Figure 1.1 Flesh Beating UV radiation damages the skin by weakening elastic collagen fibers and by preventing stem cells from rejuvenating the injured area. It also causes free radicals to damage the DNA, which can lead to cancer. UV-C is blocked by ozone, UV-B penetrates the epidermis, and UV-A goes even deeper to the dermis.
The Skinny: How Your Skin Works
Your skin can do more than get you arrested. It’s able to do many things—some good and some we’d rather live without.
IT SWEATS: In a way, our skin acts as our third kidney, detoxifying our bodies. When we exert ourselves, not only do we sweat to cool our bodies, we also increase blood flow, which releases toxins. Though it may not be so great on silk blouses and stair climbers, sweating is something you need to do regularly—not just because of the cardiovascular and fat-frying benefits of exercise, but also because of its body-cleansing function.
IT TANS AND BURNS: Exposure to sun causes an immediate release of stored melanin and stimulates the cells designed to protect you from too much sun, the melanocytes, to produce a protective pigment, melanin. But that process takes several days, by which time you have left the beach with Santa-suit-colored flesh. The sun, unbuffered by melanin, is your skin’s cancer-causing deep fryer.
FACTOID
If stretch marks make your skin look like a highway atlas, the answer isn’t to try to cover them up with creams or makeup. They actually could be a road map to something more serious that’s going on inside your body. First, you need to make sure that your adrenal gland isn’t making too many steroids (that could be a sign of Cushing’s disease). If the marks are less than a year old and still have a purplish hue, you can have them lasered to lighten them, but other than that, only surgery can remove them.
Stop the Burning
Some burns are preventable (sideburns and sunburns), some burns are accidental (darn curling iron!), and some burns are downright dumb (leave the fireworks to the pros, smart guy). No matter what the cause, you can take steps to soothe the pain—and prevent scarring or further damage. First, you’ll want to cool the burn with water or ice as soon as you can to reduce the prostaglandin response and limit the damage. Clean the area with water and a simple soap such as Ivory, Neutrogena, Dove, or Cetaphil to remove dirt and bacteria, and don’t pop any blisters that form. For the small blisters, apply a sterile moisturizer like bacitracin or Neosporin twice a day and leave them intact. They serve as the ideal sterile biologic dressing over the nascent skin that is quickly growing to cover the injured area. Scarring is always worse if the growth of this new skin is hindered. Cover blisters with a fine gauze like Vaseline gauze or Adaptic. The small blisters will dry up and flake off within two weeks.
Note: If the burn is on your hands, face, or genitals (we won’t ask) and is bigger than a nickel, it’s a good idea to let a doc look at it. She may want to treat it with an antibiotic cream called Silvadene that kills bacteria and keeps the wound moist.
IT WRINKLES: We all know that wrinkles generally don’t look all that good—not in dress shirts and not on your skin. In fact, one main indicator of body aging is wrinkles, especially vertical lines above the lips and between the eyes (each of these stereotypically means different things; cigarette smoking and inflammation in your blood vessels cause lip wrinkles, while vertical lines between eyes reflect stress). How do we get wrinkles? In a couple of ways, actually. Since skin is attached to the muscle beneath it, your skin creases when your muscles move. Over time, that creates a well-worn groove. It’s actually like a stress fracture—the repeated bending of skin over the underlying muscle creates inflammation and the collagen gets squeezed together. Young skin stretches and recoils over the muscle, but thinned, old skin loses this ability. And, like an overbent piece of cardboard, it eventually cracks. As we get older, the connections between the skin and underlying connective tissue stretch out, which can cause sagging of the skin. When that happens, gravity pulls down, and the sagging contributes to the formation of wrinkles (see Figure 1.2).
Figure 1.2 Fine Lines Many things can cause wrinkling, including cigarette smoking and sun exposure. Ultimately, it’s caused by thinned, damaged collagen and a loss of elastin fibers (think of it as a kind of stress fracture). When skin loses its elasticity, gravity pulls down on it, and the sagging causes even more wrinkles.
How Skin Ages
When it comes to skin, most of us can spot the good kind a mile away. That’s because we can instantly identify all the characteristics of healthy and beautiful skin—it’s well hydrated, tight and elastic, not overly oily, has clean pores, and all that. But here’s the big myth about skin—that you can stop your skin from aging. No matter what products you use or procedures you undergo, you can’t stop time from pulling, tugging, and tearing at your skin. What you can do, however, is slow it down considerably and encourage all of those things that make your skin appear and be healthier.
Skin aging can happen in the matrix between cells, within the dermis, or on the surface. Here’s how:
In the matrix: Skin aging happens when your collagen becomes damaged and loses its tight weave, and your elastin loses its zing. The fibroblasts (and their DNA) that produce both collagen and elastin are prone to damage from UV radiation, and as they falter, that DNA, which makes collagen and elastin, makes less and/or defective collagen or elastin. Also, glycosaminoglycans (say that three times fast) are large sugarlike molecules that plump up a bit and fill the skin when they bind with water. As you get older, they become more like an old sponge and don’t suck up water as efficiently. The decrease in water content means that the skin becomes like a bad keynote speaker—dull and dry. And those old glycosaminoglycans can link up with proteins and cause yellowing (or browning) of your skin (that’s called glycation, and though it happens to all of us, it’s especially visible in diabetics).
On the surface: Your skin secretes fat (the technical term is lipids). Fatty acids called ceramides help protect an outer layer of your skin called the stratum corneum, so that you have better skin hydration and are less susceptible to irritation. Think of these fatty acids as a coating on you, like the slimy coating fish have on them; they serve as an extra buffer layer between you and the outside world. Ceramide concentrations decrease with aging and with washing with fat emulsifiers like soap and alcohol—our mantra isn’t “use just water” if you touch people and dirty objects, but using just water helps save those ceramides to help you.
Thinner, duller, less vibrant is what you can expect from your skin as you age, but you can control how fast those changes occur in your skin.
FACTOID
Most of the day, gravity pulls your skin down (contributing to facial sagging and wrinkles). When you sleep faceup, gravity exerts a light stretching effect on your skin; when you sleep face pressed to the pillow, you’ll look puffier in the morning and develop sleep lines. There are other reasons for puffiness upon waking. Allergy to dust mites or dust mite poop is common, as are allergies to feather pillows and laundry detergent. These all cause repeated nighttime eyelid swelling. You can prevent leakage of mite poop protein or mites by covering your pillow with a 1-micron case that feels like a pillowcase or a latex cover that feels a bit plasticky; both work to decrease mite allergies and the subsequent puffiness.
In your 40s, your skin becomes thinner and more translucent so capillaries show through. And those capillaries increase in number as a response to years of inflammation from sun damage. Signs of photoaging—such as wrinkles, age spots, and uneven pigmentation—may show up, especially if your parents or you weren’t diligent about sun protection during childhood and in your 20s and 30s. Your skin will produce less oil naturally in your 40s, leading to increased dryness. Cell turnover also is slower, which can cause skin to appear dull.
In your typical 50s, you may experience a deepening of facial lines and wrinkles due to the loss of subcutaneous fat, moisture loss, and accumulated sun damage. As skin elasticity declines, skin may start to sag, especially around the jawline and eye area. If you are postmenopausal, the related drop in estrogen can make your skin thinner, dryer, and more easily