for commercial production. Their research may even lead to a sunscreen pill—no muss, no fuss, and it wouldn’t wash off in the ocean.

The zebrafish isn’t the only animal that generates its own sun protection. Many fish, amphibians, reptiles, and birds produce their own forms of sunscreen. For example, some reef-dwelling fish produce a mucus with amino acids that readily absorb UV rays. Scientists are working on a natural sunscreen by combining these amino acids with a chemical called chitosan, derived from shrimp. The result will be biodegradable and skin-friendly (and hopefully nothing like mucus).

The new generation of nature-inspired sunscreens may do more than protect our skin. Ultraviolet solar radiation fades paint and degrades plastics. Biodegradable sun protection may also prolong the life of exterior paint and house siding.

The Creator has imbedded countless useful ideas in nature for our benefit, from Velcro to sunscreen. Each displays intelligent planning and provision for God’s children. When we care for and study creation, we obey God’s command to subdue the earth (Genesis 1:28). Along the way, we find practical benefits with new products and solutions to daily problems.