Perhaps our single most critical early defense system is the skin. Layered to provide an intricate web of barriers, the skin allows few pathogens to enter. Enzymes, complex proteins manufactured by the body that appear in body secretions such as sweat, provide additional protection, destroying microorganisms on skin surfaces by producing inhospitable pH levels. Normal body pH is 7.0, but enzymatic or biochemical changes may cause the body chemistry to become more acidic (pH of less than 7.0), or more alkaline (pH of more than 7.0). In either case, microorganisms that flourish at a selected pH will be weakened or destroyed as these changes occur. A third protection is our frequent slight elevations in body temperature, which create an inhospitable environment for many pathogens. Only when cracks or breaks occur in the skin can pathogens gain easy access to the body.The linings of the body provide yet another protection against pathogens. Mucous membranes in the respiratory tract and other linings of the body trap and engulf invading organisms. Cilia, hair-like projections in the lungs and respiratory tract, sweep unwanted invaders toward body openings, where they are expelled. Tears, nasal secretions, ear wax, and other secretions found at body entrances contain enzymes designed to destroy or neutralize invading pathogens. Finally, any invading organism that manages to breach these initial lines of defense faces a formidable specialized network of defenses thrown up by the immune system.*18/277/5*
Researchers have identified a number of substances in common foods that can help to ward off infectious illnesses. To maximize your resistance, include these foods in your daily diet: any member of the cabbage family—broccoli, cauliflower, mustard greens, kale, Brussels sprouts, and all forms of cabbage; garlic and onions; citrus fruits, berries, tomatoes, and peppers; and zinc-rich foods like wheat germ, whole grains, seafood, and meat.
DON’T SMOKE
Of course, this is a good idea even if preventing colds is not your concern. Smoking paralyzes the cilia, the tiny hairs that line the respiratory tract and are a first-line defense against infection. The cilia help to sweep out debris, including virus-contaminated mucus. Passive smoking, too, can increase your risk of infection. Infants and young children exposed to passive smoke are more likely to develop pneumonia and asthma.
REDUCE STRESS
Have you ever noticed that you’re most likely to come down with a cold when you’re about to leave on a trip or vacation, or when you’re rushing to meet a deadline, or when you’re cramming for a big exam? Dr. Sheldon Cohen, a psychologist at Carnegie-Mellon University in Pittsburgh, showed that people who test out as having the highest stress level are twice as likely to catch a cold as those on the lowest end of the stress continuum. So, relax! Try to reduce your stress level through regular exercise, meditation, yoga, T’ai chi, listening to relaxation tapes or sedating music, or any other harmless activity that can calm you down.
Learn to pace yourself. Keep balance in your life, allowing ample time for pleasure, regular aerobic exercise, relaxation, friends, fun, changes of scenery, and vacations from work or daily routines.
*13\296\2*