Will Sunbathing Cause Cancer?

I want to write about the two false assumptions I addressed in the previous post where I discussed my conversation with Jack:

1. His doctor is correct in that the sun caused the cancer.
2. What is true for Jack is true for all.

Jack made a logical error of induction. Since he got cancer by exposure to the sun, I would get cancer by sunbathing. Induction is…

…the process of estimating the validity of observations of part of a class of facts as evidence for a proposition about the whole class. –Random House Dictionary

Please, let’s use some simple logic. If the sun caused skin cancer, then all people exposed to the sun would get cancer. But not all do, so the sun does not cause cancer. The sun may exacerbate an underlying deficiency, be that one of geographic location, life style, genetics, thus producing cancer in some people. This puts me to mind something William Dufty wrote in Sugar Blues:

Do you have freckes? If you do, chances are you have a big sugar habit. After you have kicked sugar for a year or so, you begin to notice big changes in the way your skin takes to the sun. Sitting in the hot sun covered with chemical sauce to get a beautiful tan is looking for trouble–especially for women. After you’ve kicked sugar you will discover that sunbathing without any protective lotion is usually possible with little or no risk of burning or peeling. Should your skin turn red, one usually doesn’t burn. I never peel. As a child I used to have painful sunburn on the first exposure to the sun. After ten years of being sugarfree, I am able to loll in the desert for an hour, pick up an instant tan and never have any redness, itching, pain, or any of the old sunburn symptoms.

This isn’t to say you should go out in the sun this weekend unprotected for three hours. Again, let common sense prevail. Those who should be most concerned are people who give no thought to the fact that they haven’t been exposed to it in months and then go on a hike or picnic for a couple hours wearing a tank top and shorts. If you expect to be in the sun for an extended period, then you should preferably cover yourself or, if necessary, wear sunscreen. What do you suppose grandaddy wore?

I just read an article from 2005 that says about 8,000 people die of skin cancer each year. So doctors warn their patients to stay out of the sun. But another article states that 7,600 people die each year from taking aspirin and other NSAIDs. Do you hear doctors warning you not to take aspirin? Why not. How about this? A study published in JAMA states:

We estimated that in 1994 in the United States 106000 (95% CI, 76000-137000) hospital patients died from an ADR [adverse drug reaction]. Thus, we deduced that ADRs may rank from the fourth to sixth leading cause of death.

Okay, so how many doctors are warning you about taking drugs from them? “Sally, now I’m gonna prescribe this painkiller to you. Now it might kill you, so you probably shouldn’t take it.” Meanwhile, four-color posters in clinics show grotesque growths and warn that skin cancer is a killer and you need to stay out of the sun. So we end up with a nation where about 40 percent of the population is vitamin D deficient, which leads to a host of dangers.

How many dermatologists query their patients on their diet and life style? Has anyone bothered to correlate incidents of skin cancer with potential causitive factors, such as diet, climate, life style, level of health and blood values of various nutrients?

Here is an excellent page that describes how vitamin D is made and the effects of deficiency. 

Last year when my blood results showed I was low in vitamin D, my doctor prescribed 50,000 IU ergocalciferol (Vitamin D₂) to be taken every month for five months. I really didn’t care for taking synthetic Vitamin D, but I thought it prudent to boost my levels quickly. (I also noted that formaldehyde was one of the ingredients.) I also began sunbathing.

But then I came across this report, which states:

Vitamins D₂ and D₃ are generally considered to be equivalent in humans. Nevertheless, physicians commonly report equivocal responses to seemingly large doses of the only high-dose calciferol (vitamin D₂) available in the U.S. market….Vitamin D₂ potency is less than one third that of vitamin D₃. Physicians resorting to use of vitamin D₂ should be aware of its markedly lower potency and shorter duration of action relative to vitamin D₃.

In other words, the only Vitamin D supplementation my doctor can give me, D₂, doesn’t last long in my system (but I wouldn’t doubt if the formaldehyde hangs out for a while).

Here’s another point of logic you should consider: You can build up a toxic level of vitamin D in your blood by supplementation, but your body will never create too much by exposure to the sun. What does that tell you?

(It’s late and I haven’t gotten to why you shouldn’t wear sunscreen yet. Sorry about that. I have more to say on this topic and I will post on that soon.)

See also: Why Not Sunbathe? Because the Sun’ll Kill Ya
Benefits of Sunbathing and Risks of Sunscreen