According to fda.gov, people are advised to limit their time in the sun, especially 10 am-2 pm; wear clothing to cover skin exposed to the sun, such as long-sleeve shirts, pants, sunglasses and broad-brim hats; and use broad-spectrum sunscreens with an SPF value of 15 or higher regularly and as directed. Broad-spectrum sunscreens offer protection against ultraviolet (UV) rays—both UVA and UVB, two types of the sun’s UV radiation.
But how does the sun cause wrinkles? According to Hopkinsmedicine.org, UVB rays cause a much greater risk of skin cancer than UVA, but UVA rays cause aging, wrinkling and loss of elasticity. UVA rays also increase the damaging effects of UVB, including skin cancer and cataracts.
In most cases, UV rays react with melanin in the skin. This is the first defense against the sun and commonly results in skin darkening or tanning. A sunburn develops when the amount of UV damage exceeds the protection that the skin’s melanin can provide. A small amount of sun exposure is healthy and pleasurable, but too much can be dangerous. Measures should be taken to prevent overexposure to sunlight, such as those listed above.
The Cleveland Clinic offers detailed information on sun damage, or photoaging, which occurs when UV radiation from the sun penetrates the skin and alters it at a cellular and structural level. It breaks down essential structural proteins, mutates cellular DNA and causes pigment irregularities. UV rays (specifically UVA) penetrate deep into the dermis—the skin’s middle layer—where they trigger the production of free radicals. These free radicals damage the enzymes responsible for creating collagen and elastin. This degrades the structural network that keeps skin firm and tight, leading to premature sagging, fine lines and deep wrinkles. Both UVA and UVB rays directly penetrate skin cells and damage their genetic material (DNA). This damage alters the way cells grow and divide. When cellular DNA accumulates mutations faster than the body can repair them, it can lead to precancerous spots.
Common signs of sun-damaged skin include coarse wrinkles (deep lines and creases), leathery texture (thick, rough skin), sun spots, age spots and freckles, broken-appearing blood vessels (often on the face) and sagging or lax skin. Over time, this overproduction and clumping of melanin results in uneven skin tone, including freckles, age spots and melasma (hyperpigmentation). Sun exposure damages the skin’s local immune system and weakens the walls of small blood vessels. The result: impaired wound healing and a lowered ability to fight off cancerous cells. It also causes spider veins or broken capillaries on the face.
How much sunscreen should I use and how often should I apply it?
According to the American Academy of Dermatology, most adults need about one ounce of sunscreen—roughly the amount to fill a shot glass—to fully cover skin not covered by clothing.
When applying sunscreen to your face, use at least one teaspoon (about the amount needed to cover the length of your index and middle fingers).
Don’t forget to apply it to the tops of your feet, your neck, your ears and the top of your head.
Apply sunscreen to dry skin 15 minutes before going outdoors.
Skin cancer also can form on the lips. To protect your lips, apply a lip balm or lipstick that contains sunscreen with an SPF of 30 or higher.
When outdoors, reapply sunscreen approximately every two hours, after swimming or sweating, according to the directions on the bottle.
Skin types and sun tolerance
Sun tolerance times vary depending on skin type. Very fair skins may burn within 5–10 minutes, while olive or darker skins may tolerate sun for up to 40 minutes before damage occurs.
Darker skin has more melanin, which acts as natural sunscreen, but is still susceptible to skin cancer and premature aging.
Everyone should use broad-spectrum SPF daily to avoid photoaging. People with fair skin should use higher SPF (50+) and protective clothing, while those with olive to dark skin should focus on broad-spectrum protection.
How much sun should I get for vitamin D?
For most people, 10-30 minutes of direct sun exposure to the face, arms or legs twice a week is sufficient to maintain healthy vitamin D levels.
Getting a tan without sun exposure
To get a natural, sunless tan, use topical self-tanners (mousses, sprays, lotions) containing DHA, which darkens skin safely over several hours. For a more “inner-out” approach, consume foods high in beta-carotene (carrots and sweet potatoes) and dark-colored berries.
See you in the shade!
Lori Vance
Body Image Fitness, LLC
503.351.6476
Editor’s note: Wellness Word is an informational column which is not meant to replace a healthcare professional’s diagnosis, treatment or medication.