According to the National Institutes of Health National Center for Complementary and Alternative Medicine, interest in herbal supplements is increasing. In 2007, approximately 38 percent of U.S. adults reported using some form of complementary and alternative medicine, including herbal supplements. Three herbal supplements, in particular, have gained attention as potential remedies for flu symptoms.
Echinacea
According to a 2007 report in "Alternative Medicine Reviews," Echinacea is the most recognized herbal supplement for the prevention and treatment of flu symptoms. Two species of Echinacea, E. purpurea and E. Augustifolia, have been shown to activate cellular and humoral (antibody) immunity in both cultured cells (in vitro) and animals (in vivo). However, randomized clinical trials have shown mixed results, with some studies reporting a significant reduction in the severity and duration of symptoms in patients treated with Echinacea while others have failed to find a benefit. According to the National Institutes of Health's National Center for Complementary and Alternative Medicine (NCCAM), oral Echinacea rarely produces side effects. However, people with history of asthma or other allergies, especially to plants in the daisy family such as ragweed, chrysanthemums, marigolds and daisies, probably should not take Echinacea.
Elderberry
According to the same 2007 "Alternative Medicine Reviews" article, elderberry has also been shown to have direct and indirect benefits on flu symptoms. Elderberry-treated influenza-infected cells demonstrate diminished ability to infect other cells, compared to untreated cells. Elderberry also activates phagocytes, which are specialized cells that engulf and neutralize virus-infected cells. In clinical trials, elderberry appeared to reduce the duration of influenza symptoms from 7 to 8 days to 3 to 4 in treated individuals. NCCAM recommends that only cooked, ripe, black or blue elderberries be consumed. All others can cause nausea, vomiting and severe diarrhea.
Eleutherococcus senticosus and Andrographis patiiculata
A combination of Eleutherococcus senticosus and Andrographis patiiculata marketed under the proprietary name "Kan Jang" has been the subject of one of the largest clinical trials of herbal agents in the treatment of flu symptoms. In a 2003 study of 540 adults with influenza published in the journal "Herbal Pharmacotherapy," 30.1 percent of people treated with Kan Jang developed complications of influenza compared to 67.8 percent of people who received conventional treatment, including antiviral drugs. Patients in the Kan Jang groups also experienced a shorter duration of symptoms: 6 to 7 days compared with 9 to 10 days in the conventionally treated groups. As of January 2010, NCCAM did not list information on the safety or efficacy of Kan Jang or its component herbs.
References
- NCCAM: The Use of Complementary and Alternative Medicine in the United States
- Alternative Medicine Reviews; Colds and Influenza; M. Roxas and J. Jurenka; 2007
- Herbal Pharmacotherapy; A Randomized, Controlled Study of Kan Jang Versus Amantidine in the Treatment of Influenza in Volgograd; L.L. Kulichenko, L.V. Kireyeva, E.N. Malyshkina, and G. Wikman; March 2003
