Dispelling Sunscreen Myths

There has been a vast improvement in our understanding of the kind of damage that the sun can cause, both in academic circles and in the general public. Unfortunately, there are still many harmful myths which slow down the cause of sun protection and this article addresses some of these long-standing myths.

Aren't sunscreens mainly for people who beach or go camping?

Sunscreens are for everyone. Sunburns are what many people think of when they think of sunscreens, but it isn't the only danger. Sunburns are caused by UVB light which are dangerous, but to put it into perspective, only 5% of UVB light penetrates the ozone layer and reaches the earth. UVB is blocked out by glass, and is weaker during the winter. On the other hand, 95% of UVA light reaches the earth and can penetrate glass. This spectrum of light is constant year round, and causes premature skin aging, as well as increase the risk of skin cancer. Bottom line: Use broad spectrum sunscreens regularly year round to protect your skin.

Isn't vitamin D a necessary nutrient, only created by sun exposure?

Vitamin D is a necessary nutrient that is produced by the skin as it is exposed to the sun. It is thought that vitamin D synthesis is reduced by about 50% by use of sunscreen. The necessary amount of sun exposure to produce adequate vitamin D is very low, however. Exposure of 10 minutes a week is adequate to produce the required vitamin D, and further exposure causes vitamin D to degrade as fast as it is produced. Also, considering the amount of vitamin fortified dairy products, there are very few people that should be concerned about vitamin D deficiency.

I heard that some ingredients in sunscreens might actually cause cancer. Is that true?

There were some concerns about the potential for zinc oxide and titanium dioxide to produce free radicals when reacting to sunlight if it were to be absorbed deep into skin cells. Several studies have been conducted since, and the weight of evidence seems to point that the zinc oxide and titanium dioxide remains only on the surface of the skin. In general, the benefits of protection from UV light which is definitely carcinogenic, far outweighs the possible risk of using sunscreen.

Does SPF 100 mean that the sunscreen lasts 5 times longer than the SPF 20?

No. In theory, SPF is a measurement of how much longer the skin takes to burn compared to using no sunscreen. There are a few problems, however, and the FDA now takes the stance that SPF labels higher than 50 may be misleading.

  • SPF 30 products protect the skin from over 97% of UVB light. An SPF 100 may protect from 98 to 99 percent, a very marginal improvement. As these numbers may mislead some people into believing that they provide proportionately higher protection, the FDA has disallowed SPF claims higher than 50 for labelling in 2012.
  • SPF is tested under highly controlled laboratory conditions, which don't reflect real life conditions accurately. Even minor changes like a change in thickness of application, the presence of wind, water, or sweat can significantly change a product's SPF. Continual reapplication is more important than a higher SPF is in practice.
  • SPF is a measurement of protection from the UVB spectrum of light, but does not measure protection from UVA light.

High SPF products are not bad, but it's important not to rely too heavily on the big numbers. The important consideration when using sunscreens is using an adequate amount (1/4 to a 1/3 of a teaspoon just for the face), and to reapply every 2 hours. Finally, it is critical that you choose a sunscreen that provides broad spectrum protection, which means it protects the skin from both UVB and UVA light.

Is sunscreen the best way to protect the skin from sun damage?

Sunscreens are one of the most convenient ways to protect the skin while outdoors, but it certainly isn't the only form of sun protection. The most effective way to prevent sun exposure is, sun avoidance. While this isn't practical for most people, simply avoiding the sun from the hours of 11AM to 3PM can make a big difference. Clothing also has a natural sun protection factor. Long-sleeved shirts, sunglasses, and hats help provide protection from the sun. Sun protective clothing can provide protection similar to sunscreens.

Related video: