Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...Tell Me More
As you may know by now, I am not afraid of the sunlight. Although most dermatologists suggest that we might be better off living in caves and covering ourselves head-to-toe whenever we venture out, my own evolutionary perspective leads me to believe we were designed to get sunlight almost every day and that our health suffers if we don’t get enough.
In fact, recent studies show that, as a result of our shunning the sun, many of us suffer from Vitamin D deficiency and a resulting loss of bone density and immune function (to name a few effects). Some researchers opine that more people die from lack of sun than from too much sun! But, I digress.
I came across an article the other day that piqued my curiosity since it dealt with the combination of running and sunning.
It basically showed that marathoners (of which I was once one) tend to get skin cancer at higher rates than other people. The more they ran, the higher the incidence of skin cancer. My take on what’s happening is that not only are the runners exposed to more sun (which can cause DNA damage in skin cells leading to cancer), but they are also bathed in more free radicals overall from the excessive oxidation of glucose and fats. We know that sun exposure does deplete the skin of the antioxidant Vitamin C.
Moreover, the act of running tends to divert blood flow away from the skin, starving it of additional important antioxidants that could neutralize the free-radical damage in the skin tissues. Add to that the enormous amounts of cortisol marathoners pump out doing this unnaturally high steady-state oxidative work and we not only get the DNA damage, we get the immuno-suppressive effects of the high-stress activity.
So: more DNA damage and a reduced ability to recognize that damage and take steps to eliminate those cells and/or repair the damage. That’s one reason (among many) that I have doused myself with antioxidants inside and out for over 20 years now. That’s also why one of my newest mantras is: a little running is OK – a lot is bad.
This article also brings up other points of discussion, such as whether the reliance on inferior sunscreens was another cause. It appears that for the past 30 years so-called sunscreens have been good at blocking UVB rays (the ones that burn) but not UVA (the ones primarily responsible for DNA damage and skin cancer). The effect is a generation of gung-ho health fanatics (yes, I was one) slathering on sunscreen and running 40, 50 or 100 miles a week. The fact that we didn’t burn only lead us to believe we could stay out even longer. Little did we know that the burning of skin might have been a great first warning to get the hell out of the sun.
Unfortunately, the sunscreen gave us the false notion we were invulnerable. More on that later….
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[tags]sunlight, sun, dermatologist, Vitamin D, Vitamin C, marathoners, DNA damage, DNA, sunscreen, UVB rays, UVA rays[/tags]