Causes of Melanoma; Is Sunlight Getting a Bad Rap?

Ask the average person what causes melanoma and you’ll get the standard sun exposure answer.

As a result of this, society has slathered on SPF-80 just to walk to the car for years now.  Has it helped?

No.  Melanoma rates have continued to climb.  In fact, of the seven most common cancers in the US, melanoma is the only one whose incidence is increasing. Between 2000 and 2009, incidence climbed 1.9 percent annually.  While still uncommon in children, the rates of melanoma in this age group has climbed over the years as well.

Clocking in at 44 years of age, I can tell you that myself, Dave Calderone and Mike Conrad were out in the sun pretty much all summer long.  I’m pretty sure we wore some sunscreen in the pool, but that was about it.  There certainly weren’t any rules saying I couldn’t leave the house without slathering myself in enough zinc oxide to look like a circus clown.

And video games?  Pong got boring in the first 20 minutes and Atari didn’t become big until the 80’s.

Compare all of this to children today.  Inside far more often (aka XBox Live) and forced to use an umbrella to block the sun just to go across the street to check the mail.  Despite this, melanoma has increased, and we want to blame the sun?

You won’t get an argument from me that sunburns are a bad thing and tanning so often you begin to look like Jack Palance’s character Curly from City Slickers should not be promoted.  But, as always, we have a tendency to look for the low hanging fruit; the thing that’s not going to cost anyone money when we stop a behavior and may actually make some industries more money (like the manufacturers of sunscreen).

This particular article begins to point out some of the glaring facts:

  1. Melanoma behaves in a similar fashion all over the world regarding age of onset, gender differences and histological subtypes.
  2. If sun exposure was a strong factor, why do melanoma patients often have less photoageing with a lower prevalence of solar keratoses and solar lentigines?
  3. Low vitamin D levels are common in melanoma patients and have a negative impact on risk and survival.
  4. Melanomas in males tend to occur more commonly on the trunk whilst melanomas in females are mostly seen on the legs-both regions of lower sun exposure than the face and arms.

So what does this mean?  While sun damage does play a role, what other factors contribute?

It is likely the usual suspects.  There are clear associations between overweight and obesity and melanoma.  There have been studies suggesting that higher intakes of healthy fats like the monounsaturated fats in olive oil help protect the skin cells from turning into cancer cells.  I’m sure you can fill in the rest of the list.

Either way, we, as humans, were designed to be out in the sunlight.  Avoiding rational sun exposure for fear of melanoma development is part of what has contributed to the current epidemic of low vitamin D levels and everything else that follows from there.


James Bogash

For more than a decade, Dr. Bogash has stayed current with the medical literature as it relates to physiology, disease prevention and disease management. He uses his knowledge to educate patients, the community and cyberspace on the best way to avoid and / or manage chronic diseases using lifestyle and targeted supplementation.