Sunscreens are chemical agents that help protect our skin from the harmful effects of ultraviolet radiation.
Ultraviolet radiation comes in three basic forms: Ultraviolet A, B and C (UVA, UVB and UVC). UVC is blocked by the ozone layer, so we really are talking about UVA and UVB protection with sunscreens. Sunscreens are not sunblocks! I know of no sunscreen that blocks 100 percent of all ultraviolet A and B. Ultraviolet B is also known as the “burning rays.” Most auto glass and windows actually block these rays. SPF refers to the protection from UVB, not UVA. UVA is thought to penetrate right through glass and thus significant exposure may occur while driving. UVA also penetrates the skin more deeply and is thought to have a greater contribution to the formation of skin cancer than UVB. UVA also has a large impact on the aging process called “photoaging,” represented by the leather-like appearance and sagging of chronically sun exposed skin.
SPF and what it means
SPF translates to “Sun Protection Factor” and refers to UVB alone. An SPF of 15 blocks approximately 93 percent of the UVB. An SPF of 30 is not twice as good! It blocks 97 percent! An SPF of 45 is about 98 percent. These are not big differences, but in some people it may make a significant difference over time. If you take 10 minutes to get “red” or burned without sunscreen, an SPF of 15 applied properly would take 15 times longer or 150 minutes to get the same amount of redness or burn. When it comes to UVA protection, look for a broad spectrum sunscreen. The level of UVA protection is difficult to quantify at this point because there is no SPF-like rating yet for UVA in the United States. Australia, Japan and Great Britain have systems such as PPD which means Persistent Pigment Darkening. Until we have a system in this country to grade the UVA protection, I would ask your dermatologist for a recommendation or visit the Skin Cancer Foundation website to browse the list of accepted sunscreens.
Do sunscreens cause cancer?
There have been some news reports recently by the Environmental Working Group questioning the cancer causing potential of the Vitamin A (Retinyl Palmitate) found in many sunscreens. They based their report on an unpublished, 10-year-old study in mice. I have looked extensively and have yet to find this information published in any peer-reviewed journal of dermatology. Further, most sunscreens have trace amounts of this Vitamin A. Many experts feel that Vitamin A is actually an antioxidant that may provide additional protection form harmful UV rays. In the very least, this is at best a controversial report and warrants further investigation. At this point, the data supports the use of sunscreens with the Vitamin A derivative.
Does oxybenzone cause cancer?
Oxybenzone is excellent at UVA protection. It is a synthetic estrogen and there has been studies in rats. In rats, Oxybenzone is thought to interfere with the balance of the body’s hormones and lead to free radical formation. The theory is that there is an increased risk of skin cancer, namely melanoma. The truth is that Oxybenzone has been available for 20 plus years and has been exhaustively studied. The Skin Cancer Foundation’s photobiology committee has reviewed Oxybenzone and is not concerned with these accusations of Oxybenzone and rats.
How do I get Vitamin D if I use sunscreens?
It is true that Vitamin D is converted from an inactive form to an active form from UVB exposure. The problem is to sort out the risk of the UVB exposure and the benefit of the Vitamin D. There is little argument that we all need Vitamin D, especially for a strong skeletal system. The recommendations are that we obtain our Vitamin D from our diet, not UVB exposure. The amount of Vitamin D recommended depends on your age and sex. It is important to check with your doctor about your Vitamin D level and what they recommend for your daily intake. Again, Vitamin D is important, but getting it from our diet and supplementation is safer than through sun exposure.
What can I use to ensure adequate UVA and UVB coverage?
La Roche Posay has an excellent line of products with Mexoryl and Cell-Ox shield. I have been very impressed with the amount of protection that they provide. They also have a very nice cosmetic feel to them. This particular line was approved in Europe before the USA and therefore has been graded for UVA protection in Europe. Using the La Roche Posay line is one way to ensure you are adequate UVA and UVB protected. I also am a big fan of sun protective clothing and hats. There are many websites and stores that carry wonderful, trendy looking sun protective clothing. Using both sun protective clothing and hats, as well as a broad spectrum sunscreen has additive benefits. This is the approach I take in my family using swimshirts, hats and the new La Roche Posay line of sunscreens.
Skin cancer is the most common form of cancer in the United States. One in five Americans will develop skin cancer in their lifetime. Malignant melanoma is a deadly form of skin cancer on the rise and sun exposure has been linked to it as well as basal cell carcinoma and squamous cell carcinoma. It is prudent to become educated on sun protection and sun avoidance. It is also prudent to get routine skin exams from a qualified health care professional. “An ounce of prevention is worth a pound of cure.”
• Avoid sun during the peak hours. You know the sun is strong when your shadow is shorter than you – usually between 10 a.m. and 4 p.m.
• Wear a broad spectrum sunscreen with an SPF of 15 or greater every day. The Skin Cancer Foundation website has a list of approved sunscreens (skincancer.org).
• Use sun protective clothing in addition to sunscreens.
• Use at least one ounce of an approved sunscreen, apply 30 minutes before going out in the sun. Reapply every two hours or more frequently if sweating or swimming.
• Avoid tanning beds! They have been shown to increase the risk of malignant melanoma – the deadliest form of skin cancer.
• Get skin exams annually by a qualified expert in skin cancer. The ABCDEs of moles and melanoma is a good guideline to use to monitor your moles. This can be found on the following websites AAD.org, AOCD.org and skincancer.org.