To Your Health
Is chicken soup as good for a cold or flu as people say it is?
A. Chicken soup has long been regarded in many cultures as a remedy for various ailments, especially upper respiratory infections. It seems that everybody has heard this from his or her mother or grandmother. Four years ago, research was published in the Oct. 17 issue of the medical journal CHEST verifying that chicken soup works well to relieve cold symptoms, though the active ingredient(s) remain somewhat of a mystery.
Some say the steam is the real benefit, and that sipping the hot soup and breathing in the steam helps clear up congestion. Others credit the love with which the soup is prepared and served. This may all be true as well, but the research demonstrates that chicken soup has anti-inflammatory properties. In particular, the movement of certain white cells called neutrophils was inhibited by something dissolved in the chicken soup. This may not "cure" the infection but does make a person more comfortable.
Neutrophils are our body's first line of defense against bacterial infections, but their presence also creates a good bit of discomfort. In fact, much of the damage done to our tissues by an infection can be blamed on the way the immune system uses neutrophils to attack invading bacteria. The "friendly fire" that takes out bacteria harms many of our own cells. The tissue damage from diphtheria, for instance, does not come as much from the diphtheria toxin as from the zeal with which the immune system defends us against the toxin. So slowing down the migration of neutrophils makes you more comfortable, though perhaps at the cost of slowing down your immune response.
Naturally there is some interest in isolating the active ingredient in chicken soup and marketing it. The researchers were not able to identify that ingredient. The soup used in the research consisted of chicken, onions, sweet potatoes, parsnips, turnips, carrots, celery, parsley, salt, and pepper. Researchers found that all the vegetables individually, as well as the complete soup containing the vegetables, had the ability to inhibit migration of neutrophils. It may be a combination of ingredients working together rather than a single ingredient doing all the work. There are many nourishing vegetables in the recipe with reputations for healing.
The meat ingredient of chicken soup, chicken, provides an amino acid (N-acetyl cysteine) known to thin mucus and make it easier to cough it up. Broth simmered only a short time is less effective than soup that has been on the stove for several hours, suggesting that it is necessary to break down the protein into its component amino acids for best results. This may also explain why many homemade soup recipes plus several supermarket brands all show the same effect to varying degrees.
One thing that seems clear: It is not the fat that provides the benefit. Traditional chicken soup has virtually all the fat skimmed off, and the fat-free commercial soup is still functional.
So if you go to your doctor for a flu shot and are advised to go home instead and make chicken soup, don't think you're getting an inferior treatment.