by Gabe Mirkin, M.D.
At last, the U.S. Food and Drug Administration (FDA) is proposing new rules on sunscreen safety. Finalizing these rules and actually making changes on the regulation or labeling of sunscreens will take time, so I advise you to follow their recommendations now by reading the labels and avoiding those products with ingredients that are unlikely to be safe or may be found unsafe.
Here are the proposed rules:
• Of the 16 active ingredients currently found in sunscreens, only two are “Generally Recognized As Safe (GRAS)”: zinc oxide and titanium dioxide.
• PABA and trolamine salicylate are unlikely to be safe.
• The other twelve active ingredients may not be safe. Among these, oxybenzone is an endocrine disruptor that may cause cancer and birth defects. The amount of these ingredients that is absorbed into the bloodstream is not known and has not been tested.
• Sunscreens that include insect repellents are considered not safe.
• The maximum proposed Sun Protection Factor (SPF) on sunscreen labels should be raised from SPF 50+ to SPF 60+. Using at least SPF 15 is recommended, but very high levels have not been shown to offer better sun protection.
• Consumer education should include other ways to protect skin from the sun: wearing protective clothing that covers the arms, torso and legs, wearing sunglasses and a hat that provides adequate shade to the whole head, and seeking shade when possible.
• The FDA has previously warned consumers not to use sunscreen pills; no pills or capsules prevent the sun from damaging your skin.
Problems with Sunscreen Ingredients
We do not know how safe sunscreens are because they have never been tested systematically. Oxybenzone in sunscreens has been shown to be absorbed into the bloodstream in humans and to disrupt hormones in animals. Many sunscreens contain the filters octylmethoxycinnamate, benzophenone-3 or octocrylene, which reflect ultra violet rays away from your skin to protect it only when they are on the surface of the skin.
However, when these sunscreens are absorbed and the skin is not re-coated, they increase skin production of harmful oxidants that can cause skin aging and cancer (Free Radical Biology & Medicine, September 2009). Reapplying the sunscreen so that some remains on the skin surface can help to prevent this damage.
Explanation of Sun Protection Factor (SPF)
The SPF on sunscreen labels tells you how long it takes to burn your skin underneath that sunscreen. It does not tell you how much protection you are getting. An SPF 30 sunscreen blocks 97 percent of UVB rays, compared to an SPF 15 sunscreen that blocks 93 percent. No sunscreen blocks all UV rays. There is no advantage to choosing sunscreens just because they have an SPF greater than 60. The FDA recommends that you do not need a sunscreen with an SPF greater than 30.
Broad-spectrum sunscreens provide some protection against UVA and UVB rays, but the SPF rating refers only to the level of protection from UVB rays. The FDA ruled that sunscreen labels that claim to be “broad spectrum” must protect against UVA as well as UVB.
These rules also prohibit any sunscreen from claiming that it prevents skin cancer or aging because no sunscreen blocks all UV rays. Sunscreens cannot claim that they last for more than two hours, unless proof of longer protection is submitted to the FDA.
What is Skin Cancer?
Every cell in your body is programmed to grow for a certain period and then die. This is called apoptosis. Skin cells live 28 days and then die. Red blood cells live 120 days and die, the cells in your mouth live 24 to 48 hours, and so forth. Cancer means that the cells do not die at their programmed time. The genetic material mutates (changes) and the cells try to live forever.
You replace your skin completely every 28 days. The outer layer of skin cells are constantly being removed as dander or dandruff. New skin cells start at the bottom inner layer of skin and move up toward the outside as you shed the old skin. The new skin cells are formed by reproducing the cells that contain your genetic material, DNA. The vast majority of skin cells continue on their normal 28-day path, but UV light can damage the genetic material so that some cells forget to die and become cancerous.
Everyone makes millions of cancer cells every day. One of the jobs of your immune system is to search out and kill cancer cells. A healthy immune system prevents most cancers from growing, but for various reasons which we do not fully understand, sometimes cancer cells escape destruction by your immune system and a cancer begins to grow in your body.
Most types of cancers do not kill a person until they spread to other parts of the body. For example, breast cancers do not kill as long as they remain in the breast. However, when breast cancer spreads to your brain, liver or lungs, it destroys these tissues, which can kill you. The same is true of skin cancers; they do not become deadly unless they spread to other tissues in your body.
How to Avoid Skin Cancer
Almost all skin cancers are caused by excessive exposure to sunlight and/or exposure to the sexually-transmitted virus called HPV. Basal and squamous cell skin cancers are caused primarily by cumulative exposure to sunlight over a lifetime, so every time you expose any part of your skin to direct sunlight for more than 10 minutes, you may be adding to the damage that you have received from previous exposures. Melanomas are different. They can be caused by a single sunburn at any age.
The most effective protection from UV light is a roof, and then clothes. Sunscreens are the least protective, but they are better than nothing. When you exercise outdoors, wear a hat that covers your ears and provides shade for your face and neck, and a long-sleeve shirt or a short-sleeve shirt plus arm coolers. Dark colored fabrics block UV rays better than light colors, and tightly woven fabrics block more UV than looser weaves. Hold the material up to a light source; the more light that passes through a fabric, the more UV will also pass.
Sunglasses block UV light and therefore help to prevent cancer in skin around your eyes. Skin cancers around the eyes, mouth, ears and nose are among the most difficult to treat and cure and are also the ones most likely to recur after treatment. Cancers in these areas can tunnel underneath the skin and not be obvious to the naked eye.
Sweating, swimming, or a single brush of your hand against your skin can remove any sunscreen. Apply a sunscreen so you can see it on your skin and then reapply that sunscreen at least every couple of hours.
Make sure that you apply sunscreen to the areas with the most exposure to sunlight over your lifetime: the top of your ears, your nose, your face, the back of your neck, and your arms and hands. To meet your daily vitamin D requirements from sunlight, you can expose your legs or other areas of your body that have received little cumulative sun exposure over your lifetime.
Most people cannot meet their needs for vitamin D unless they expose some skin to sunlight or take vitamin D supplements. Food sources are inadequate and vitamin D pills may not supply all the benefits of sunlight. People in southern climates can usually meet their vitamin D requirements by exposing just a few inches of skin for about 10 minutes at mid-day three times a week.
Sun Protection Myths
• Clouds do not protect you. Up to 80 percent of the sun’s UV rays can pass through clouds.
• Glass does not protect you completely. Glass blocks UVB rays that are the primary causes of skin cancer and sunburns, but they do not block UVA that can also cause skin cancer and aging.
• Beach umbrellas do not protect you as much as you might think. UV rays are reflected toward you from sand and water. Studies show that you get up to 84 percent of the exposure to UV radiation under an umbrella that you receive in the open sun.
• Dark skin does not protect you completely. People with darker skin still need to follow sun protection precautions. Skin pigment reduces the amount of UV rays that pass into skin, but it does not prevent sunburns or skin cancer.
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Gabe Mirkin, M.D., is a sports medicine doctor and fitness guru. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin has run more than 40 marathons and is now a serious tandem bike rider with his wife, Diana. His website is http://drmirkin.com/. Click to read Gabe's full bio.