Andrea’s stumped by sunscreen: I was shopping today and realized just how many sunscreen options are available today. Neutrogena has a whole line of face sunscreens with SPF ranging from 45-80! How do I know how much SPF I really need?
Fore Brain’s fast answer: 
The quick answer is that SPF (aka Sun Protection Factor) is generally a multiplier of your skin’s ability to resist burning. So if normally your skin burns after 12 minutes of sun exposure, applying sunscreen with an SPF 10 will increase the exposure time to 120 mins before you will get burned. This should help you pick out a proper SPF for your skin. Unfortunately sunscreen quality isn’t all in the SPF, so read on for other factors you should look for in a good sunscreen.
UVA UVB UVWhat?
Sunlight in outer space is composed of radioactive rays, which get filtered out by the atmosphere layers of the Earth. Of all the dangerous rays that the sun emits, the only ones that reach our skin are the UV rays. These rays fall into many categories but the ones we care about when discussing skin damage are UVA and UVB.
When they reach our skin, UVB rays stimulate Vitamin D production, appearance of moles, and can lead to sunburn with overexposure. There are more UVB rays in sunlight in the summertime when the sun is closer to the earth. UVA rays, are not as well known as UVB, and are responsible for tanning of the skin, as well as negative effects of sun exposure like as skin ageing and melanoma (a dangerous type of skin cancer). Unlike UVB, UVA rays are generally present at consistent levels throughout the year.
How do we protect ourselves from UVA and UVB?
This is where sunscreen comes in. Developed in the mid 1900s the aim of sunscreen is to limit sun overexposure and therefore minimize the negative effects and risks associated with sunbathing. The SPF rating that comes on sunscreen bottles is determined by an FDA required in vivo test which involves exposing volunteers’ skin to the sun until it sunburns and then evaluating the protection factor that the sunscreen gave that skin. The general rule is that the SPF is the multiplier of your skin’s normal resistance to sunburn, so if normally your skin would be sunburned after 12 minutes of direct sun exposure, with proper application of and SPF10 sunscreen, it will only get sunburned after 120 minutes.
A note about SPF ratings though. Some studies have shown that sunscreen’s protection factor doesn’t rise as evenly above SPF30 as it does in the ratings below. So for a long time sunscreens in the US were only allowed to be labelled 30+ because the numbers above 30 don’t represent sunscreen’s effectiveness the same way that SPFs 30 and below do. Recently this number has been raised to 50; however, you do need to keep in mind that still SPF50 isn’t twice as good as SPF25 as the number might have you believe.
But what about UVA?
Unfortunately, since the SPF test is mainly for the sunburn prevention properties of sunscreen, and those arise only from UVB, the official FDA test doesn’t shed any light onto how much UVA protection a sunscreen provides. Currently there are several skin pigmentation change tests available to test UVA activity and protection (since tanning is a result of the UVA rays stimulating melanin production and release), but they are not a requirement for sunscreen labelling in the United States. This is quite unfortunate, since UVA rays cause more long-term damage to skin like ageing and melanoma which is quite dangerous.
If you do want UVA protection in your sunscreen, look for products labelled as UVA/UVB broad spectrum, and don’t forget to check the ingredients; zinc oxide, titanium dioxide, avobenzone, and ecamsule (aka Mexoryl) are all effective at blocking UVA and have been approved by the FDA.
The Beauty Brains bottom line
So what is the recommendation here? In my research of sunscreen ingredients, I was very disappointed to come across many theories of some sunscreen compounds being carcinogenic, photomutagens, and reactive oxygen species, meaning that upon deep penetration into the skin they can cause some serious harm to us. This, combined with the fact that many sunscreens are poor UVA blockers, means that sunscreen doesn’t give us the ultimate sun protection which we have all come to rely on so heavily. So my recommendation is this: Try to find a facial moisturizer with UVA blocking compounds I listed above to use year-round to avoid signs of skin ageing, pick a skintype-appropriate sunscreen containing both UVA and UVB protection for the summer, and remember: the best way to minimize skin damage associated with sun exposure is to avoid it all together so wear clothing to shield your skin since the best sun block is a physical one.
Fun Fact: UV rays can be used to kill bacteria and are sometimes used to disinfect drinking water.
References:
http://en.wikipedia.org/wiki/Sunscreen
http://www.medicinenet.com/script/main/art.asp?articlekey=46376
http://www.cosmeticsdatabase.com/special/sunscreens/summary.php
Hansona, K.M., Grattonb, E., Bardeena, C.J., (2006) Sunscreen enhancement of UV-induced reactive oxygen species in the skin. Free radical biology and medicine, 41, (1205-1212).
Loading ...
{ 1 trackback }
{ 11 comments… read them below or add one }
I agree that the best option is to cover up but what about the face? I started walking for an hour every day in a park near my home which is much more enjoyable than the treadmill at the gym. I wear sunscreen on every part of exposed skin and a hat. The sunscreen on my face is in my skin lotion (oil of olay definity spf 15) I am very fair. Am I better off inside at the gym or is spf 15 and hat enough?
My question is similar to Eileen’s. I’m outside a lot, and have been using sunscreens of SPF 30+ (sport types designed for the face), and aside from spending a fortune trying to find one that isn’t so shiny I could signal high-flying airplanes, or so sticky I have to trowel off the bugs later, I am now told that because I have rosacea, I really ought not to be wearing anything above an SPF 15 on my face.
