Skin Story

Many of us have spent significant chunks of time this summer dabbing and smearing lotion on ourselves and our family members. It used to be called suntan lotion; now it’s called sunscreen or even sunblock. Some worried people search constantly for ever-higher SPF numbers due to fear of sunburns and dermatologist cautions about sun-related skin cancers.

The sunscreen issue is interesting when you think about it. Our ancient ancestors obviously spent a lot of time outdoors, hunting and gathering, and they didn’t have ready access to drugstores that provided rows of 50 SPF lotions. So how did they deal with the sun?

I ran across an interesting article by an anthropologist that tries to answer that question. He notes that the early humans didn’t fear the sun, thanks to their skin–specifically, the crucial protection provided by the epidermis, the outer layer of skin that adds new cells and thickens with increasing exposure to sunshine in the spring and summer, and eumelanin, a molecule that absorbs visible light and ultraviolet light and causes skin to darken due to sunshine. Because early humans didn’t radically shift their sun exposure by, say, hopping on a jet to Costa Rica in the dead of winter, their skin could adjust to their local conditions and provide all the sun protection they needed. In effect, their skin became well adapted to providing the protection needed in their local area. (Of course, they may have looked a bit leathery by modern standards, but they weren’t worried about such things in their desperate bid for survival in an unpredictable and unforgiving world.)

The article posits that the change in the relationship between humans, skin, and sunshine occurred about 10,000 years ago, when home sapiens began to develop more of an indoor life and exposure to the sun began to distinguish the lower class from the upper class. People became more mobile, too. The disconnect was exacerbated when people started to take vacations to warmer climates that abruptly changed sun conditions without a ramp-up period allowing their skin to adapt. In short, the trappings of civilization and class removed the previous balance between skin and local conditions and deprived our skin of the time needed to adjust to gradually increasing sunshine.

Does that mean you should try to recreate the former balance by staying in the same place, spending as much time as possible outdoors, and accepting the wrinkles and leathery look that are the likely result? The article says no, because your skin probably isn’t matched to your current location, and your indoor time is going to interfere with the process. That means we all need to keep dabbing and smearing to prevent sunburns and skin damage.

Incidentally, the highest-level sunscreen that is available now is 100 SPF, which is supposed to block 99 percent of ultraviolet rays. The ancients would shake their heads in wonder,

Let The Sun Shine In?

I recently returned from a beach vacation.  One of our daily rituals was slathering on SPF 50 sunscreen to try to protect ourselves against the blazing sunshine.  We wanted to be in the warm sun rather than the gray cold Midwest, obviously, but we’d accepted the healthcare cautions about sunshine and skin cancer, and so the sunblock went on.

But what if the healthcare cautions that led to our lubing up are wrong — as in, 180-degree wrong?  What if exposure to sunshine is not only not bad for you, but in fact it helps you to be healthier in countless ways, by effectively and efficiently producing vitamin D, lowering blood pressure, making you feel happier, and having other therapeutic benefits?

That’s the intriguing conclusion of recent research that started with a look at the value of vitamin D supplements — which many people who avoid the sun are taking to try to compensate for the lack of solar-produced vitamin D.  Low vitamin D levels are associated with lots of bad stuff — cancer, diabetes, obesity, osteoporosis, heart attack, stroke, depression, cognitive impairment, autoimmune conditions — and vitamin D is required for calcium absorption and good bone health.  So vitamin D supplements should help, right?  But the research showed that vitamin D supplements weren’t having any discernible impact on cancer, heart disease, or stroke.

Scientists scratched their heads and looked into the unexpected result, and started to find evidence that it wasn’t high vitamin D levels that prevented the bad conditions.  Instead, the presence of vitamin D was just a marker, and the real cause for the positive health effects was that sunlight that was producing the vitamin D.  The people who had the high vitamin D and were avoiding the bad conditions were getting plenty of sunlight.  Exposure to sunshine also causes the skin to produce nitric oxide, which dilates blood vessels and reduces blood pressure — which, as the article linked above points out, helps to explain why “rates of high blood pressure, heart disease, stroke, and overall mortality all rise the farther you get from the sunny equator, and they all rise in the darker months.”

And the vitamin D/blood pressure effects may just be the start.  The article continues:  “Sunlight triggers the release of a number of other important compounds in the body, not only nitric oxide but also serotonin and endorphins. It reduces the risk of prostate, breast, colorectal, and pancreatic cancers. It improves circadian rhythms. It reduces inflammation and dampens autoimmune responses. It improves virtually every mental condition you can think of. And it’s free.”

But wait — won’t getting more sunshine cause skin cancer?  Yes, there is that risk — but the article points out that skin cancer is not nearly as lethal as the other diseases and conditions that exposure to sunlight helps prevent.  And, additionally, people who regularly get sunshine, avoid sunburns, and keep their tans going — like outdoor workers — are much less likely to experience melanoma, the less-common but potentially fatal kind of skin cancer.  In fact, the evidence indicates that long-term exposure to sun is associated with lower melanoma rates.

All of this will come as a surprise to people who are scared to death of skin cancer and buy sunblock by the carload, but it makes sense from an evolutionary standpoint.  Our half-naked distant ancestors didn’t have SPF50 to apply, and they were exposed to the sun on a much more prolonged basis than modern, largely indoor humans.  It makes sense that humans would evolve in ways that would favor those who were more efficient in using that abundant, constant sunshine in positive, healthy ways.

Think about that the next time you’re carefully applying that SPF50 sunblock and popping down vitamin D pills.

Sunburn Season

It’s been brutally hot in Columbus the past few days, with the mercury reaching the high side of 90.  As a result, I’ve gotten my first sunburn of the season.

There are people who can “lay down a base” without getting burned and gradually get darker and darker, without telltale peeling, as the summer progresses.  It’s as if they have special tanning knowledge, passed down from generation to generation like the Rites of Ephesus.

I’m not one of those people.  I go directly from winter white to a blazing brick red that quickly peels off in great, sweeping curtains of skin the size of dish towels that you can roll up and toss in the waste basket.  After that distasteful condition passes, I’m set for the summer with a permanent ruddy red face.

This happens no matter what I try.  Today, for example, I smeared heaping handfuls of Coppertone on head, ears, face and neck in hopes of avoiding the burn.  After a few moments in the sun playing golf, however, my sweat glands kicked into high gear and the resulting cascade of sunscreen runoff left me partially blinded and milky eyed.  After swabbing the perspiration off with a towel, I may as well have not applied any suntan lotion in the first place.

And now I sit, with that fine, bright burning feeling on my skin, waiting for the peeling to begin.  Summer has arrived.