Winter is a wonderful time of year, filled with holidays, snow, and celebrations. Unfortunately, winter is also the peak of flu season - and this year it is supposed to be particularly harsh. While we await a cure, or at least a universal vaccine, research indicates that many foods are able to shorten the duration of a cold or the flu and alleviate symptoms. Many of them have long been touted as methods of alleviating symptoms, but new research indicates that many of these items actually help to fight infection in its tracks.

Chicken noodle soup has long been doled out as a method to alleviate the symptoms of a cold. However, a study published in the American Journal of Therapeutics found that carnosine, a compound found in many recipes for chicken soup, can indeed mobilize the immune system to fight the early stages of the flu. The research builds upon the findings of Dr. Stephen Rennard, a researcher from the University of Nebraska, who found that his wife's family chicken soup recipe helped inhibit the response of neutrophils, a type of white blood cells that defends the body against infection.

That inhibition appeared to reduce the symptoms of upper respiratory infection. Though Rennard could not identify the source of the soup's prowess, it was made up of carrots, celery, chicken, onions, parsley, parsnips, pepper, salt, sweet potatoes and turnips. For those of us without a family soup recipe, researchers also found that many commercial soups have a similar infection-fighting properties.

One study conducted in Miami studied the effects of cold water, hot water, and chicken soup on air flow and mucus. Among the 15 volunteers, researchers found that soup improved the function of cilia, the hair that lines the nostrils and prevents invaders from entering the body. However, hot water - an ingredient in tea - also helped to increase the movement of nasal mucus, clearing the airways and minimizing congestion.

Indeed, all of the ingredients in chicken soup may work together to fight infection. Organosulfides, found in carrots and onions, stimulates the production of macrophages, a type of immune cell. Vitamin C spurs production of the immune cells neutrophils and interferon. Carrots contain Vitamin A and carotenoids, which spurs antibody production. Vitamin E and zinc also enhances the amount of lymphocytes. Researchers have also found that the nutrients in liquids are more easily absorbed than when they are ingested in solid form.

However, if you do not like soup or do not have any on hand, do not despair. Many other foods contain some of the benefits of soup: teas, sweet potato, peppers, kiwi, and citrus fruits. Probiotics have also been found to help. In one study, people who took probiotics reported a 34 percent reduction in symptoms and had colds that lasted 48 hours less.