Many people take dietary supplements such as herbs in order to be well and stay healthy, according to the National Institutes of Health's National Center for Complementary and Alternative Medicine (NCCAM). A 2007 U.S. Centers for Disease Control and Prevention National Health statistics report says that nearly 20 percent of Americans indicated that they had used dietary supplements other than vitamins or minerals in the past year. Herbs might reduce your risk of getting influenza and decrease the severity of your symptoms if you do get sick. Discuss the use of herbs with your health care provider before taking them, especially if you have other kinds of medical problems.
Echinacea
A 2007 report in the journal "Alternative Medicine Reviews" states that echinacea is "arguably the most recognized herb for the prevention and treatment of colds and flu." In a randomized, double-blind trial of 150 adults who received an echinacea supplement or placebo, blood samples taken from the control group showed increases in the number of total white blood cells, monocytes, neutrophils and natural killers cells as compared to the placebo group. Taken orally, echinacea usually does not produce side effects, says NCCAM, with one exception. Since echinacea is a member of the daisy family, people who are allergic to daisies and related plants such as ragweed, chrysanthemums, marigolds, should not take this herb.
European Elder
The highly-regarded "German Commission E Monographs," which were translated into English by the American Botanical Society in 1998, endorse European elder (elderberry) as "effective relief for colds, fevers and catarrh," or excess respiratory tract secretions. Human cells infected with the influenza virus that are treated with preparations of European elder are not as capable of infecting other cells. European elder also stimulates phagocytes, specialized cells that attack and digest virus-infected cells. Two randomized, double-blind, placebo-controlled trials have demonstrated the effectiveness of the European elder extract Sambucol on infections due to influenza A and B strains. Given orally within 48 hours of symptoms onset, Sambucol produced complete symptom resolution in 13 out of 15 people after 3 days, compared to four out of 12 people who received the placebo. NCCAM recommends that only cooked, black or blue European elder (or supplements prepared from this) be consumed. Green or raw European elder may cause nausea, vomiting and severe diarrhea.
Astragalus
In a 2002 article in "Alternative Health Medicine," the authors explain that tonics made from Astragalus membranaceus are a centuries-old traditional Chinese remedy for both colds and flu. Data on Astragalus' efficacy against influenza are currently lacking, however, according to the NCCAM. Clinical trials are currently underway. In an experimental model of animals infected with Japanese encephalitis virus, supplementation with Astragalus root extracts boosted survival from 20 percent to between 30 and 40 percent, demonstrating the herb's effectiveness against other kinds of viruses. Astragalus is believed to be safe for most adults; however, organ transplant recipients and other people who take immunosuppressant drugs should consult their health care providers before taking Astragalus as it may interfere with the effectiveness of these drugs.
References
- CDC National Health Statistics Report No. 12; Complementary and Alternative Medicine Use Among Adults and Children; P.M. Barnes, B. Bloom, R. Nahin; 2007
- "Alternative Medicine Reviews"; Colds and Influenza; M. Roxas and J. Jurenka; 2007
- "Alternative Therapies in Health and Medicine"; Astragalus; D. McKenna, K. Hughes, K. Jones; 2002
