Sunbathing the Cure for High Blood Pressure?
Jill writes in to ask: “Maybe you’ll look into the question of whether a bit of sunbathing can lower one’s blood pressure. I heard that last week on Colbert– surely a reliable source (!)”
Certainly, our article on Strategizing Your Sun Exposure, gives a negative view of sunbathing for its skin-aging effects and it’s potential to facilitate skin cancer. The Colbert Report item was based on Edinburgh University research which suggests that 20 minutes of sun exposure can reduce blood pressure and reduce the risk of strokes and heart attacks, which “could be worth the small increase in the risk for skin cancer.”
But on the question of whether sunbathing exerts a healthy effect by lowering blood pressure, some questions remain. For how long does it decrease blood pressure? After a half hour, would you have to lie in the sun for another 20 minutes? And is this an excuse for eschewing blood pressure medication on the idea that you can just lah-de-dah in the sun once a day?
San Antonio dermatologist Dr. Mark Naylor responds: “The FDA would require a large placebo-controlled trial before allowing a drug manufacturer to make such claim; these people are a universe away from being able to justify such a claim. My guess is that an independent group of researchers (who don’t have an axe to grind) would not be able to reproduce even the initial weak and temporary result.”
“On the face of it, this is extremely speculative. These people would first have to show that 20 minutes of sun exposure a day is going to significantly reduce your mean blood pressure throughout the entire day. This would also have to be a fairly significant reduction in average blood pressure over an extended period of time compared to say placebo drug treatment to convince anyone that there’s any real effect here in the first place.”
“A second huge assumption they are making is that the magnitude of any putative effect is going to equal the magnitude of blood-pressure-lowering pharmaceuticals. Although several large studies of drug-induced blood-pressure-lowering do indicate a positive effect on cardiovascular risk status, whatever small (if present at all) postulated temporary reductions in blood pressure from sun exposure seem unlikely to equal the effect of 24-hour drug treatment of hypertension.”
“This is what happens when reporters who are desperate for anything resembling news, find a counter-intuitive and unverified claim from an irresponsible splinter group of PhD’s which feeds the unhealthy desires of the public to do things like smoke cigarettes, drink alcohol, tan intentionally, etc.”