Avoiding the Sun to Avoid Skin Cancer? Recent Studies Challenge That Advice.

My perfect day involves an 85-90 degree day at a beach (preferably with waves), my girlfriend, other friends, a lounge chair, a cooler full of sandwiches and beer.

Honestly…I could repeat that day 10,000 times on various beaches of the world an never get bored. The thing is, I’m a fair skinned German-Irish-Scandinavian mixed breed. I’ve always felt a bit of guilt for going out in the sun, because we’ve been trained that it is like playing Russian Roulette with skin cancer.

Fair skinned people like me are especially warned to avoid sun exposure. Is that sound advice?

[Why am I writing about sun tanning in December? Well…this blog has a large readership from Australia and New Zealand. I figured I would do a summer post that would match their seasons for once.]

Should You Be Worried If You Sport a Tan In the Summer?

Are you risking your long-term health if you spend time outdoors soaking up rays? I can’t answer that question for you. In fact, I am not giving any medical advice here. You have to make your own decisions. Enjoying life in the sun has a built in calculated risk, but so does driving a car to work, or flying in a plane.

That being said, there is some strong evidence against avoiding the sun. In fact the advice of avoiding the sun from 12-4pm, may do more harm than good—>At what time should one go out in the sun?

Outdoor Workers Get Skin Cancer Less Than Indoor Workers?

Here is a link, to a study which found that melanoma has been on the rise for indoor workers, but NOT outdoor workers. Some interesting findings for sure!

“Paradoxically, although outdoor workers get much higher outdoor solar UV doses than indoor workers get, only the indoor workers’ incidence of cutaneous malignant melanoma (CMM) has been increasing at a steady exponential rate since before 1940 (Fig. 1, World Health Organization, WHO, and Connecticut cancer registry). Likewise, the calculated lifetime risk for getting CMM follows the same pattern. In fact, outdoor workers have a lower incidence of CMM compared to indoor workers.”

…Perhaps Indoor UV Exposure is to Blame?

“In the early 20th century, people went against evolution by going indoors during the day to work, which drastically decreased their daily amount of cutaneous vitamin D3 and, along with it, their blood levels. With the addition of larger buildings and sky scrappers, people created an unnatural UV barrier when windows were developed and used in abundance. The UV barrier created by window glass divided UVB from UVA, so that the vitamin D making UVB was excluded from our indoor working environment; only the vitamin D-breaking and DNA-mutating UVA was included. Because this unnatural UV environment existed for decades in buildings and cars, CMM began to steadily increase about 20–30 years later in the mid-1930s.”

[The glass in buildings are dividing UVA from UVB…and this is creating a problem.]

UVB “Makes” Vitamin D3 and UVA “Breaks Down” Vitamin D3

Unfortunately, the glass in buildings allows UVA in, but blocks UVB. Vitamin D3 kills melanoma cells and reduces tumor growth. So vitamin D3 helps prevent cancer. UVB is what helps produce Vitamin D3 in the skin. UVA is what breaks it down. The study puts it best…

“Thus, we propose that along with decreased levels of cutaneous vitamin D3, UVA exposures, which can promote tumor formation and incidence cause DNA mutations, and break down vitamin D3, can together significantly promote melanoma.“

Explanation of Chart: Outdoor workers get a good balance of UVA and UVB rays and therefore have a steady level of Vitamin D3. As you can see indoor workers typically have a poor levels of vitamin D3, except for on the weekends and perhaps summer and vacations.

Sunscreens Block Out the Good Rays as Well!

There are studies that suggest that sunscreens do not help in preventing melanoma. In effect, the sunscreen is doing a similar thing to glass…blocking UVB and allowing in more UVA. So sunscreen isn’t helping much in this regard as well.

Europe Has UVA Blocking Sunscreen and the US Doesn’t!

I just found an amazing site dedicated to sunscreen. Here’s a post you will want to read if you use sunscreen: Sunscreens Exposed – 9 Surprising Truths. “Sunscreen chemicals approved in Europe but not by the FDA provide up to five times more UVA protection; U.S. companies have been waiting five years for FDA approval to use the same compounds”. I want some good European sunscreen! If you are after good sunscreen you can actually look up your brand in the sidebar and they will tell you the UVA protection level.

[Most spray sunscreens in the U.S. rank really bad for UVA protection, but I found one decent one, Kinesys Sport SPF 30 Kids. This is the one I will be using going forward. Important: The SPF 15 version made by this same company does NOT rank well for UVA protection.]

15-30 Minutes of Mid Day Sun Exposure Every Other Day?

It doesn’t take a heck of a lot of sun to get vitamin D to healthy levels. Studies have found as little as 5-10 minutes of sun exposure 3 times per week can boost your vitamin D levels to where they need to be.

My guess is that people with darker skin may need a bit more than that.

My Summer and Vacation Plan of Attack Going Forward

A Strong Case for “Sensible Sun Exposure”

I want to give a shout out to Mark’s Daily Apple, which linked to this outstanding post, by a blog called “That Paleo Guy”: More Sun Science. This guys does an excellent job making the argument that sensible sun exposure helps prevent melanoma, not cause it.

Again, none of this is meant to be medical advice…you need to weight the evidence and decide for yourself whether you want to go out in the sun or not.