6. Give herbs and algae a try
The herb ginseng has been shown to help prevent colds when taken as soon as symptoms develop. Researchers at the University of Western Ontario are conducting a study to determine what type of ginseng works, and how much.
Spirulina, a blue-green algae available at health food stores, is also promising. German researchers found that spirulina preparations containing zinc and powdered acerola (a vitamin C-rich tropical fruit) have high anti-inflammatory and antioxidant potential. Further testing is required to determine whether long-term use of spirulina preparations strengthens immune defense and reduces cold and flu risk. (Consult with a doctor or a trained practitioner before trying any dietary supplements.)