On Nutrition by Ed Blonz

WHY CHICKEN SOUP?

DEAR DR. BLONZ: Please provide some background about the use of chicken soup as a cold remedy. -- M.M., San Francisco

DEAR M.M.: Chicken soup has been used for generations, but a tradition can only go so far if it doesn't deliver. There is science here, but it will help to first understand what happens when you get a cold.

The immune system goes on the attack whenever it detects that a cold virus is attempting to take up residence in the upper respiratory system: the nose, sinuses and throat. A battle ensues, with one side effect being the inflammation that causes swelling of the mucous membranes lining the nose and throat.

At first, the immune system gets trounced, but over time, it learns to make the elements needed to squelch the invading virus. This can take hours, a few days, a week or longer, all depending on the tenacity of the virus and the state of your immune system. The "common cold" normally causes congestion, a runny nose, sore throat, a minor cough and a headache. If the virus persists and spreads down to the lungs, there is an increased risk of laryngitis (inflammation of the larynx/voice box), acute bronchitis and even pneumonia.

Stuffiness and discomfort are side effects, and they don't help the healing process. Congestion actually slows things down; if you rid yourself of the nasal secretions and mucus, you assist your immune system by allowing it to focus on making the weapons to win the battle. Blowing your nose is one obvious step, but care must be taken not to inadvertently force the bad stuff deeper into your sinuses (more info at tinyurl.com/pnfhjcn).

A group of physicians at Mount Sinai Hospital in Miami found that chicken soup was able to help clear the congestion that often accompanies a cold. This was discovered using a controlled experiment that measured the velocity with which mucus congestion was cleared through the nasal passageway. Dr. Irwin Ziment, a pulmonary specialist at the University of California at Los Angeles, attributed some of the soup's powers to the fact that chicken soup contains the amino acid cysteine, which is chemically similar to acetylcysteine, a prescription medicine used to combat congestion.

A cold is not the only instance where chicken soup can lend a hand: It can also help with asthma, where there is a narrowing in the bronchial tubes that carry the air in and out of the lungs. Coughing and mucus production can accompany the labored breathing of asthma, and one of the aims of therapy is to open up the airways and clear the lungs. Anything that helps move the mucus up and out of the body would certainly help.

Dr. Stephen Rennard at the University of Nebraska reported that chicken soup's effect might be due to its ability to block the inflammation and congestion caused by the movement of white blood cells (neutrophils) in the windpipe. In his experiment, the medicinal effect wasn't noticeable until the chicken soup was made with carrots, onions, sweet potatoes, turnips and parsnips.

Chicken soup doesn't have the same abilities as a modern antibiotic, but its powers are more wide-ranging, in a way: Antibiotics are only effective against bacterial infections, whereas soup can aid congestion brought on by either bacteria or viruses (like colds).

When thinking of making chicken soup, there are plentiful recipes to choose from. The basic recipe involves putting pieces of chicken (cooked or uncooked) into a large stock pot, then adding a couple of carrots, a large onion, a few stalks of celery, salt, pepper and enough water to cover. Then turn on the heat. Mimi Sheraton, in her book "The Whole World Loves Chicken Soup" (Warner 1995), supplies over 100 recipes from every corner of the globe.

With chicken soup, you get a satisfying, low-calorie dish that gives your body needed hydration and a potential vehicle for vegetables, protein and fiber. All this, along with an ability to help your body overcome that unwanted visitor. Not bad.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.