This article is another in our recent series highlighting the benefits of sunshine beyond vitamin D. As always, we begin this article recognizing that too much sun increases your risk for skin cancer. What is perhaps most important about this article is that it comes from the research of a dermatologist, Richard Weller. This is a guy who by his own admission says, “My day job is saying to people, ‘You've got skin cancer, it's caused by sunlight, don't go in the sun.’” And yet he’s also saying we need sunshine, and for reasons that are still being figure out.
He was trying to figure out why, after accounting for all other possible risk factors such as smoking and poor diet, people die from heart disease more as you get further north away from the equator. With all the attention that vitamin D has gotten lately, that was one natural route to investigate because as blood levels of vitamin D go up, heart disease goes down. But as it turned out, but giving people vitamin D supplements did not make that higher heart disease rate go down. The key, as it turns, is not a direct link between vitamin D and heart disease. The link is between sunshine and vitamin D. In this case, the vitamin D levels are a marker for sun exposure, since that is still how most people get most of their vitamin D.
This is where nitric oxide comes in. It is a chemical transmitter in the body that “dilates blood vessels, so it lowers your blood pressure. It also dilates the coronary arteries, so it stops angina.” In short, it is a key to cardiovascular health (among other things). And guess where there are huge stores of nitric oxide that we get from our diet? In the skin! There can be ten times the amount of nitric oxide in your skin as there is circulating in your system, which is where you want it to be. And after years of research, can you guess what was discovered that unlocks and releases nitric oxide stored in your skin? Sunlight! And he showed this to be the case by using UVA sunlight in order to keep vitamin D out of the equation.
Not surprisingly, the latitude effect is present here, just as it is with vitamin D. So the further north from the equator you go, you can still get plenty of nitric oxide being release during the summer, but it goes way down during the winter, thus the higher rate of cardiovascular disease in the north.
You can see and read more about Weller’s work at his TED talk (see link before). What we like best is how he wrapped it up as a dermatologist talking about the benefits of sunshine. These are wise words: “…there are benefits as well as risks to sunlight. Yes, sunlight is the major alterable risk factor for skin cancer, but deaths from heart disease are a hundred times higher than deaths from skin cancer. And I think that we need to be more aware of, and we need to find the risk-benefit ratio. How much sunlight is safe, and how can we finesse this best for our general health?”
Resources for Further Reading (and Viewing)