There has been a lot of media buzz lately about potentially dangerous effects related to the chronic use of sunscreen. While I do believe we have to examine and understand any product that we apply to our bodies, there is a great deal of confusion surrounding this topic.
First of all, there are two main categories of sunscreens – chemical (sometimes called “organic”) blockers and physical (sometimes called “mineral” or “inorganic”) blockers. The chemical blockers provide protection to the skin from ultraviolet (UV) rays by absorbing them while the physical blockers create a barrier that limits the amount of UV that can pass through the skin.
In reality, all ingredients in all sunscreens are man-made chemicals, so nomenclature such as “organic” “mineral” “natural” is definitely misleading. The most common active ingredients in the chemical blockers are avobenzone and oxybenzone while the mineral sunscreens typically contain zinc oxide and/or titanium dioxide. There have been many misleading reports revolving around the ability of oxybenzone in particular to cause cancer. This information stems from a single paper in a low-level scientific journal that demonstrated a toxic effect on rats who were FED this chemical in obscenely large amounts. The authors concluded that oxybenzone can disrupt the normal hormonal balance in the body and thus should be avoided.
However, to achieve these levels in a person rubbing oxybenzone on the skin, one would have to rub it on from head to toe every day for 70 YEARS! There are many things that we come in contact with throughout our lives that may be lethal if ingested at these massively large quantities, but there have been NO reports linking the topical application of sunscreen of any kind to the development of cancer in humans. This includes other unsupported buzz about ingredients such as retinyl palmitate and vitamin A.
A more recent but absolutely more scientifically-based report appeared in 2019 that demonstrated the ability to detect the active ingredients of chemical sunscreens in the blood of humans after application on the skin. Twenty-four people applied sunscreen over 75% of their bodies 4 times per day for days and researchers measured the concentration of sunscreen ingredients in their blood over the following week. What they found was that the levels of these chemicals were detectable in the blood within hours of application at a level greater than 0.5 nanograms per milliliter (ng/ml).
So what does that mean? The Food and Drug Administration (FDA) sets this level of 0.5ng/ml as the maximum concentration above which additional studies have to be conducted to determine if a given chemical is harmful to humans – that’s it!
Never in any part of the study or the FDA’s response to the study did anyone suggest that these chemicals are harmful or should be pulled from the market. All that was concluded was that additional testing needed to be done to determine if the ingredients of chemical sunscreens cause human harm when applied over large areas of the body for several days in succession.
Believe me, I am all for more testing, but at no point has there ever been a study to show harm to humans by the application of sunscreen. What HAS been shown time and time again is that there is great to harm to humans when they DON’T apply sunscreen to their skin!
Ninety-nine percent of all skin cancers and almost all deaths related to skin cancer are a result of unprotected sun exposure and damage from UV rays and sunscreens are designed specifically to block UV rays. I am in favor of the FDA conducting more tests, but for the time being we have effective products that reduce the incidence of sun damage and the development of skin cancer and those should be used on a regular basis.
If you want an abundance of caution, you can stick to the mineral sunscreens while the FDA works on clarifying the situation (or maybe if you’re pregnant or breastfeeding), but this will likely take many years and I personally find the mineral sunscreens harder to apply to my skin. Again, there have been no studies to link the use of sunscreen to cancer in humans, but so many millions of skin cancers may have been avoided had sunscreen been used.