Should I be wearing a non-sport SPF 15 like Eileen’s Oil of Olay? Oof. In any case, I reckon a big ol’ wide brimmed stupidhat is in my immediate future.
Interesting and informative article.
A couple nits to pick, however.
First, the earth is actually closer to the sun in winter, and further away from the sun in summer.
However, the earth is angled in such a way that we get more of the sun’s rays in the summer, even though we’re technically further away. That, plus the fact that there are fewer clouds in the summer and people are outside more is why people burn more in summer than in winter.
My second concern is about your summary of the ingredients in sunscreens, their effectivness, and their potential toxicities.
It’s a little to vague for my liking, and it’s got me kind of worried about what sunscreens are out there. Which ingredients are carcinogenic? Are they going to actually penetrate deeply enough into the skin to be a concern? Where might I find info about UVA protection, even if it’s not regulated in the US?
Beauty Brains are usually excellent at providing clear concise information that eases fears. In this case, it’s a little vague, and it’s increasing my fears. Just a little bit anyways.
A follow-up or clarification would be very welcome, if possible.
I actually use Oil of Olay’s sensitive skin Complete which has UVA UVB in SPF 15 moisturizer every morning. I also spray my neck, arms and legs (areas that will be exposed to the sun), with Neutragina’s Spf 70 Helioplex. I take walks during the day for about 20 minutes to an hour, and always make sure that I have sunblock on. Is this good or is this overkill?
I have had very good results with the Neutrogena Ultracooling Spray SPF70 that Zhariel mentioned. My skin is fair-to-medium. Using this product has allowed me to work in the sun for several hours without getting burned at all. The only problem is it is oily so it is ok when you don’t mind getting a little grimy, but not so good for going to an outdoor wedding. When you need something with a cleaner feel, Neutrogena’s UltraSheer Dry Touch sunblock works very well and does not feel greasy or tacky. Its available in several SPFs including 55 & 70. This product also was one of the few that actually showed decent UVA protection in some independent testing done within the last year. I used to use Coppertone’s UltraSport which did work relatively well and did not have a greasy or tacky feeling, and did not get overly diluted by sweat. It did have the weird tendency to make my nail polish matte and gummy. It also did not test as well on UVA protection.
I have been trying Neutrogena’s AntiAging SPF20 face cream for the last 2 weeks, but my skin seems sensitive to one of it’s ingredients, leaving me with some irritation & breakouts.
As for overkill, There is some medical research that indicates that getting just a little unprotected sun exposure is actually good for you, because it does stimulate Vitamin D production. But I’m not sure where the line between beneficial & detrimental sun exposure exists. If your 20-minute walk is at noon, full sunblock seems like it would be a good idea. If you are taking your walk in early evening, you might be able to skip occasionally.
One area that many women miss with daily sunscreen is their chest where your shirt doesn’t cover. We always think to cover our faces, but we forget that the skin on the neck & chest gets as much exposure, and only the largest of hats will keep sun off your chest when wearing V-neck tops. Now your face looks lovely, but your cleavage looks like a arial map of the Grand Canyon. Another area everyone forgets is the tops of the ears. Baseball caps and ponytails leave this area very vulnerable to burning. And visors may leave your hairstyle intact but they leave your scalp exposed. “Summer Dandruff” may be unsightly, but even worse, skin cancer lesions on the scalp can be difficult to detect early. A hat with a full brim is best.
I guess that’s enough out of me…
Any comment on the theory that sunscreen blocks production of vitamin D, so you reduce your risk of melanoma but increase your risk of cancers that are far less treatable?
In Australia the sunscreens are strictly tested, if you are using a sunscreen which comes from America of Europe the SPF will be way lower than stated on the bottle. The best sunscreen to use is Zinc and a good brand is Intelligent Suncare which is 20% nanozised Zinc it provide broad spectrum UVA & UVB protection plus it is 4 hours water resistant and is a 30 plus SPF and has no chemical absorbers in it so it has no redox activity. It is only sold from doctors offices but they have a website intelligentsuncare.com ..Use Australian made and protect yourself from sun damage.
Elizabeth,
There is no proof that sunscreen represents a significant risk. There is plenty of evidence that being exposed to the sun without sunscreen does pose a risk.
This Vitamin D theory is one being pushed by the Indoor Tanning Association (ITA) and is nonsense. True, there is some recent evidence that Vitamin D may help protect from some types of cancers (like colon cancer). But you can get all the Vitamin D you need through 5 minutes of sun exposure per day, supplements, or 2 glasses of milk.
Telling people to go out in the sun to get their Vitamin D is like encouraging people to smoke because it will reduce stress. Both things work but both will lead to more problems than the benefits you get.
Here is an interesting link regarding sunscreens.
http://uvtalk.com/forum/forumdisplay.php?f=8
“2 glasses of milk” you say?
Not even close to what new recommendations are. Much new evidence suggests that it is nearly impossible to get a proper amt. of Vitamin D through our diets.
Here’s my beef about sunscreen. The cost. I have 3 kids who will be at the pool all summer. For me to adequately apply sunscreen for 3 kids for just one day means going through almost a whole bottle.
Most of these cost between 7-10 dollars a bottle. I was looking at sunscreen yesterday and was overwhelmed by the choices and the amount in each bottle.
Is there a way to adequately make sure my kids are covered with a reasonable cost?
Thanks