Echinacea Shortens the Course of the Common Cold


Echinacea Shortens the Course of the Common Cold

Reference: Hoheisel O, Sandberg M, Bertram S, et al. Echinagard treatment shortens the course of the common cold: a double-blind, placebo-controlled clinical trial. Eur J Clin Res 1997; 9:261-8.

Summary: A randomized, double-blind, single-center clinical study examined the effect of the expressed juice of Echinacea purpurea (Echinagard(*)) in patients with initial symptoms of an acute, uncomplicated upper airway infection (common cold). Patients were adults recruited from a large furniture factory in Sweden. Patients enrolled had suffered from at least three respiratory infections within the previous six months. Pregnant or lactating women, persons with systemic immunological diseases and those on immunotherapy, or persons with a history of hypersensitivity to plants of the Asteraceae family were excluded. Patients were randomized to receive either echinacea or placebo -- 20 drops in a half glass of water every two hours for the first day and thereafter three times daily for up to ten days. Patients recorded subjective symptoms and were interviewed by the attending physician about their symptoms and the course of illness. The primary variables were the number of patients reporting a "real" cold (fully expressed symptoms of the disease) and the time to improvement in each group.

One hundred twenty patients were enrolled and completed the study and all were included in the intention-to-treat (ITT) analysis. Fifty percent of the patients (24 in the echinacea group and 36 in the placebo group) reported experiencing a "real" cold. In the ITT analysis, the median time taken to achieve improvement was zero days with echinacea and five days in the placebo group (the time to improvement of zero days was assigned to all patients without a "real" cold). Analysis of time to improvement found that patients taking echinacea showed a more rapid recovery than those taking placebo (p < 0.0001).

In the subgroup of patients with a "real" cold, the median time to improvement was four days for the echinacea group versus eight for the placebo group. Patients with a "real" cold taking echinacea stopped treatment due to improvement after a median of six days compared to ten days for those on placebo. No specific adverse events were reported in either group.

Comments/Opinions: The findings of this study indicate that the use of an expressed juice of the aboveground parts of Echinacea purpurea, from the first signs of an upper respiratory tract infection, both inhibits the full expression of the infection and, when symptoms have developed, speeds up the recovery time. The study actually demonstrates the ability of echinacea to cut the duration of the common cold by almost half. Now that's an interesting public health message!

Effectively treating the common cold remains a challenge for modern medicine. Many cold and flu medicines aim at reducing congestion and fever as well as easing coughs. Unfortunately, in addition to side effects such as fatigue and decreased reaction time, these medicines may also prolong viral shedding and increase the duration of the disease.(1) Alternative therapies aimed at supporting the immune response such as echinacea and zinc actually shorten the duration of the illness while reducing risk of recurrence in persons with a history of recurring upper respiratory tract infections. As noted in my book, Herbal Prescriptions for Better Health (Prima Publishing, 1996), the use of echinacea extends to other recurrent infections such as otitis media and vulvovaginal candidiasis.

This study follows the successful results of Dr. Dom and colleagues using an extract of Echinacea pallida root in persons with acute upper respiratory tract infections (please see Dr. Reichert's review of this study in the Winter 1997 QRNM).(2) As was the case with the study reviewed above, both the length and severity of illness were reduced in persons taking echinacea. Interestingly, the current study found a somewhat greater decrease in duration of illness than the Dom study.

Two studies on echinacea for upper respiratory tract infections and the common cold await analysis and publication. The first, which was sent to me by David Schardt of the Center for Science in the Public Interest, is an unpublished study from Canada reporting on the efficacy of a standardized, encapsulated Echinacea angustifolia extract in college students with a common cold.(3) The study reports no efficacy for echinacea in shortening the duration or severity of the common cold when compared to placebo. Two immediate criticisms of this study are the choice of echinacea product and the fact that a higher dose wasn't used for the first 24 hours. The product used in this study is an encapsulated extract standardized to echinacosides. As opposed to the two products reviewed above, there are no clinical studies to support the efficacy of this product.

The second study is a six month, placebo-controlled trial testing the expressed juice of Echinacea purpurea (EchinaGuard(TM)) on incidence of respiratory tract infections in persons with a history of recurrent respiratory tract infections. This study, which is just being completed by Bastyr University, is not only well-controlled but also includes analysis of immunocompetence using the Multitest Merieux. The results of this study will be an important chapter in the determination of echinacea's efficacy.

(*) The brand name Echinagard is used in Sweden for the Echinacin(TM) product manufactured by Madaus AG of Cologne, Germany. It is sold in the U.S. under the brand names EchinaGuard(TM) and EchinaGuard(TM)Pro.

(1) Spector SL. The common cold: current therapy and natural history. J Allergy Clin Immunol 1995; 95:1133-8.

(2) Dorn M, Knick E, Lewith G. Placebo-controlled, double-blind study of Echinacea pallida radix in upper respiratory tract infections. Comp Ther Med 1997; 5:40-42.

(3) Galea S, Thacker K. Double-blind prospective trial investigating the effectiveness of a commonly prescribed herbal remedy in altering duration, severity and symptoms of the common cold. Unpublished, 1996.

Natural Product Research Consultants, Inc.


By D. Brown

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