The Amazing Skin
With Quotes From Dr. Peter Elias, M.D.

The skin is vital to our well being. Thanks to techniques that allow researchers to cultivate and study living skin cells in a test tube, doctors have come to realize that the skin is a key factor in metabolic processes, as important in its own way as the liver and kidneys are in the active processing of medications, toxins, vitamins, enzymes and other substances.

The skin also appears to be an integral part of the immune system, helping the body ward off disease and dangerous chemicals. Dr. Peter Elias, head of dermatology at Veterans Administration hospitals in San Francisco and a professor of UC San Francisco says, "The outer layer of skin is by far the most metabolically active tissue of the body. It's a veritable enzyme factory."

Researchers are discovering that the skin's chemical defenses deal directly with invasive substances. When certain carcinogens enter the skin, they are attacked quickly by skin enzymes that render the invaders harmless.

The skin rarely, if ever, rests. "It is being assaulted all the time from the outside -- by ultraviolet light, excess oxygen, all sorts of dangerous chemical", Elias says. These threats require more than lipids, however. They must be met by a much more sophisticated chemical weaponry -- enzymes, essential proteins of the immune defense. Many of these enzymes are manufactured by the skin itself. "When the skin becomes stressed," he says, "as when it is attacked by solvents or detergents or is subjected to unusually low humidity, the factory begins to crank up." The stressed region is flooded with enzymes, which attack invading substances, until the threat passes.

But for all the protection the skin offers, it requires a measure of care that it does not always get. People often mistreat their skin, exposing themselves to excessive sun, neglecting growths with cancerous potential, and working in environments hostile to the skin.

Diet also can affect the health of the skin. While it has long been know that many foods can cause hives or skin rashes, now studies show that drinking alcohol, smoking and poor eating habits can provoke or worsen many skin conditions, including oral ulcers, a heightened sensitivity to sun and outbreaks of psoriasis an eczema. In addition, nutritional deficiencies in such trace elements as zinc, selenium and chromium have been linked to an increased susceptibility to skin cancer.

Researchers have found that the skin's so-called Langerhans cells are able to seize invading microorganism while calling upon the help of white blood cells know as T-cells to destroy them.

Other skin cells that work with the immune system -- and may be considered part of it -- are keratinocytes. As their name implies, they produce keratin, a family of tough, waterproof proteins that coat the body and are the basic component of hair and nails. But that's apparently not all they do. Scientists have found that these cells produce a hormone that stimulates the growth and development of T-cells -- the immune system cells that are the special target of the AIDS virus. Before this discovery, the production of T-cells was regarded as the exclusive responsibility of the thymus, a gland at the base of the neck that is crucial to the development of the immune system early in life.

The surprisingly versatile keratinocytes also produce a substance called interleukin-1, which in turn stimulates the T-cells into making a related substance called interleukin-2 -- a material that triggers the manufacture of special T-cells called helper cells. One of the helper cells' critical jobs is to mobilize still other components of the immune system to start churning out antibodies -- proteins specifically designed by the body to latch onto the outer surfaces of invading materials and neutralize or destroy them.

The skin also is also an eliminating organ. If the liver, kidney, spleen, and lymphatic system cannot eliminate all the toxins, the skin is the next organ that tries to get rid of the toxins. That is when we break out with pimples.