As cold and flu season approaches, people will be looking for natural ways to prevent and treat these illnesses and their symptoms. Numerous rational options merit consideration for use, some of which are supported by a growing body of research. Here are some of the more compelling herbs for prevention or treatment of colds and flu.
American Ginseng (Panax quinquefolius) Extract Fraction (COLD-fX): American ginseng root, or its crude extracts, are not usually considered useful for treating cold symptoms. But that's not the case with a new proprietary Canadian product made from a special extract of this root. The extract, which just hit the U.S. market, is limited to the polysaccharide fraction of the American ginseng root, while most ginseng extracts are usually standardized to ginsenoside (saponin glycosides) and contain other compounds. Recent clinical trials have demonstrated this chemically defined product's ability to prevent and treat upper respiratory tract infections related to colds and flu. (See Nutrition Q&A)
Andrographis (Andrographis paniculata): Not to be confused with the controversial steroid hormone andro (androstenedione), andrographis is a traditional medicinal Ayurvedic and Chinese herb that is known for its bitter taste. At least seven controlled clinical trials on the Swedish product Kang Jang, a proprietary combination of andrographis and eleuthero (Eleutherococcus senticosus, formerly called Siberian ginseng), have been published during the past decade showing that the combination can help prevent and treat acute upper respiratory tract infections related to colds and flu.
Astragalus (Astragalus membranaceus): Astragalus root, huang qi in traditional Chinese medicine, is a staple in natural food stores because of its well-known immunomodulating effects. Despite increased popularity, there is a relative lack of published clinical trials on astragalus for use against colds and flu. Nevertheless, what research does exist strongly supports its consideration as a cold and flu treatment.
Echinacea (Echinacea angustifolia, E. pallida, E. purpurea): Various types of preparations from both the roots and tops of these species of echinacea are commonly sold. The clinical trial literature covers a wide range of preparations, testing a variety of clinical endpoints under numerous designs at varying dosages—with resulting confusion among health professionals as to how to interpret this body of research. For example, in a recent high-profile trial, the dosage of the three E. angustifolia root extract preparations was arguably about one-third the level recommended by the World Health Organization. The resulting negative publicity on this trial has had an adverse effect on consumer confidence in echinacea, which is still one of the most popular herbs sold in the United States. In a recent issue of the American Botanical Council's HerbalGram, University of Wisconsin medical professor Bruce Barrett, an echinacea expert, wrote that echinacea "remains a reasonable choice for prevention or treatment of the common cold."
Elderberry (Sambucus nigra, S. spp.): Elderberry has been the focus of scientific research in the past decade, with most of the studies conducted on Sambucol, an extract from Israel. Pharmacological and clinical trials have shown that elderberry exhibits antiviral activities and can reduce the severity and duration of flu symptoms on human test subjects. (For a comprehensive review, see the "ABC Clinical Guide to Elderberry" on ABC's Web site, www.herbalgram.org.)
A "cocktail" of these and other herbs can also be useful as a potential preventive or treatment for cold and flu symptoms, especially when taken at the initial signs of symptoms. For consumers preferring liquid herbal extracts, the relatively bitter taste of andrographis and the characteristic "tingling" taste of some echinacea root extracts can be masked by including these ingredients in a base of elderberry syrup, which offers not only a pleasant, fruity flavor but also functional immune benefits.
Mark Blumenthal is the founder and executive director of the Austin, Texas-based American Botanical Council. He edits HerbalGram, ABC's quarterly, peer-reviewed journal, and HerbClip, a twice-monthly science and clinical article summary service. He is also the senior editor of three reference books on herbal medicine.
Natural Foods Merchandiser volume XXVII/number 12/p. 35