Short Days Are Good for You---On the Outside
With the holidays past, northerners enter a gloomy season. We know the sun is coming back, but it's coming too slowly. Call it The Darkness, The Tunnel, The Pits, by whatever name midwinter on the calendar is not a popular time of year.
Furthermore, medical practitioners tell us that Alaska's dark winters can be hard on health. Some people even come down with debilitating illness---Seasonal Affective Disorder, with its appropriate acronym of SAD. Overcoming that takes lightbathing in the correct spectrum; expensive bulbs or a trip to Hawaii ease the symptoms.
Yet, ironically, there may be a gleam of real health in The Tunnel. For one of the human body's most important organs, life without sunlight is a boon. Our skin loves The Pits.
Never mind how pleasant basking on the beach may feel. Hidden in those sunny skies overhead are all kinds of ugly disasters for human skin---wrinkles, spots, drying, thinning, the apparent addition of decades of wear. In scientific terms, it's the problem of photodamage, and it leads to photoaging.
Mind, we're not just talking sunburn here. That's a direct and obvious insult to the system, as clear-cut as the damage caused by a burn from a hot stove. This is more subtle, subsurface stuff, and it takes far less sunshine.
Taking a microscope to a slice of sun-damaged skin reveals destruction at a cellular level. Where once healthy basal cells stood lined up like snugly arranged fat candles in the epidermis, the skin's outer layer, there may now be a jumble in disarray. The smooth, ribbon-like fibers of elastin, responsible for skin's ability to hold (and return to) its shape, are coarser, denser, and less resilient than they are in healthy young skin.
The cause of this sorry state of skin lies within the molecules that compose skin cells. Some vital chemical components of living matter absorb light of a specific wavelength; enough light energy will sever and rearrange some of the bonds holding them together. Among the light-absorbing substances are amino acids, the building blocks of proteins and enzymes, and nucleic acids---the N in RNA and DNA, chemicals that guide cell reproduction, growth, and development,
The villain in this tale of chemical destruction is a high-energy component of sunlight---the shorter-wavelength ultraviolet light, or UVB. It not only cripples some important cellular components when it hits the skin, but also generates further damage by adding energy to oxygen. The so-called active oxygen species thus created appear to be primary culprits in the aging process.
Long-term exposure to significant doses of UVB shows up externally on skin as poor texture, wrinkles, and discolored spots. The longer and more intense the exposure, in general, the more dramatic the visible damage. It's true for all skin colors, even though the natural pigments in darker skin offer some protection from the sun's effects. Given what we now know is happening at the chemical level, it's not surprising that photoaging can be as plain as the nose on your face---or the crevasses and canyons surrounding a nose.
So the next time a friend brags about a forthcoming midwinter jaunt to the sunbelt, smile knowingly. Really, The Pits are good for you. In the darkness of the northern winter, we're all swimming in the fountain of youth. Honest.
