Colds and influenza are the two conditions that affect us on a yearly basis. While a minor irritation for most people, these two conditions can pose a major health threat to the very young, the elderly, and those who are immunocompromised. In fact, the flu is a leading cause of death in the elderly. Americans spend over one billion dollars annually on nonprescription treatments for coughs and colds, including antipyretics, antihistamines, cough preparations, and decongestants in various combinations. Although these agents may help the symptoms of colds and flu to subside gradually, they do not address the underlying condition, including immune and nutrition status. Also, many of the agents used conventionally for colds and flu may cause unwanted side effects such as insomnia, hyper-excitability, dry mouth, constipation, drowsiness, or interact with prescription medications. There are several reasons for the recommendation of natural therapeutic agents as a first line of defense or as a complement to drug therapy. These reasons include:

• Pre-existing conditions or medications may preclude traditional OTC therapy;
• Occupation may eliminate the choice of antihistamines or decongestants (pilot, truck driver);
• Patient may request a natural product due to belief system;
• Flu vaccination may not provide adequate immune support.

The common cold, also known as upper respiratory infection (URI), is an acute, self-limiting illness caused by a virus. URIs cause absenteeism from work, accounting for 45 million days of restricted activity in 1996.(1) Preschoolers have the highest rate of infection, experiencing 6-10 episodes per year, while adults average 2-4 colds per year.(2)

Although viruses account for the overwhelming proportion of cases with about 30-50 percent being caused by rhinoviruses (rhino = nose) and 10-15 percent being caused by coronaviruses (corona = crown, 3) a secondary bacterial infection may also be present due to lowered immunity and stress on the system. Mechanisms of transmission of colds and influenza include aerosolization of virus-laden respiratory secretions and direct mucous membrane contact with virus from contaminated hands, other skin surfaces, and even furniture. Touching the eyes and nose with contaminated hands will increase transmission rates. There is current evidence that psychological stress can increase the risk and severity of viral infections.(4, 5)

Similarly, influenza is an acute respiratory illness that occurs in annual outbreaks of varying severity. The virus infects the respiratory tract and is highly contagious, producing systemic symptoms early in the illness. Influenza viruses belong to the family Orthomyxoviridae and are divided into three types (Types A, B, and C).Type C infection usually causes either a very mild respiratory illness or no symptoms at all; it does not cause epidemics and does not have the severe public health impact that influenza types A and B do. Efforts to control the impact of influenza are aimed at types A and B. Influenza viruses continually change over time, usually by mutation. Influenza is very contagious and is spread by contact with an infected person. A person is contagious from about two days before symptoms occur until about the fifth day of the illness.

No methods have been developed to effectively prevent colds and influenza to date. Vaccines are not likely to be effective in preventing the common cold, due to the large number of immuno-types and the lack of solid immunity to re-infection with the other viruses. Treatment of colds and influenza is largely symptomatic, with antibiotics not recommended for use in the therapy of uncomplicated colds and influenza due to the viral nature of the disease.

A recent resurgence in the use of nutrition