The vast majority of undesirable consequences of aging skin occur in individuals who are repetitively exposed to the sun, notably farmers, fishermen, construction workers, lifeguards, outdoor enthusiasts, and sun-worshippers. People who live in areas where the earth’s protective ozone layer is thinning, namely in southern climates and at high altitudes, are more likely to have sun-damaged skin.
Ethnicity also influences a person’s susceptibility to aging skin. Individuals with fair complexions, and those who have blue, green, or gray eyes, and red or blond hair, are more susceptible to photoaging than are darker-skinned persons. Overall, African Americans develop fewer wrinkles, have fewer lesions, and experience less sagging of facial skin than do whites, presumably because the larger amount of melanin present in their skin helps block the penetration of UV radiation. Nonetheless, premature aging from sunlight can affect all ethnic groups.
Cigarette smokers are more prone to wrinkles and skin cancers. According to one study, heavy smokers are almost five times as likely to have wrinkled facial skin than nonsmokers. In fact, heavy smokers in their 40s often have facial wrinkles more like those of nonsmokers in their 60s. A recent study of 25 sets of twins found smokers to have thinner skin than non-smokers, in some cases by as much as 40%.
Avoiding Intense Overexposure to Sunlight
Staying out of the Sun.The best way to prevent skin damage in any case is to avoid episodes of excessive sun exposure, particularly during the hours of 10 AM to 4 PM when sunlight pours down 80% of its daily UV dose. Reflective surfaces, such as water, sand, concrete, and white-painted areas should be avoided. Clouds and haze are not protective, and in some cases may intensify UVB rays. Ultraviolet intensity depends on the angle of the sun, not heat or brightness. For example, UV intensity in April (two months before summer starts) is equal to that in August (two months after summer begins). The U.S. Weather service provides a UV index, which ranges from 1 to 10 ; the higher the index numbers the greater the exposure to UV rays. This index is valid for about a 30-mile radius around the city from which the broadcast originates. Currently, the computation of the UV Index does not include the effects of variable surface reflection (e.g., sand, water, or snow), atmospheric pollutants or haze. Higher altitudes appear to reduce the time it takes to burn. (One study suggested, for example, that an average complexion burns at six minutes at 11,000 feet at noon compared to 25 minutes at sea level in a temperate climate.) Sun lamps and tanning beds provide mostly UVA rays, and some experts believe that 15 to 30 minutes at a tanning salon are as dangerous as a day spent in the sun.
Sunscreens and Sunblocks.
Sunscreens and sunblocks, used generously, may help prevent skin aging and many skin cancers. Studies are conflicted, however, over whether sunscreens provide protection against melanoma, and some even question their value against more common skin cancers. In fact, there is some indication that they may encourage people --particularly those with fair skin -- to stay out in the sun too long and thereby actually increase the risks for melanoma. It should be noted, however, that people may not apply enough sunscreen and many of the studies showing little protection were conducted before the development of newer products with high sun protection factors (SPF50) (see Box below). The bottom line is not that people should avoid sunscreens but that they should always use them in combination with other sun-protective measures. Any sunscreens should contain a wide spectrum of UVA-blocking ingredients, which include butyl methoxydibenzoyl-methane (also called avobenzone or Parsol 1789), dioxybenzone, oxybenzone, sulisobenzone, methyl anthranilate, octocrylene, and octyl methoxycinnamate or ethylhexyl p-methoxycinnamate. Assuming the same ingredients are used, inexpensive products work as well as expensive ones. Sunscreen-containing shampoos, conditioners, and hair sprays are now available. Waterproof formulas last for about 40 minutes in the water, whereas water-resistant formulas last half as long. Sunblocks prevent nearly all UVA and UVB rays from reaching the skin, but to be fully protective they must contain zinc oxide or titanium dioxide. Standard sunblocks are white, pasty, and unattractive, but a new form of so-called microfine zinc oxide (Z-Cote) is transparent and nearly as protective as the older types. Zinc oxide, in any case, may be more beneficial than titanium oxide.
Calculating SPFs and Using Sunscreens
The SPF is an indexed number based on the amount of UV radiation required to turn sunscreen- or sunblock-treated skin red compared to non-treated skin. Sunscreens should not be used on babies younger than six months. Older children should apply sunscreen of at least SPF 4, with 15 being best. For adults, any sunscreen or sunblock used should have an SPF factor of 15 or higher; adults who rarely tan and burn easily should use SPF 20 to 30. Some experts recommend SPF 30 on the face and 15 on the body. Sunscreen or sunblock should be applied liberally 15 to 30 minutes before venturing outdoors and reapplied every two hours or so even on overcast days and especially after exercise or swimming.
Wearing sun-protective clothing is extremely important and protects even better than sunscreens. Everyone, including children, should wear hats with wide brims. (Even wearing a hat, however, may not be fully protective against skin cancers on the head and neck.) Clothing is being designed for blocking UV rays and is being rated using SPR ratings or the UPF (ultraviolet protection factor) index, with 50 UPF being the highest. People should look for loosely-fitted, unbleached, tightly woven fabrics. Washing clothes over and over improves UPF by drawing fabrics together during shrinkage. Clothing treated with a new compound called Rayosan increases the UPF rating of normal summer-weight cotton by 300%. Everyone over age one should wear sunglasses that block all UVA and UVB rays when in the sun.
A recent study found that dihydroxyacetone (Dt-IA), the active chemical in self-tanning lotions, is similar to melanin and may help filter out UVA and UVB radiation. More research is needed on this interesting finding.
Daily Preventive Skin Care
People are encouraged to wash their face with a mild soap that contains moisturizers. Alkaline soaps, especially with deodorant, should be avoided. The skin should be patted dry and immediately lubricated with a water-based moisturizer to prevent further dehydration. Hundreds of creams and lotions are available for wrinkle-protection, although very few have been proven to be very effective. Gentle scrubbing with a mildly abrasive material and a soap that contains salicylic acid can help remove old skin so that new skin can grow. Organic loofahs, sea sponges, and washcloths may harbor bacteria; nonorganic textured sponges do not carry this risk.
Some cleansing grains contain pulverized walnut shells and apricot seeds, which can lacerate skin on a microscopic level. Cleansing grains with microbeads don’t have sharp edges and remove skin without cutting it. It is very important to rub gently. The rubbing, which should be perpendicular to the wrinkle, mechanically removes the outer layer of dead skin cells and is particularly effective against tiny wrinkles that form around the mouth and eyes. Overall, the skin appears smoother and fresher. Exfoliation using scrubs, however, can worsen certain conditions, such as acne, sensitive skin, or broken blood vessels. No matter what product people put on their skin, it is important to include sunscreen with the daily skin regimen, even if someone is going outdoors for a short time.
Needless to say, the best long-term prevention for wrinkled skin is a healthy lifestyle with daily exercise to keep circulation moving, a diet with plenty of whole grains and fresh fruits and vegetables, and on-going methods for reducing stress and tension.