There are several ways you can get a natural tan. The most obvious is from the sun. Light from the sun reaches the earth in three different forms: visible light, infrared light, and ultraviolet light. The last type, ultraviolet light, is classified into three separate categories:
* UVA or black light, which causes tanning.
* UVB, which typically causes damage in the form of sunburn.
* UVC, which doesn’t affect us because it’s filtered out by the atmosphere before it can get to our skin.
The problems we associate with sun exposure, such as premature aging, skin cancer, sun spots, etc. are primarily caused by harmful UVB rays. Research suggests UVA might have a hand in these things as well. Most of the sun’s UV radiation at sea level is UVA rays.
UVA can be reflected, as well. Snow actually reflects roughly 90% of UV light, which is why you can get severe sun burns while skiing or snow boarding. Sand reflects up to 20% of UVB too, so at the beach, you’re getting more UV exposure than you would be getting if you were sitting in your backyard. Water also reflects UV light, although it doesn’t prevent it from penetrating the surface of the water. You can still get burned while swimming. Some surfaces can absorb these rays rather than reflect them. Certain types of glass do this, and our own melanin in our skin absorbs UV light to some degree.
Ultraviolet light in the sun stimulates the production of melanin. This pigment protects cells from damage by absorbing as much UV radiation as it can. Imagine you put a sponge on top of a piece of paper and slowly dropped beads of water onto it. The sponge would soak the water up before it can ruin the paper. That’s sort of what your melanin does to UV rays. It can become saturated, though. Eventually if you keep dropping water on it, the paper will be ruined.
It’s this protective melanin in your skin which gets darker and creates what we call a tan. Caucasians typically have the least amount of melanin in their skin on a day-to-day basis, but in many other races, there is a continuous melanin production, which causes the skin to remain pigmented and also offers more protection against UV rays.
It’s important to note that all UV rays are potentially dangerous. They can cause deep damage to your cells, which results in painful sunburn at best and fatal skin cancer at worst. It’s important to protect yourself from skin damage by wearing sunscreen when you’re outside. Avoiding direct sunlight is the best way to protect yourself. This really ruins your chance at a tan, though.
There is one more way that you can get naturally darker skin, however. That’s through DHA. DHA is an organic compound naturally found in your own body that creates a chemical reaction within the amino acids in the outermost layer of your skin when applied directly to the exterior of your body. This reaction does not involve the underlying skin pigmentation, nor does it require exposure to ultraviolet light to initiate the change in color. It is similar to the maillard reaction which occurs in food. It’s a natural, temporary color that looks just like a tan that occurs from melanin. The active ingredient in airbrush tanning is DHA. The color produced in an airbrush tan typically lasts 7-10 days, but it is much safer than roasting yourself in the sun or using a tanning bed.