Sun 101: UV Exposure and Protection
Sun 101: UV Exposure and Protection
Understanding the Sun's Rays
The sun emits a broad spectrum of electromagnetc energy, including x-rays, gamma rays, infrared rays, cosmic rays, radio waves, ultraviolet light, and visible light. These waves irradiate toward the earth. Most are filtered out by the earth's atmosphere, including the most powerful ultraviolet wavelength, known as UVC. UVA and UVB, the other two UV wavelengths, do permeate the atmosphere and cause skin aging and skin cancer.
In recent years, research has demonstrated the important differences between UVA and UVB. UVB rays are shorter, more powerful rays that affect the epidermis (outer layer of skin) and are responsible for the sunburns we feel when our skin is unprotected. UVB rays tend to be more intense at higher altitudes and during summer months. Research shows repeated exposure to UVB rays can affect the immune system and lead to basal cell skin cancer, squamous cell carcinoma, and malignant melanoma, the most deadly form of skin cancer.
UVA rays, though longer than and not as powerful as UVB rays, are believed to penetrate more deeply into the skin, causing damage to collagen and cells that are in the dermis. Although some people might believe that tanning beds are a safer method of tanning, UVA rays are more prevalent and stronger in tanning beds than in natural sunlight. UVA rays cause skin tanning, age spots, and wrinkling of the skin, as well as contribute to the development of skin cancer.
Although direct sun exposure can cause irreparable damage, your skin is also exposed to UVA and UVB rays at home and at work on a daily basis. UVA rays can actually pass through windows in your home and cars. Both UVA and UVB rays can reflect off of sand, water, and pavement, exposing you to UV radiation even in the shade. In addition, some indoor office lightbulbs emit UVA and UVB rays, though at much lower levels than sunlight. The effects of such chronic exposure can be minimized with makeup and moisturizers that contain sunscreens.
UV Rays and Your Skin
The skin, while extremely effective at protecting the body from disease and invaders, is delicate enough to be damaged by the accumulation of daily UV exposure that we receive over a lifetime. When we are exposed to UVA and UVB radiation, whether from the sun or elsewhere, the body's defense mechanism attempts to protect the skin by triggering the production of pigment. Melanocytes, which are in the lower level of the skin, produce a pigment called melanin. Melanin granules collect together in little packages as melanosomes, which then migrate to the skin's surface as skin cells go through their natural process of sloughing off. This visible tan is evidence of skin damage. If you get sunburned, the UVB rays have penetrated the top layer of the skin, causing cellular damage. Sunburns, visible by redness, indicate that the body has increased blood flow to capillaries in order to try to repair the damage.
UV radiation causes the most damage through the creation of free radicals, which are known to disrupt the normal cellular process of our bodies. A free radical is a highly unstable molecule because it has an unpaired electron. To stabilize, free radicals scavenge other molecules for electrons to pair with their unpaired electrons. This begins a chain reaction that weakens cell function, damages cell structure, and can alter the genetic material (DNA) of a cell.
In this process, free radicals break down fibroblasts, which are responsible for collagen and elastin production. Collagen is a structural protein that gives the skin its strength and flexibility. When skin is damaged by UV rays, enzymes attempt to repair the affected collagen. If the damage is too extensive, the strands must be broken down and recycled to make new collagen. At the same time, UV radiation can cause the abnormal accumulation of elastin, another protein fiber that gives skin the ability to snap back into shape. Free radicals hinder cells' efficiency in producing these important skin proteins, permanently damaging the skin and causing photo aging in the form of wrinkles, sagging, dryness, and uneven tone.
Disease and Other Effects of UV Exposure
In addition to visible aging, overexposure to UV radiation can affect the body's immune system, limiting its resistance. When the skin is exposed to UV rays, certain chemicals are released that suppress the specialized cells that protect the body. Eyes are also susceptible to UV exposure, which may cause cataracts, macular degeneration, and, in rare cases, retinal damage caused by gazing directly at the sun.
Skin cancer, however, remains the most deadly consequence of UV exposure. When UVA and UVB rays interact with the skin, cells can mutate and form tumors. Basal cell and squamous cell skin cancers begin with this mutation deep in the dermis layer of the skin. Although basal cell cancer is the most common, it usually does not spread and usually is not fatal. With squamous cell cancer and keratocanthoma, both indicated by red, rough lesions, death is rare. Melanoma is the most deadly form of skin cancer, causing melanocytes in the skin, eyes, and mucous membranes to replicate uncontrollably into cells that are usually tan, brown, or black because of the melanin pigment. With early detection and treatment, melanoma can be cured. Most of the time, all of these forms of cancer could be prevented by protecting our skin from the sun.
Sunscreens are products that contain ingredients that either physically deflect UV rays away from the skin or chemically absorb UV rays. Physical sunscreens usually contain zinc oxide or titanium oxide in tiny particles that can deflect UV rays. For people with sensitive skin, physical sunscreens can be less irritating. Organic sunscreens contain chemicals (i.e., benzophenones, cinnamates) with molecules that absorb UV rays and convert the energy to heat, which protects the cells in the skin.
