By: Dr. Eeks
Natural, homemade sunscreen has become tremendously popular , because folks are scared of the chemicals in many conventional sunscreens. But does natural, homemade sunscreen work to prevent sun burns, sun spots or skin cancer? The short answer is No.
In my latest Causes Or Cures podcast, I interviewed Dr. Julie Merten who recently did a study on natural, homemade sunscreen recipes on Pinterest. Dr. Merten is an associate professor of public health at the University of North Florida. She is the Editor-in-Chief of the Florida Public Health Review and Chair of the Skin Cancer Prevention Task Force for the Northeast Florida Cancer Control Collaborative. Her research involves behavioral skin cancer prevention. Her recent work on natural, homemade sunscreen recipes on Pinterest was published in Health Communication: “Pinterest Homemade Sunscreens : A Recipe for a Sunburn.”
My podcast with Dr. Merten is worth listening to, because we talk a lot about various aspects of sunscreen: What works, what doesn’t, the SPF riddle, and in general, who or where people are getting their health and wellness advice from. That last one is important, since social media has become folks’ go-to for wellness advice. I often see trendy wellness sites or wellness “influencers” post a spiffy graphic with a bit of health advice that isn’t backed by quality evidence, doesn’t make sense or is simply not true. Personal anecdotes are nice, and can be helpful, but they aren’t quality data. My advice is this: When you are searching for wellness advice online:
1) Look for randomized controlled trials, meta-analyses or well-done cohort studies for evidence
2) Look at the job and/or credentials of the person giving the advice (And if he/she doesn’t have credentials, does he/she understand science/biology well or at the least, how to differentiate between quality evidence vs poor evidence?)
3) Is the person/website selling anything?
4) At the end of the day, do you trust the person/website?
Advice rooted only in anecdotes or tradition does not mean it’s not useful. It might be very good and helpful, and simply not studied in a large trial. Trials are tedious and expensive. Still, to make an informed decision about a product or taking someone’s health advice, it’s important to know the type of evidence you are working with.
Back to natural, homemade sunscreens:
If you listen to my podcast with Dr. Merten, you’ll learn who is making these homemade sunscreens and the ingredients they are using. You’ll hear that over 70% of these natural, homemade sunscreen recipes offered insufficient protection from the sun. You’ll hear about their “SPF” ( Sun Protection Values) values that were not scientifically derived from any sort of solar simulator, but seemingly pulled from the air and listed as fact. I also brought up the fact that mainstream sunscreen companies notoriously exaggerate their SPF values to trick and entice sunscreen users. Dr. Merten acknowledged that this happens and said it’s wrong. She said that an SPF value above 30 is essentially meaningless. As someone who was always a sucker for the highest SPF, lately I buy nothing over 30.
Dr. Merten also addressed common, legitimate concerns when it comes to sunscreen: Is it inhibiting Vitamin D absorption? What about the chemicals that may be endocrine disrupters? What about the coral reefs?
I use a bunch of natural products ( some have good evidence and some don’t), but sunscreen isn’t something I mess around with. I’m pale, I burn easily and skin cancer runs in my family. I need to know my sunscreen works. That said, I’m also concerned about the chemicals in sunscreen, and brought up that concern with Dr. Merten in the podcast. The chemicals I am talking about are avobenzone and oxybenzone, also commonly found in nail polish and hairspray. Both have been linked to disrupting hormones and birth defects if exposed while in utero. I asked her about a recent study published in JAMA. It was a randomized controlled trial that showed that the application of 4 popular sunscreen brands raises our plasma level of avobenzone and oxybenzone above the recommended FDA threshold. To me, that’s concerning. Dr. Merten knew about the study and gave her opinion on the podcast. (It’s interesting, so listen!)
The good news is that we can avoid the chemical-containing sunscreens altogether, and it’s not by using a natural, homemade sunscreen we are unsure of. Sunscreen is either a chemical blocker ( like the ones containing Benzones) or it is a physical blocker. The physical-blocking sunscreens contains Titanium Dioxide and Zinc Oxide that, instead of producing a chemical reaction, physically block the sun’s rays. These are mineral-based sunscreens, and those are the ones I use.
In conclusion, I want to stress that sunscreen isn’t proven to stop skin cancer. It helps prevent it, but it’s not a cure-all. If you are worried about sun exposure, it’s most important to stay out of the sun or wear wide hats and big sunglasses when you are in the sun. In a later blog, I am going to come back to the Vitamin D issue and how it relates to sun exposure, because it’s an important one.
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