Is Your Sunscreen Toxic?
Worried about the safety of your sunscreen? Learn more about your body's ability to detoxify sunscreen ingredients.
With the days growing longer and the temperatures rising, summer is just around the corner for most of us. As we think about our summer plans, many of us make a mental note to stock up on sunscreen, or do we?
A new study from JAMA found that 4 of the major ingredients in sunscreen that block UV rays go through the skin and actually end up circulating through our body, in potentially toxic levels (Matta et al. 2019).
The FDA does not know what effects these substances might have in the body but they have asked sunscreen manufacturers to do further studies. Additionally, the FDA has issued the following information about sunscreen ingredients:
| GRASE* for use in sunscreens | Not GRASE for use in sunscreens | Insufficient data for use in sunscreens |
|---|---|---|
| Zinc oxide and titanium dioxide | PABA and trolamine salicylate |
Cinoxate, dioxybenzone, ensulizole, homosalate, meradimate, octinoxate, octisalate, octocrylene, padimate O, sulisobenzone,oxybenzone, avobenzone |
*GRASE=Generally Recognized as Safe and Effective
As consumers and parents at Toolbox Genomics, we too want to know what we can do TODAY to help support our families while still protecting their skin.
To help everyone gain a better understanding, we’ve provided a quick overview of the four main sunscreen ingredients from the FDA study and what they do in the body.
|
Ingredient |
Things to Know |
Metabolism* |
|
Octocrylene |
May cause additional ROS (reactive oxygen species) which can damage DNA; hydrophobic |
Excreted in urine: has to be changed from “fat loving” molecule to “water loving” molecule |
|
Avobenzone |
Mixing avobenzone with chlorine water can cause it to break down into more toxic products (see image below) |
Excreted in urine: requires conjugation |
|
Oxybenzone |
Has been linked to allergic dermatitis. Also found in plastics to minimize UV breakdown |
Excreted in urine: has to be changed from “fat loving” molecule to “water loving” molecule |
|
Ecamsule |
Limited information |
Excreted in urine: further information unknown |
*The study established that these compounds are found in urine, but the metabolism that these compounds undergo are based on animal studies.
It is important to gain an understanding of how the body metabolizes (breaks down) these ingredients or other xenobiotics (foreign substances). Our body has 3 main places it can eliminate waste: skin, poop and urine. Urine is one of the most common ways the body releases waste. In order to take a metabolite or by-product, in this case the sunscreen ingredients, and convert it into a something the body can eliminate through urine, the ingredients have to go through phase I and phase II metabolism which happens in the liver, the body’s main detoxification organ system.
How well our body is able to make these different conversions in these phases depends in part on our genes! Some of us have genes that code for adequate enzymes to breakdown these different substances and others of us have lower levels of the enzymes.
When it comes to understanding if you are at an increased risk for these sunscreen ingredients circulating in your body, you want to look at the genes that “conjugate” or are heavily involved in phase II metabolism. Some of these genes include:
|
Gene or Gene Family |
Role in Body |
Location in Body |
|
GST (glutathione s-transferase) |
Conjugates metabolites, making them less active; uses gluathione |
liver, kidney |
|
UGT-1A (UDP-glucuronosyltransferase) |
Plays role glucuronidation; detoxifies metabolites that can’t move out of cells easily |
liver, kidney, intestine, lung, skin, prostate, brain |
|
NAT (N-acetyltransferase) |
Helps detoxify environmental toxins, including tobacco smoke |
liver, lung, spleen, gastric mucosa, RBCs lymphocytes |
What to do:
- Look at the Environmental Working Group for tips on sunscreen ingredients
- Check your current sun care product ingredients on the Skin Deep Database
- Choose mineral based sun block
- Check your detoxification SNPs to see if there are any SNPs that need additional support
- Consider adding additional supplements or nutritional support as your genetic report or lab testing suggests
Take Away Points:
- Sunscreen ingredients do penetrate through the skin and reach the blood, allowing them to circulate through the body
- The spray version of sunscreen appears to be more likely to penetrate through the skin than the cream versions
- Use a mineral based sun block or SPF clothing to protect your skin
- Some of the metabolites of these ingredients may last longer in certain people’s bodies
- Individuals with slower detoxification enzymes may need additional nutritional or supplement support.
Check your Toolbox Genomics detox panel for further information about your genes and their ability to help you detoxify xenobiotics and other metabolites.
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References:
Liston HL1, Markowitz JS, DeVane CL. Drug glucuronidation in clinical psychopharmacology. J Clin Psychopharmacol. 2001 Oct;21(5):500-15. doi:10.1097/00004714-200110000-00008.
Matta MK, et. al., Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial. JAMA. 2019 May 6. doi: 10.1001/jama.2019.5586.
Wang C, et. al., Stability and removal of selected avobenzone's chlorination products. Chemosphere. 2017 Sep;182:238-244. doi: 10.1016/j.chemosphere.2017.04.125. Epub 2017 May 6.
https://www.ewg.org/skindeep/ingredient/706484/MEXORYL_SX/
https://pubchem.ncbi.nlm.nih.gov/compound/4632
https://pubchem.ncbi.nlm.nih.gov/compound/51040
https://www.ewg.org/skindeep/ingredient/700596/AVOBENZONE/
https://www.ewg.org/skindeep/ingredient/704372/OXYBENZONE/
https://pubchem.ncbi.nlm.nih.gov/compound/22571#section=Computed-Properties