Zinc lozenges reduces the length of time cold sufferers have to endure sore throats, runny noses, sneezing, coughing and fever, according to a study published in the Annals of Internal Medicine by Wayne State University School of Medicine Professor Ananda Prasad.

Forty-eight patients who had colds participated in a random, double-blind study in which about half were give zinc lozenges while the other half received placebos to take every two to three hours while awake. Compared with the placebo group, the zinc group had shorter overall duration of cold symptoms - 4.5 days vs. 8.1 days. The lozenges particularly seemed to aid reducing coughing.

Dr. Prasad, a professor of hematology-oncology, is considered a world authority on zinc deficiency and its manifestations regarding human health. In 1963, while working to establish a university in Iran, Dr. Prasad met a 21-year-old man who looked like a 10-year-old. The man's symptoms, which included severe anemia, low iron and growth retardation, proved to be widespread. Commonly, people affected by the syndrome would die of pneumonia or parasitic diseases.

Although Dr. Prasad suspected these people had iron deficiencies due to poor diet, he wondered whether another metal deficiency would account for the growth retardation. He found it, and it was zinc. Studies already had shown that rabbits and mice lacking zinc experienced stunted growth. During the course of the 1960's, Dr. Prasad produced several studies, some of them now considered classic in the nutritional medicine field, showing that zinc supplements could counteract the syndrome.

He ended up proving that, at a cellular level, zinc is necessary to T cells, which battle all kinds of infection. Without zinc, the T cells don't function effectively, allowing potentially anything from the common cold to cancer invade the body. Dr. Prasad believes zinc and iron deficiencies occur in more than a billion people worldwide; one of Dr. Prasad's studies has shown one in four Detroiters to be zinc deficient.