What we know for sure about sunscreen
- It is really good at preventing the dreaded sunburn when applied adequately.
- Decreases the appearance of sun spots also known as solar keratosis.
What we think we know
- Appears to diminish the occurrence of squamous cell carcinoma, which is a slow-growing and treatable skin cancer.
- Doe not appear to impact basal cell carcinoma.
- Sunscreen appears to diminish our ability to produce vitamin D. We currently have a Vitamin D deficiency epidemic.
What confuses the heck out of us
- Some studies report higher incidence while other studies report a lower incidence of the deadliest form of skin cancer, malignant melanoma, among frequent users of sunscreen. This is likely due to increasing exposure to UVA despite adequate UVB sunscreen protection.
- It’s easy to be confused when the experts contradict each other.
The American Medical Association recommends 10 minutes of unprotected daily sun exposure for vitamin D production.
The American Academy of Dermatology states “there is no scientifically validated, safe threshold level of UV exposure from the sun that allows for maximal vitamin D synthesis without increasing skin cancer risk”
What you can do about it
The best protection is physical protection such as protective clothing, hats and sunglasses which protect you from the harmful impact of ultraviolet-A rays on your skin without any harmful chemicals. Staying out of the sun during peak times and looking for a shady environment is also key to your safest defense. Sunscreen should only be considered when doing the previous is unavoidable. The environmental working group recommends mineral cream based sunscreens containing zinc or titanium dioxide as they have very little skin penetration. If mineral based sunscreen cannot be used avobenzone or mexoryl Sx seem like the next safest bet.
Sunscreens to avoid
- Oxybenzone: Found in 60% of sunscreens. It is known to penetrate the skin, it is really absorbent and a potential hormone disruptor.
- Vitamin A (retinyl palmitate): Preliminary but replicable research has shown it to be photocarcinogenic- carcinogenic once exposed to ultraviolet light. Vitamin A is found in over 41% of all sunscreens on the market despite these findings.
- Sprays and powders should be avoided due to a concern of lung inflammation when inhaled.
Check out how your sunscreen measures up at the environmental working group sunscreen database, an iphone app is also available.
Image Credit: Bernhard Aichinger
