Our skin is our first line of defense against all invaders. It basically comes in two layers: the outer “epidermal” layer and the inner “dermal” layer. It is the dermal layer that provides most of the support for nice, taut skin, thanks mostly to the dermal proteins collagen and elastin. Once these proteins are destroyed in sufficient amounts, there is no turning back and the damage is irreversible (although Retin-A seems to offer some benefits to already damaged skin).
Dermatologists will tell you that the most tried-and-true therapy for keeping your skin young is to simply stay out of direct sunlight as much as possible; that tan you long for now will be a major reason why your skin will wrinkle before its time. And I’m not talking about just limiting the time you spend on the beach. Most of the sun damage that accumulates over the years in our skin comes from the daily exposure we get just walking down the street, working in the yard, or waiting for a taxi.
Most of the sunlight that damages our skin is the ultraviolet “B” waves (UVB), which are partially screened out by the ozone layer, but still make it to the earth’s surface in large amounts (UVA rays are also damaging to the skin, but much less so than UVB rays). Note that these UVB rays are not completely blocked out by clouds, so if you spend a lot of time outside in the summer on cloudy days wearing little clothing, you are putting yourself at risk for early wrinkling of your skin. The ubiquity of UVB rays is the reason why our skin wrinkles at varying rates. The skin that is most commonly exposed to the sun year in and out¡ªour face and arms¡ªis the skin that wrinkles first.
Routine use of sunscreens in the summer (or year round if you live in a tropical climate) not only can prevent skin cancer, but help you prevent skin aging as well. Look for sunscreens that block both UVA and UVB. The SPF simply indicates the increased amount of time it will take for your skin to burn, compared to using no protection at all. So if you are using a sunscreen with an SPF of 12, it will take twelve times as long for your skin to burn as it would if you weren’t using any sunscreen.
The UVB rays can damage our skin cells directly or they can produce oxygen free radicals which will then attack the cell membrane, DNA, and cell proteins of skin cells that make collagen and elastin. Once enough of these cells have been killed, and dermal levels of collagen and elastin drop, skin begins to wrinkle. Because free radicals play such an important role in the development of wrinkled skin, anything else you do that results in excess generation of free radicals will also contribute to skin wrinkling over the years. Cigarette smokers generate lots of excess free radicals in their bodies compared to nonsmokers, so their skin tends to wrinkle much more than that of nonsmokers. Diets high in saturated fats carry lots of calories, which can also result in excess free-radical production. In addition, diets high in polyunsaturated oils (such as vegetable oils) can contribute to wrinkled skin because these oils are taken up into the membranes of skin cells where they are particularly susceptible to attack from free radicals.