The Sun: Yes or No?

Summertime means fun in the sun. Or does it?It’s complicated. More complicated than you think.Gone are the days (for most of us) when we brazenly sunbathed, slathered in baby oil, holding aluminum foil-covered reflectors to our faces. (Or was that just me?) We have been well schooled in the evils of El Sol these days, the big one being skin cancer. It is the most common cancer, and far more common in the gray and misty Northwest (where I live) that you would think. It may be that we Northwesterners are so thrilled when we see the sun that we celebrate its appearance with an overabundance of enthusiasm.The other, less dire message about sun exposure concerns aging, as in premature aging of the skin, aka photoaging. Sun exposure dries out the outer layers of the skin (moist skin is youthful skin) and does damage to the deeper collagen layer that gives skin its resilience. Dermatologists believe that photoaging trumps chronological aging in terms of those sags and wrinkles you don’t want to see. Add to this the solid research that sun exposure may contribute to the development of cataracts, and it’s enough to make you want to live in a cave all year.Ah, you say, “Not me. I use sunscreen. I’m safe.” Sorry to deliver some potentially bad news on this front. You may want to take a deep breath:The titanium dioxide nanoparticles increasingly used in sunscreens to protect the skin (the tiny particles directly absorb the radiation from sunlight) are so tiny that some scientists are raising concerns about whether they might do harm by seeping through the skin and into the bloodstream. Back in 2006, the International Agency on Cancer Research classified titanium dioxide as a potential human carcinogen (based mostly on inhalation studies in animals). Although these concerns has been largely dismissed (whew), there are now new concerns focused on the possibility that these nanoparticles could promote skin aging.Yes, that’s right: The stuff we slather on our skin to prevent damage may, in fact, promote it.So...sun BAD; sunscreen BAD.  Stay out of the sun entirely?  Not so fast. There are extraordinary benefits to sun exposure, according to ongoing research. Sunlight is the major source of vitamin D-producing Ultraviolet B radiation. At least 1,000 different genes governing virtually every tissue in the body are now thought to be regulated by D3, the active form of the vitamin, including: calcium metabolism, bone health, neuromuscular and immune system functioning, regulation of hunger, fertility, post-work-our resilience and, get this, the inhibiting the growth of some cancers. There is also research on the possibility of sun exposure reducing blood pressure, cutting heart attacks and reducing the incidence of strokes. (In fact, Scientists at the University of Edinburgh in the UK suggest that the heart-health benefits of sun exposure may outweigh the risk of developing skin cancer.) And, as you probably know, sun exposure has also been associated with reduced risk of seasonal affective disorder.What to do?Maybe this will help: Dr. Michael Holick, a vitamin D researcher with Boston University School of Medicine says that "the alarmist view that you should never be exposed to one ray of sunshine without wearing sunscreen has led to a pandemic of vitamin D deficiency and health problems."  We should be cautious.  Not freaked.How about 20 minutes of unprotected basking -- unless you 1)  have had skin cancer or 2) are very light skinned.  Then 1) it’s the cave for you and 2) 10 minutes?Summertime when the livin’ is easy?  Yeah, right.Non-solar sources of D coming up next.  Stay tuned.