To Your Health
What can a person do to help prevent skin cancer?
A. Skin cancer is the most common cancer found in the United States. The incidence continues to rise, and DNA damage caused by ultraviolet light appears to be the most important single factor contributing to the development of skin cancer. Prevention of skin cancer using antioxidants and naturally occurring botanicals is one practical approach to this problem.
Human studies have convincingly demonstrated a protective effect of both natural and synthetic antioxidants when applied to skin prior to UV exposure. However, in order to be effective, a topical antioxidant must be in a form that is easily absorbed by the skin and have a proper pH (acid/alkaline balance). A mildly acid pH of 3.54.0 is generally the best for absorption. This is the natural pH of a lot of the "organic acids" found in botanical remedies.
Living organisms have two types of internal "space" requiring two types of antioxidants for complete protection. One is the watery area in and around cells, known as intracellular and extracellular fluid, and the other space is the oily membranes that serve as partitions, enclosing individual cells. Water-soluble antioxidants like vitamin C are effective mainly in the watery space, whereas fat-soluble antioxidants like coenzyme Q-10 mostly protect biological membranes. Both types of antioxidants are needed to create an effective shield against free radicals for the entire body, skin in particular.
There are many different antioxidants, available in a variety of skin products, which are potentially helpful. Alphalipoic acid, which is both water and fat soluble, and a substance known as dimethyl amino ethanol are particularly effective. Vitamin C ester (which is fat soluble), L-selenomethionine (a source of selenium), and lycopene (a carotenoid found in tomatoes) are among the other known nutrients that seem to help all sorts of skin problems when applied topically and taken orally.
Silymarin is a plant flavonoid isolated from the seeds of milk thistle. It is usually associated with the treatment of liver problems resulting from hepatitis or alcoholism. The same researcher who discovered that the polyphenols in green tea extract could help prevent skin cancer recently found that silymarin, in addition to its antioxidant effect, can prevent UV-induced skin cancers in animals (International Journal of Oncology, January 2005).
Even after skin is damaged by UV light, topical application of vitamin C, vitamin E, and selenium will actually prevent further damage and reduce the production of cancer-causing cells.
Both skin wrinkling and basal cell carcinoma (a skin cancer) are caused by sun exposure. Although it seems contradictory, people with very fair skin who sunburn easily and who also get lots of wrinkles tend not to get this form of skin cancer (see "To Your Health," April 8). Whatever is going on in the skin to produce wrinkles seems to be preventing the formation of basal cell carcinoma. More research will be needed to resolve this counterintuitive observation.