Smart Sunscreen Shopping
How to be sure you buy a broad spectrum sunscreen
I just saw a sunscreen billed as "broad spectrum UVA protection". This is misleading, broad spectrum should really mean that both UVA and UVB rays are covered. The FDA’s new rules on sunscreens aren’t perfect, but they will help to get rid of some of the confusion. In order to be labeled as “broad spectrum,” sunscreens must be tested and deemed effective at protecting against UVB rays (which cause burning) and UVA rays (which cause aging skin). Both UVB and UVA rays cause cancer. Sunscreens that don’t protect against both types of rays and have an SPF of at least 15 will carry the warning label: “This product has been shown only to prevent sunburn, not skin cancer or early skin aging.”
Don’t be fooled by high SPF
I’ve heard people say that they don’t even bother with an SPF below 40 or even 50. But the thing is SPF is almost meaningless. First of all, it only relates to UVB rays. Secondly, SPF is measured using a super thick layer, nothing like the way people actually wear sunscreen. In the way that sunscreens are actually applied, an SPF of 30 actually provides the protection of SPF 2.3 to 5.5. The FDA is limiting manufacturers’ claims to an SPF of 30, but given what that really means the only thing for consumers to frequently reapply their sunscreen.
Sunscreen and cancer
It will surprise many people that the idea than sunscreen prevents skin cancer is very controversial. A British scientist looked at all the studies on sunscreen and cancer and concluded that that there was no evidence that sunscreen use prevents the development of malignant melanoma. He still advises wearing a sunscreen, but the best thing is to stay in the shade.
There are some scientists who even believe that sunscreen might actually cause cancers. For example, octocrylene can penetrate into the skin and act as a photosensitizer, resulting in an increased production of free radicals. Free radicals can induce indirect DNA damage and potentially contribute to the increased incidence of malignant melanoma in sunscreen-users compared to non-users. Although this might theoretically apply to other sunscreens, the study that made this conclusion refers only to octocrylene.
Chemical sunscreen safety
Octocrylene isn’t the only sunscreen that acts as a photosensitizer. Oxybenzone has been demonstrated to increase the production of harmful free radicals and an ability to attack DNA cells; for this reason, it is believed to be a contributing factor in the recent rise of melanoma cases with sunscreen users. Some studies have shown it to behave similarly to the hormone estrogen, suggesting that it may cause breast cancer. It has also been linked to contact eczema.
Octinoxate is a moderate hazard, primarily because it can lead to developmental and reproductive toxicity through enhanced skin absorption. It’s a penetration enhancer and is easily absorbed into the skin. It can produce estrogen-like effects and should not be used by pregnant women and children. However, the research is contradictory as to what concentrations are toxic.
Avobenzone appears to be relatively non-toxic and non-irritating to the skin. But some studies show it can be absorbed by the body and secreted into urine, and is therefore not recommended to use on children or pregnant women
Safe sunscreen ingredients
Zinc oxide – this is the best and safest sunscreen ingredient. It offers broad spectrum for UVB and UVA. But you should probably avoid products that use nanoparticle size in case they penetrate the skin and go for “micronized”. I like the zinc oxide sunscreen by Suntegrity.
Titanium dioxide – doesn’t just reflect rays, it also absorbs them. And this means that, like chemical sunscreens, TD is a photosensitizer if absorbed by the skin and resulting in an increased production of free radicals. The question is whether it is actually absorbed by the skin and so its best to go with sunscreen brands that you know use particles (micronized and not nanoparticles) that are too big to be absorbed.
SymHelios – this needs to combined with a sunscreen as it isn’t really a UV-filter, but it is a useful addition to a sunscreen. It stops UVB rays, which are toxic and cause long term skin damage, from binding with receptors in our skin.
Tinosorb – although not approved by the FDA, this European active is worth looking for. Tinosorb, unlike other sunscreen actives, is very stable: it remains 98.4% intact. It can also partly protect other chemical sunscreens from degradation. It appears to have a good safety profile, even though current safety data are insufficient and, since tinosorb is relatively new, it is unclear whether it could produce low-level skin damage or systemic effects with long-term use. Considering that tinosorb is stable, poorly soluble and minimally absorbed by the skin, the risks appear to be low.
Silasoma ~ From Japan, this prevents chemical sunscreen avobenzone from irritating the skin by wrapping it with 100% silk protein, creating a barrier between the skin and the sunscreen preventing any irritation.
New sunscreen alternatives
Also, I am curious about the growing body of research that suggests that plant extracts that are high in antioxidants help your skin prevent UV damage and eating foods high in antioxidants will do the same. I am convinced that my ever-improving diet and the better class of antiaging serums (for example a Duke study found that ferulic acid prevents sun damage) that I’ve been putting on my skin seem to (within reason) preventing sunburn.