EWG’s 2017 Guide to Sunscreens
The Problem With Vitamin A
A study by U.S. government scientists suggests that retinyl palmitate, a form of vitamin A, may speed the development of skin tumors and lesions when applied to the skin in the presence of sunlight (NTP 2012). Officials in Germany and Norway have cautioned that retinyl palmitate and other vitamin A ingredients in cosmetics could contribute to vitamin A toxicity due to excessive exposure (German BfR 2014, Norwegian SCFS 2012a).
The evidence for these effects, while not definitive, is troubling. The sunscreen industry adds vitamin A to nearly 14 percent of the beach and sport sunscreens, 15 percent of moisturizers with SPF, and 6 percent of all SPF-rated lip products in EWG’s 2017 sunscreen database.
Skin damage and cancer for sun-exposed skin
Vitamin A is an antioxidant added to skin products because manufacturers believe it slows skin aging. Oral ingestion of vitamin A can reduce the risk of squamous cell carcinoma in people at high risk for skin cancer (Moon 1997), but the 2012 federal study raised the possibility that it may speed the growth of cancerous tumors when used on skin exposed to sunlight.
Scientists have found that vitamin A can spur excess skin growth, known as hyperplasia, and that in sunlight, retinyl palmitate can form small molecules called free radicals that damage DNA (NTP 2000).
In 2010, EWG analyzed raw study data published on the website of the National Toxicology Program, the interagency federal research group that had tested retinyl palmitate, in concert with the federal Food and Drug Administration’s National Center for Toxicological Research. EWG concluded that the government scientists had produced evidence that the development of skin tumors was accelerated when hairless mice were coated with a cream laced with vitamin A and then exposed to ultraviolet light every day for a year (NTP 2009). The daily exposure was equal to nine minutes of sunlight at its maximum intensity.
In January 2011, the NTP Board of Scientific Counselors affirmed NTP staff’s conclusion that both retinyl palmitate and retinoic acid, another form of vitamin A, sped development of cancerous lesions and tumors on UV-treated animals (NTP 2011, 2012). Sunscreen scientists and trade groups dispute EWG’s warning about retinyl palmitate on sun-exposed skin (Wang 2010).
At this point, the NTP and FDA have spent well more than a decade studying the photocarcinogenicity, or UV-catalyzed skin cancer potential of vitamin A ingredients. In 2012 FDA launched a follow-up study to confirm the finding in a second lotion using the same hairless mouse model. The European Scientific Committee on Consumer Safety reviewed the hairless mouse study and concluded that the NTP study “may indicate” that the ingredients are photocarcinogenic, but it is difficult to extrapolate this finding to risks of skin cancer for humans due to differences in skin sensitivity between hairless mice and humans (SCCS 2016). EWG calls for sunscreen makers to voluntarily stop adding this ingredient to sunscreens until there is proof that it can be safely used on sun-exposed skin. More details on the studies of vitamin A and skin cancer are available here.
Cosmetics can contribute to vitamin A toxicity
In a separate issue, the German and Norwegian governments have cautioned that retinol and other vitamin A ingredients in cosmetics could cause people to take in toxic amounts of vitamin A.
Too much pre-formed vitamin A, including retinol, retinyl palmitate, retinyl acetate and retinyl linoleate, can cause a variety of health problems, including liver damage, brittle nails, hair loss, and osteoporosis and hip fractures in older adults. Older women at risk for osteoporosis should avoid excessive vitamin A because it undermines bone density. Children can also suffer a variety of ill effects from too much vitamin A (Norwegian SCFS 2012a). Excessive vitamin A can cause serious skeletal birth defects in a developing fetus as well. For that reason, Norwegian health authorities have cautioned women who are pregnant or breastfeeding to avoid products with vitamin A (Norwegian SCFS 2012b).
Many Americans and Europeans get a lot of pre-formed vitamin A in their diets, and Norway and Germany have cautioned that any additional exposure from skin products could increase the number of people at risk for hypervitaminosis, or excessive vitamin A. German regulators recommended restricting the concentration of vitamin A in cosmetics for face and hand care, and barring the substance in lip and body care products (German BfR 2014).
The cosmetics industry argues that there is very little absorption of vitamin A compounds from skin lotions. In one study 28 female volunteers with low vitamin A diets applied creams with 0.3 percent retinol or 0.55 percent retinyl palmitate over their entire bodies for 21 days. Researchers demonstrated that there was no increase in vitamin A levels, compared to a significant increase in concentrations when the women drank milk fortified with the same amount of vitamin A (Nohynek 2006). The European SCCS reviewed this and other dermal studies, and concluded that the lack of blood level changes didn’t eliminate concerns about overexposure (EU SCCS 2016).
In 2016 the European SCCS reviewed use in other body care products. It concluded that it would not restrict pre-formed vitamin A in cosmetics because it was unlikely that these products alone would expose consumers to harmful amounts of the vitamin. But since retinyl palmitate and related ingredients are not used in European sunscreens, additional exposure from these products was not considered in the analysis. The committee noted that when added to the significant exposures from food, “any additional source of exposure, including cosmetics products, may exceed this [recommended daily upper limit]” (European SCCS 2016).
Consumers at risk
EWG remains concerned about the contribution of retinoids in skin lotions, lip products and sunscreens to the risk of excessive vitamin A exposure. Americans have high levels of pre-formed vitamin A in their diets from liver, fish oils, and the intentional fortification of cereals and milk. The ingredients added to fortified foods are widely used in cosmetics. Retinyl palmitate is added to at least 120 sunscreens, nearly 70 SPF-rated moisturizers and 8 lip products. Retinyl acetate and retinyl linoleate are in more than 380 personal care products in EWG’s Skin Deep® database, including lotions and lip products.
EWG urges U.S. regulators to assess exposures to vitamin A, and consider restrictions on food fortification and body care products for populations at risk of overexposure.
Six years after EWG sounded the alarm about retinyl palmitate, the FDA still hasn’t completed follow-up studies that will allow the agency to take a position on the safety of vitamin A and related chemicals in cosmetics and sunscreens. Most cosmetics companies have not removed these ingredients from sunscreens and other skin and lip products.
EWG recommends that consumers avoid sunscreens and other skin and lip products containing vitamin A, retinyl palmitate, retinol, retinyl acetate, retinyl linoleate and retinoic acid.
If you are undergoing skin treatments for medical purposes with any form of vitamin A, you should do so in consultation with a dermatologist, apply treatments at night if possible, and always practice strict sun avoidance when using these powerful ingredients on your skin.
Posted in Beauty
01.03.18 4:33 PM