Now that summer is here, you may be wondering what you need to know about the sun’s rays and how to choose an appropriate sunscreen!
The Truth about High SPF
True or false: An SPF 100 sunscreen allows you to stay outside for double the time than a SPF 50 sunscreen. False - the SPF can fool us into thinking so, but in reality, a SPF 50 sunscreen will block 98% of UV rays while SPF 100 sunscreen blocks 99%, which is just 1% more! Therefore, we should still re-apply sunscreen often, about every two hours as dermatologists suggest. Studies show that a SPF 30-50 sunscreen is strong enough, even for people who are fair-skinned and sensitive to the sun.
Higher SPF sunscreens require higher concentrations of ingredients, which may sound like an advantage. However, some of these ingredients that penetrate the skin may be toxic, leading to tissue damage and hormonal changes. Plus, for those with sensitive skin, some products may induce allergic reactions.
UVA vs. UVB
A broad spectrum sunscreen is best since it will block both UVA and UVB rays. UVA rays can age our skin, causing wrinkles, and UVB is the major cause of sunburn. However, overexposure to either can lead to skin cancer.
A Note on Vitamin A
Studies show that retinyl palmitate (a form of vitamin A) can speed up the development of skin tumors. Nearly 13% of SPF-lip products and 18% of sunscreens contain vitamin A. Vitamin A is an antioxidant that was first added to slow skin aging, but when applied under the sun, it may actually speed cancer growth. Therefore, it is fine to buy night creams with vitamin A, but avoid them in sunscreens!
Common Skin Cancers
Basal cell carcinoma is the most common, usually affecting the face above the lipsSquamous cell carcinoma is very common in the elderly
Melanoma is an aggressive skin cancer, and we should be careful to note the ABCDEs with melanoma:
- Borders are irregular or jagged
- Color variations
- Diameter (more than 6mm is worrisome)
- Elevated skin
Types of Sunscreen and Brands
Besides creams and sprays, there are also gels and sticks.
Gels are good for hairy areas such as the scalp or male chest, and sticks are convenient around the eyes.
Drexel College of Medicine
30 May 2015