Herbs: Your Immune System's Best Friend
Herbal medicine has a centuries-old tradition of nurturing immune function — of keeping people healthy by treating them before they get sick — with an array of immunity-modulating and immunity-boosting plants.
One of the guiding principles of herbal medicine is the support of immune functioning through herbs known as adaptogens or tonics (see Chapter 2). Adaptogenic herbs help your body deal with the ill effects of stress — which can be caused by many things, including trauma, injury, or infection — without getting sick. Tonics are typically used to shore up a system that needs “toning” or “tonifying” (meaning it's failing or just performing below par).
Several herbs have demonstrated a direct effect on the immune system. Some, like barberry (Berberis vulgaris), echinacea (Echinacea purpurea), and goldenseal (Hydrastis canadensis), contain high concentrations of chemicals that increase immune system activity and thus are considered immunostimulants.
Exercise is a proven immunity booster. It flushes bacteria and other pathogens from the respiratory and urinary tracts (and skin, via sweat), increases circulation of antibodies and white blood cells, and slows the release of the stress-related hormones that can contribute to disease. Exercise even raises your body temperature, which acts like a fever to kill off infectious microbes.
Other herbs contain constituents that modulate the immune response, increasing immune activity when it's called for (i.e., when an infection is looming) and turning it down when necessary (in the case of allergies or autoimmune disorders). These are called immunomodulators, and they include astragalus (Astragalus membranaceus), Asian ginseng (Panax ginseng), licorice (Glycyrrhiza glabra), and reishi (Ganoderma lucidum); many of the herbs known as adaptogens are considered immunomodulators.