Eating grapefruits and other citrus food in advance of cold season is a simple immunity-booster in the West, but in traditional Ayurvedic medicine, a multitude of herbs, vitamins, minerals and proteins are mixed together to prevent and combat immune disorders. These combos, or tonics, are believed to help strengthen the body's defenses and to keep the appetite strong so illness has less of a chance of settling in.
Treatments for immunity are mixed depending on the condition or imbalance, but some general tonics can contribute to disease resistance when taken by healthy individuals.
One word of caution, though: Some ingredients have been found to be either toxic or dangerous when used in combination or along with traditional medications -- both prescribed and over-the-counter. Finding a reputable and trained Ayurvedic practitioner and eliminating any possible harmful drug interactions is very important before beginning treatments, even if they seem all-natural and harmless.