Summer will be here in a week and that means sun exposure and taking precautions to avoid burning our skin. Without much thought other than what the SPF number is (sun protection factor) on the sunscreen lotion we use when we apply this to our skin, we think little of what chemicals we are applying.
It’s a confusing system, but SPF 15 blocks 93% of UVB, a SPF 30 blocks 97%, a SPF 50 blocks 98%, a SPF 100 blocks 99%, and if you get red in 20 minutes when your skin is unexposed then a SPF 15 will delay redness by 15x or for about 5 hours. So, a SPF 100 only gives 1% greater protection than SPF 50 to UVB rays with the mistaken idea that you can stay in the sun 50x longer. What most don’t realize is that sunscreens do not block UVA which makes up 95% of ultraviolet radiation, penetrates more deeply into the skin, and causes greater damage. But, I digress. The real problem is what is doing the blocking, and whether it is chemical or mineral.
Nearly seventy percent of sunscreens use two chemical ingredients either oxybenzone or octinoxate as a blocking agent. It is now known that these chemicals are extremely bad for both the environment and for us. Oxybenzone can cause damage to coral reefs at a level of 62 parts per trillion. This is equivalent to one drop of water to six and a half Olympic sized pools of water. It is estimated that there are 14,000 tons of sunscreen entering waters around coral reefs each year. Research is showing that these two chemicals cause bleaching of the coral reefs and kills them. Coral reefs cover less than 1% of the ocean floor but support nearly 25% of all marine life. In the past few decades coral reefs have declined by 40% in Hawaii, 50% in the Great Barrier Reef, 85% in the Caribbean, and 99% in the Florida Keys.
These chemicals aren’t just in sunscreens, they are also in lip balms and other skin care products. The Center for Disease Control said that oxybenzone can be found in 97% of all Americans. Hawaii just became the first state to pass a bill to ban sunscreens with oxybenzone and octinoxate effective in 2021. Oxybenzone and oxtinoxate mimic hormones and have been linked to cause endometriosis, lower sperm counts and infertility in men along with increased cancers in both men and women. According to the C.D.C. adolescent boys using sunscreens with these chemicals had lower testosterone levels and a study from the University of California showed girls using cosmetics with these chemicals were able to show lowered levels after switching cosmetics without them. A researcher at the University of Zurich showed that these chemicals can pass through breast milk.
While the incidence skin cancer is rising for reasons other than UV exposure, such as ozone layer depletion. How can we get the benefits from the sun such as vitamin D and protect ourselves from the dangers of the sun without destroying our environment and ourselves in the process?
The vitamin D expert
Dr. Michael Holick started his vitamin D research in 1969 and was the one who identified the major circulating form of vitamin D (25-hydroxy) in human blood. He got his PhD for the identification of the active form of vitamin D, made by the kidneys. He developed a free app for our phones http://dminder.ontometrics.com/ so that we can track our exposure and the amount of vitamin D we make each day. It automatically does this based on where we live, the altitude, the time of year, and our body size along with how much clothing we are wearing.
If sun exposure results in a light pinkness to your skin, (not a skin burn) you have received what is called a minimal erythemal dose. A full body exposure would equate to 20,000 units of vitamin D. Exposure to arms and legs would probably measure out to 4000-5000 units of vitamin D. A study done on Masai herders in Kenya showed that their blood 25-hydroxy vitamin D levels were about 50 ng/ml. For those in northern climates we would need about 4000-5000 units of vitamin D per day to get the ideal 40-60 ng/ml level. Toxicity of vitamin D wouldn’t occur until you were at 150-200 ng/ml.
Dr. Holick’s main recommendations are to avoid burning and to avoid exposure to the face. It’s only 4% of the body’s surface, gets the most sun exposure, is the most sun damaged and the most likely area to have a non-melanoma skin cancer. The back of the hands is another area to protect. However, the arms and legs are good areas for exposure and we should spend enough time exposing those areas without causing a mild sunburn. After that, cover up with clothes rather than sunscreen. However, at times that isn’t practical so here are some suggestions and comments.
Zinc oxide and Titanium Dioxide are used as a non-toxic mineral based sunscreen. It can block both UVB and UVA. According to the Enviornmental Working Group’s sunscreen report, 216 beach and sport sunscreens met with their criteria for safety. However, after viewing the list I think they included too many sunscreens with questionable ingredients that should be avoided. For instance, they gave Oxybenzone a deservedly high hazard score of (8), Octinoxate a score of (6), but other chemicals such as Homosalate, a (4), and Octisalate, a (3). Interestingly they gave 2 chemicals Avobenzone and Mexoryl the same hazard score (2), as Titanium Dioxide and Zinc Oxide. Although Avobenzone doesn’t appear to have any major toxicity issues, it breaks down within 30 minutes leaving your skin vulnerable to damage. Mexoryl, used in European sunscreens is awaiting FDA approval.
I found the website https://www.beautifulwithbrains.com/category/sunscreen/ a little more discerning than the E.W.G. website. These were the top three listed.
Badger Balm ($42.00): 18.75% zinc oxide + natural extracts.
EltaMD UV Pure BroadSpectrum SPF 47 ($24.50): 10% zinc oxide + 5.5% titanium dioxide + water-resistant technology + dry finish for oily skin.
Replenix Sheer Physical Sunscreen Cream SPF 50 ($32.00): 13.75% zinc oxide + antioxidants.
UVB ray exposure is needed to produce vitamin D in our bodies but based on the information from Dr. Holick the sun needs to be above the 35-degree point in the sky for us to get it. Before the sun reaches that point in the sky and after the sun begins to set below the 35-degree point, we no longer get exposure to UVB rays and cannot make vitamin D. For those of us who live within 35-degree latitude from the equator, there is some point in the day where you could get exposure for vitamin D. Those living outside of the equator above 35-degrees, (above Atlanta) the sun’s position may be outside of vitamin D production for part of the year. Additionally, for every 1000 feet of elevation your vitamin D production increases by 11% during those peak times. The benefits of sunlight on the human body are many. Beneficial nitric oxide from UVA reduces blood pressure and UVB produces ACTH, Beta endorphins (happy chemicals), substance P, and Vitamin D. And contrary to some urban myths, none of these benefits can be washed off in a shower!