Curative powers= According to food historians, chicken soup was already being prescribed as a cure for the common cold in Ancient Egypt. The 10th century Persian physician Avicenna also referred to the curative powers of chicken soup in his writings. In the 12th century the Jewish sage Maimonides wrote that chicken soup "has virtue in rectifying corrupted humours", and recommended it as nutrition for convalescents; Maimonides also particularly recommended chicken soup for people suffering from hemorrhoids and the early stages of leprosy. In modern medicine, research conducted by Dr. Stephen Rennard, professor of pulmonary and critical care medicine, and his colleagues at the University of Nebraska Medical Center in Omaha, suggests that there might be some scientific basis for the curative powers of chicken soup. They found that the particular blend of nutrients and vitamins in traditional chicken soup can slow the activity of certain white blood cells. This may have an anti-inflammatory effect that could hypothetically lead to temporary ease from symptoms of illness. Their research was published in 2000 in the scientific journal Chest (volume 118, pages 1150-1157: "Chicken Soup Inhibits Neutrophil Chemotaxis In Vitro")[1]. This was not, however, an in vivo clinical trial, and did not demonstrate that chicken soup was the best foodstuff for this purpose. Because it is simple to prepare, relatively cheap, nutritious, and easy on the digestive system, chicken soup is a good food for winter convalescents. Probably more significant, sipping warm soup can clear the sinuses because of the steam ventilating into the nasal passages, serving as a natural decongestant, which also relieves cold and flu symptoms. Last but not least, chicken soup can be beneficial due to the placebo effect of comfort foods. I got all this from Wikipedia: http://en.wikipedia.org/wiki/Chicken_soup

The steam from chicken soup may open up congested noses and throats. Soup also provides fluid, which is important for fighting infection. Some researchers suggest that substances in chicken soup reduce the inflammation associated with the common cold, thus providing some relief of symptoms.