What You Need to Know About Sunscreen
Do you depend on sunscreen for skin protection? Many of us do, but perhaps we shouldn’t. The rate of melanoma diagnosis is increasing at an alarming rate, and the consensus among scientists is that sunscreens alone cannot reverse this trend (EWG report, 2016).
Sunscreens don't work as well as you think
Stanford University dermatologists reviewed CDC national survey data and found that people who relied solely on sunscreen for sun protection had more sunburns than people who reported infrequent sunscreen use but wore hats and clothing to shield themselves from the sun (Linos 2011).
Researchers in Sweden found an increased use of sunscreen by children was linked to more sunburns (Rodvall 2010). Several other studies of real-world sunscreen use found that people who use sunscreen for skin protection during periods of intense UV exposure had more sunburns (Koster 2010, Autier 2007).
Possible explanations are that people aren't using enough sunscreen, are not reapplying frequently enough, and are over-relying on sunscreen alone for protection.
Then there’s the issue of the various claims that sunscreen manufacturers make about their products. Based on the research that’s been completed to date, there is insufficient data to support most claims on the sunscreen bottle. Claims such as ‘waterproof’, ‘sweatproof’ and ‘broad spectrum protection’ don’t hold up. In fact, probably the most misleading is ‘cancer protection’ or ‘prevents cancer’. Sunscreen alone has not actually been shown to protect against certain forms of skin cancer, particularly melanoma, which is the most deadly form of skin cancer.
Melanoma and other skin cancers
Why should we be concerned about melanoma? Well, since 2000, the rates of new melanoma cases among both men and women have been climbing by 1.4 to 1.6 per cent per year (CDC 2014). A number of studies conducted in the 1990s reported a higher incidence of melanoma among frequent sunscreen users (Autier 1998, Beitner 1990, Westerdahl 2000, Wolf 1998).
When it comes to burns, there are two types of radiation that we are most concerned about: UVA and UVB. Both types contribute to the risk of melanoma, particularly with extreme sun exposure. High-energy UVB rays burn skin and directly damage skin DNA, but they make up just 3 to 5 per cent of UV radiation striking the earth’s surface. More numerous UVA rays can be equally damaging without blistering the skin. Because UVA radiation penetrates deeper into the body than UVB, it can cause a different type of DNA damage than UVB (Cadet 2009).
SPF: Is bigger better?
Does SPF or the Sun Protection Factor make a difference? Most of us believe that Bigger Is Better, but there is no definitive evidence of increasing protection as the SPF values increase. In fact, beyond SPF 50, there appears to be little benefit. Properly applied SPF 50 blocks approximately 98% of sunburn rays. Properly applied SPF 100 blocks 99%. When used correctly, sunscreen with SPF values in the range of 30 to 50 will offer adequate sunburn protection, even for people most sensitive to sunburns.
Chemicals of concern
The Environmental Working Group (EWG), a reputable research group in the US, has been putting together a report on the best and worst sunscreens/sun products since 2007. In this year’s report, EWG found at least ¾ of the products they reviewed contained worrisome ingredients. Chief among them are these four:
- Retinyl Palmitate
- Methylisothiazolinone (MI)
Oxybenzone and 4-MBC are hormone disruptors frequently used as UV filters in sunscreens. Oxybenzone could be found in about 70% of the non-mineral sunscreens evaluated by the EWG this year. Retinyl Palmitate and other Vitamin A derivatives have been shown to result in more skin tumours and lesions on animals treated with this ingredient and then exposed to sunlight.
MI, which has been labelled as an inactive ingredient or preservative, was called ‘the allergen of the year’ by the American Contact Dermatitis Society in 2013. In March 2015, the European Scientific Committee on Consumer Safety concluded that no concentration of MI could be considered safe in leave-on cosmetic products (EU SCCS 2014). MI is present in 66 sunscreens assessed in this year’s report.
What to look for in a good sunscreen
With all of these concerns in mind, what can we do to better protect ourselves from the harmful effects of sun exposure? To start, when using sunscreen, pick the right one. Based on current research, mineral sunscreens tend to rate best, particularly those with zinc oxide or titanium dioxide. They are stable in sunlight, offer a good balance between protection from the two types of ultraviolet radiation (UVA and UVB) and don’t often contain potentially harmful additives (EWG report, 2016).
Additional protection measures
In addition to using sunscreen, be smart about your sun exposure.
- Do not use sunscreen as a tool to prolong your time in the sun.
- Cover up! Hats, shirts and sunglasses are the best protection.
- Avoid sunburn.
- Do not use a tanning bed or sunbathe.
- Protect kids! Early life sunburns are worse, so keep little ones out of the hot sun.
- Pick a sunscreen with strong UVA protection.
- Get vitamin D. There is speculation but not proof that adequate levels of vitamin D can reduce the risk of melanoma. We know that vitamin D is good for combatting other types of cancer. Commit to getting screened for vitamin D deficiency.
- Examine your skin. Check your skin regularly for new moles that are tender or growing. Ask your primary care doctor how often you should see a dermatologist.
Sunscreen is a helpful tool for protecting your skin from the harmful effects of the sun when used appropriately. Be sure to use it as recommended, and choose a sunscreen that has minimal or no harmful chemicals in it, particularly a mineral-based one.
Keep these things in mind, and the additional measures you can take to protect your skin, and you can help decrease your risk of developing serious illnesses like skin cancer.
Photo: Sunblock Stripes by earthlydelights on Flickr CC-BY 2.0