By Dr. Lydia Thurton
June 4th, 2014 Edition
While there is a lot of press about breast, colon and prostate cancers, it is actually skin cancer that is the most common. While lighter skin tones are more susceptible to the sun’s ultraviolet radiation people of all ethnicities and races need to be mindful. Skin cancers often go undetected in people of color, especially those with darker pigmentation, and are therefore more deadly. We all need sunscreen if we are going to be spending extended time in direct sunlight.
Sun protection factor, otherwise known as SPF is labeled on every bottle of sunscreen. The idea is that an SPF of 15 would allow you to stay in the sun, without getting burned, 15 times longer than you would with no sunscreen applied.
The sun’s ultraviolet rays are called UVA and UVB. UVB will cause burns, UVA does not, but can still trigger cancerous changes in the skin. A good sunscreen blocks both UVA and UVB.
An SPF 15 blocks 93% of the sun’s rays, while an SPF of 30 blocks 97% of the sun’s rays and an SPF of 50 blocks 98% of the sun’s rays. As you can see there is not a large difference in terms of protection, despite the actual SPF numbers getting significantly higher. There are no sunscreens that block 100% of the sun’s ultraviolet radiation.
In fact, Health Canada is considering banning sunscreens that claim an SPF over 50 because they lead people to believe they are safe in the sun for a long period of time, when they are not.
Sunscreen ingredients have been very controversial in the last few years. The two factors to consider are the physical effects of chemical ingredients and how much of the chemical absorbed through the skin when it is applied topically. Oxybenzone is an ingredient commonly found in drug store brands. It is readily absorbed through the skin and has been shown to be a hormone disruptor. It is also found in baby sunscreens. Do not assume a child sunscreen is free of harmful chemicals. Avoid products with this ingredient.
Retinyl palmitate, a form of vitamin A, is added to some sunscreens to reduce the signs of aging skin. It has been shown to actually increase the susceptibility of the skin to sunburns, which in turn can lead to cancerous changes. Avoid sunscreens with this unnecessary ingredient.
My favorite sunscreens have titanium dioxide or zinc oxide. Both are very safe ingredients that provide broad spectrum protection. Avobenzone is another ingredient that does a great job of blocking UVA and is not absorbed into the skin. Safe sunscreens are becoming widely available as consumers become more savvy shoppers and read ingredients. Remember, your skin is your largest organ, what you put on your skin can be absorbed. Shop smart!