Skin Deep

What you need to know about 'hazardous' sunscreen ingredients

In a previous column, I discussed some of the misleading sunscreen reports that surface this time of year. In this second part of the discussion, I will address the claims by many media outlets concerning “hazardous ingredients” in sunscreens.

Lululemon has a quote on its shopping bags that says, “Sunscreen absorbed into the skin might be worse for you than sunshine.” This quote is factually wrong and upset many dermatologists. Daily sun protection is critical because there are ample indisputable studies that demonstrate that UV light causes skin cancer and skin aging.

So, why would Lululemon say this? It is likely because of the controversy surrounding sunscreens that is fueled by the EWG and Consumer Reports stories that come out every May. We will take a look at the “hazardous ingredients” in sunscreen. The EWG can help you identify better SPF options on their website. The question is not, “Should I wear a sunscreen?” but rather, it should be, “Which sunscreen should I choose?” Here is a brief review of “hazardous sunscreen ingredients.”

Dr. Leslie Baumann.jpg
Dr. Leslie Baumann

Vitamin A

  • Retinyl palmitate, a vitamin A (retinol) derivative, was a main focus in the EWG’s 2010 sunscreen report, where they cited a valid scientific study that showed the ingredient had cancer-causing effects in mice when exposed to UV rays. In the retinyl palmitate mouse study, the mice were exposed to UV rays, but did not have on sunscreen. A sunscreen would have protected the mice. However, there is really no benefit to using retinyl palmitate, and there may be a risk, so I would agree to avoid it. It is important to remember that this risk was only seen with retinyl palmitate, and that retinol, tretinoin and other forms of vitamin A do not pose a risk. In fact, these forms of vitamin A will protect the skin from some of the damage that UV causes. Bottom line: It is prudent to avoid products with retinyl palmitate for use in the morning if they do not contain SPF.
  • Retinol, tretinoin, adapalene, and tazarotene – Many people believe that these topical retinoids will make them sun-sensitive. However, this is a myth. Many studies show that retinol, tretinoin, adapalene, and tazarotene actually protect the skin from the sun by blocking the expression of “bad genes” that are turned on by the sun. For example, the sun causes certain genes to product collagenase, an enzyme that degrades collagen in your skin. Retinoids block the production of collagenase and turn on the genes that make your skin produce collagen. In other words, these vitamin A products protect your skin from the sun. Retinol and tretinoin break down upon sun exposure, so they should only be applied at night or they will be ineffective. Bottom line: The vitamin A derivatives known as retinol, tretinoin, adapalene, and tazarotene can protect the skin from sun damage. Retinol and tretinoin should only be used at night.

Chemical sunscreens

Many chemical sunscreens get absorbed in the body and show up in urine and breast milk. They can have hormonal effects when large doses are used, such as all over the body. This is even more of a problem when you think about children who have a larger skin surface to body ratio. Chemical sunscreens can cause allergy and stinging on some skin types, and they build up in the oceans and hurt the marine life. The most problematic chemical sunscreen ingredient is oxybenzone because it can cause allergies and has been shown to have mild estrogenic effects. Other chemical sunscreen ingredients that come under criticism are octinoxate (also called octylmethoxycinnamate). Bottom line: Do not use chemical sunscreen if applying to the entire body, or for use on small children (under age 10) or when pregnant or breastfeeding.

You can argue all day about which ones sunscreens are bad, but they are all safer than going into the sun without any protection at all. So, you must use a sunscreen. Your best bet is to look for a physical sunscreen with zinc oxide, which provides UVA and UVB protection. The problem with zinc oxide sunscreen is that it can look white on the skin, especially when the SPF is above 30. Darker skinned individuals often cannot wear the high SPF zinc oxides.

As a dermatologist, my recommendation is to use an SPF of 15 on your face every morning for your daily routine when sun exposure is less than 30 minutes a day. The lower SPF is a good compromise because it will be less white and more cosmetically elegant, which will allow you to use it every day consistently. When you plan to be in the direct sun for more than 30 minutes, choose a higher SPF.

When you apply the SPF to large amounts of your body, choose a physical sunscreen to reduce the amount of chemicals you are exposed to. I have patients who like to use a chemical SPF on their face and a physical SPF on their body. Make sure you are applying at least ½ teaspoon of sunscreen to your face and an ounce (a shot glass full) on your body. And keep in mind that Lululemon is wrong— even a chemical sunscreen with high amounts of oxybenzone and octylmethoxycinnamate is safer for your health than sun exposure. Sun exposure causes DNA damage, mitochondrial damage, inflammation, immunosuppression, and turns on genes that cause all kinds of havoc with your cells. And no, needing vitamin D is not a good argument, because you can take supplements for that.