Sunscreens include a Sun Protection Factor (SPF), which describes the amount of protection a sunscreen provides from the UVB rays that cause sunburn. For example, if you would normally burn in the sun in 10 minutes, a sunscreen with SPF 15 allows you to be in the sun 15 times longer or, in other words, for 150 minutes without being burned. Most sunscreens are listed as SPF 15, SPF 30, or SPF 30+. Unfortunately, using SPF 30 or SPF 30+ does not necessarily double your protection from using an SPF 15. Some studies show that SPF can lead people to stay in the sun longer with a false sense of security, forgetting that UVA rays may also be damaging their skin. In addition, people often neglect to apply enough sunscreen to have adequate protection.
Because skin care experts have an increased understanding of the dangers of UVA rays, a new abbreviated term can appear on sunscreen labels to indicate a product's protection against UVA. The PA system consists of three grades: PA+ can protect sensitive skin against low to medium UV radiation, PA++ offers better protection from UVA that can be used by people with normal skin exposed to medium UV radiation, and PA+++—the strongest grade of UVA protection now available—is designed for normal skin under very strong or direct UV radiation.
Many entities involved in health research (the FDA, American Medical Association, American Academy of Dermatology, and the American Cancer Society) strongly recommend the use of sunscreens to minimize the effects of UV radiation. The FDA regulates sunscreens and their active ingredients as over-the-counter drugs to ensure that they are safe and effective in protecting against UV radiation. The following are ingredients that Nu Skin uses in its products to protect your skin from UV rays:
- Zinc oxide (micronized): A broad spectrum physical sunscreen that effectively blocks both UVA and UVB rays while helping control excess oil and shine. Micronization of the zinc reduces the white film usually associated with physical sunblocks.
- Parsol® 1789: A chemical ingredient that offers broad protection against UVA rays.
- Benzophenone-3: A chemical sunscreen agent that provides protection against UVA and UVB radiation.
- Octyl methoxycinnamate or ethylhexyl methoxycinnamate: A chemical sunscreen that helps to prevent sun damage by absorbing harmful UVB radiation.
- Octyl salicylate: A chemical molecule that helps to absorb UVB rays.
As research and knowledge about sun protection increase, the use of some ingredients has been discontinued. For example, PABA (para amino benzoic acid) is rarely used in sunscreen products anymore because it was found to irritate too many users and stain clothing. In place of PABA, Parsol 1789, oxybenxone, and octyl methoxycinnamate are used with the same effectiveness.
Nu Skin's Use of Sunscreens in Products
Nu Skin offers a variety of products, for everyday use as well as extended outdoor sun exposure, formulated to provide the skin with broad spectrum protection from UVA and UVB rays.
- Sunright® BodyBlock SPF 15 and 30, formulated with Parsol® 1789, provide broad spectrum protection against UVA and UVB radiation. Also contains SeaLastin® that protects collagen and elastin, licorice extract to soothe the skin, and antioxidants vitamins C and E to fight free radicals.
- Sunright® Lip Balm SPF 15 protects lips against UVA/UVB rays and cold weather chapping.
- Moisture Restore™ Day Protective Lotion SPF enhances the skin's natural resistance to the environment and contains UVA/UVB protection to help fight against aging caused by the sun. Available in two formulas, normal to dry and combination to oily.
- Nu Skin 180® UV Block Hydrator SPF 18 protects skin against the sun's UVA and UVB rays and diminishes past sun damage with DNA enzymes from sea plankton that mirror the skin's natural cellular recovery system.
- Tri-Phasic White® Day Milk Lotion is designed to moisturize and fight skin discoloration, to create a more even skin tone.
- MoisturShade® Liquid Finish Foundation SPF 15 provides radiant color and moisturizing, while protecting the skin with chemical UVA and UVB blockers.
- Skin Beneficial™ Tinted Moisturizer SPF 15 is a lightweight oil-free moisturizer that enhances natural skin tone with vitamins A and E and UVA/UVB sunscreens.
These products represent Nu Skin's efforts to incorporate sunscreens into both outdoor and everyday use products. As with other products, Nu Skin remains committed to monitoring research and honing formulations to ensure that sunscreens provide safe and effective protection from UV rays and counter the effects of aging.
Taking Care of Your Largest Organ—Your Skin
Although it can be difficult to balance the effects of UV exposure and the desire to be outdoors, there is one unified recommendation: to reduce the aging and negative effects of the sun, you must protect yourself from UV rays. Studies show that many people do not use sunscreens properly, either because they do not apply enough or do not reapply frequently. In any case, using products that provide sunscreen protection is only part of the defense.
- Use sunscreen with an SPF of at least 15, applying generously to all exposed areas at least 15 to 30 minutes prior to sun exposure. Even on cloudy days, apply sunscreen before going outside.
- Reapply sunscreen every two hours according to label directions and as needed, especially after swimming or sweating.
- Stay out of the sun during peak UV radiation exposure—between 10 a.m. and 4 p.m.
- Wear protective clothing, a hat that covers all of your face and neck, and sunglasses with UV protection.
- Protect children's skin with sunscreen, clothing, and limited exposure because many studies indicate that overexposure before the age of 20 may increase chances of skin cancers later in life.
- Do not use sunscreen that has expired because the ingredients can lose their effectiveness and decrease your protection.
- Apply sunscreen generously. Too many people under apply their sunscreen and, therefore, do not receive full sun protection.
Because people have different skin types and different levels of UV exposure, it is impossible to prescribe one kind of regimen to everyone, but most dermatologists will tell you that no sun exposure is good for you. Properly applying sunscreen and protecting your skin will keep you looking younger for longer.