Herbal Science Group says Dosages too Low in New Echinacea Trial

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All Messages Herbal Science Group Says Dosage Too Low in New Echinacea Trial

JoAnn Guest Aug 18, 2005 17:28 PDT

 

 

 

http://www.herbalgram.org/default.asp?c=echinacea072605

 

(Austin, TX, July 27, 2005). The nonprofit American Botanical Council

(ABC), an Austin, Texas-based research and education organization, has

reviewed a new clinical trial on the popular herb echinacea for use in a

specific kind of induced virus, being published Thursday in the New

England Journal of Medicine

 

The study concluded that the echinacea preparations did not prevent or

help treat symptoms of a specific virus applied to the test subjects.

 

ABC has found several aspects of the design of the study worthy of

clarification, and comments on the potential misinterpretations of the

significance of this study.

 

First, the extracts used were made in a university laboratory and do not

" correlate " with commercial echinacea products currently available to

consumers.

 

Second, the dosages used in this trial were probably too low.

 

The echinacea preparations used in the study might have shown activity

at more frequent dosing intervals and/or higher dosage levels – as is

often the case with contemporary echinacea use.

 

The new trial utilized extracts made from the roots of a species of

echinacea called Echinacea angustifolia. The randomized, double-blind,

placebo-controlled, seven-arm trial was conducted on 437 college

students who had a particular type of rhinovirus inserted into their

nostrils (the results were calculated on 399 subjects).

 

In the trial, the echinacea preparations were tested to see if they had

a preventive effect or if they could help treat the symptoms caused by

the rhinovirus.

 

The students who received the three different echinacea preparations and

were sequestered in a hotel room did not experience fewer infections,

fewer symptoms, or a reduction in the duration of symptoms, compared

with those who received the placebo.

 

The trial utilized three doses of 1.5 milliliters each of the three

laboratory-produced echinacea extracts, presumably equivalent to about

300 milligrams of the dried powdered root in each dose (equivalent to

900 mg per day of the dried root).

 

This level was chosen for the trial because it is the dose recommended

by the German government’s expert herb panel called the Commission E,

which had conducted reviews of the research published on various types

of echinacea in the scientific and medical literature in the early

1990s.2

 

According to ABC various international monographs have acknowledged the

generally higher dose used for echinacea root products.

 

The World Health Organization (WHO) monograph for Echinacea root

(“Radix Echniaceae”) has a dosage for Echinacea angustifolia root at the

equivalence of 3 gm per day of the dried root.3

 

This same dosage is also acknowledged in the more recently developed

draft monographs on Echinacea from the Canadian Natural Health Productsate.4

 

This dosage level is about 330% higher than the dosage of the echinacea

preparations given in the NEJM trial.

 

This supports ABC’s contention that the preparations may have been

under-dosed and that the trial might have shown a potentially positive

trend if a higher dosage and/or increased frequency of administration

had been followed.

 

“It would have been optimal if this trial had tested the echinacea

preparations at more frequent and/or higher doses,” said Mark

Blumenthal, Founder and Executive Director of ABC.

 

“Dosage is one of the most important aspects in assessing any

therapeutic agent.

 

Many clinicians who recommend echinacea for treatment of upper

respiratory tract infections related to colds and flu normally utilize a

frequency of use and/or a total daily dose that is higher than the one

used in this trial.

 

This is also true for consumer self-medication with many commercial

echinacea preparations according to some label dosage suggestions.”

 

Blumenthal added. “The researchers have previous experience in

researching echinacea and have done an admirable job in testing a

species of echinacea (i.e., E. angustifolia) that has not been

adequately researched.”

 

But he hastened to add, “The most accurate statement that can be said

about this trial is this:

 

These specific laboratory-produced echinacea extracts, at the dose given

in the trial, under the specific design of this trial, did not produce

any measurable effect.”

 

He emphasized, “This is not a definitive trial on the efficacy of

echinacea, nor should the results be generalized to echinacea

preparations widely available.

 

Unfortunately, the conclusion that may be drawn by some media who report

this study may state that ‘echinacea is ineffective,’

but this would be an incorrect conclusion based on the design of this

study and the evidence in the existing literature.”

 

“Dosing people for rhinovirus in a hotel does not necessarily mimic real

life,” said Bruce Barrett, MD, PhD, an Assistant Professor of Family

Medicine University of Wisconsin School of Medicine and an author of

several previous critical reviews on echinacea clinical trials.

 

He noted that the patients were possibly relatively resistant to the

echinacea treatment.

 

“College kids are immunocompetent,” he stated, referring to the relative

health of the test subjects in the trial. “It may have been better to

test older people to see how they might have faired.”

 

However, Dr. Barrett was generally complimentary about the trial in

general. “This is a very valuable study and quite helpful, although it

has some significant limitations, including product, sample, and

population,” he stated.

 

“In general, you may want to have about 100 people per treatment group

for more statistical significance rather than only about 50 per group

used in this trial.”

 

In general, products marketed as “Echinacea” are extremely popular in

the United States. Echinacea ranked second in sales in mainstream market

retail stores in 2004, according to an article in ABC’s journal

HerbalGram.5

 

Total sales of echinacea products in all channels of trade in the United

States in 2004 was estimated at about $155 million, according to data

compiled by Nutrition Business Journal.

 

Blumenthal also added that although it was formerly quite popular, there

has been a trend away from using Echinacea angustifolia root in

commercial herbal products based on increased concerns by many

responsible members of the herb community regarding conservation and

sustainability of wild medicinal plants.

 

Echinacea angustifolia is generally more difficult to cultivate

commercially than the other two more popular species of echinacea (E.

pallida and E. purpurea), and so more material from these species are

found in products on the North American market.

 

Blumenthal points to a body of clinical evidence that supports the use

of various echinacea preparations for treating symptoms associated with

colds and flus.

 

A therapeutic monograph on Echinacea is available in The ABC Clinical

Guide to Herbs, ABC’s reference book and continuing medical education

module.6

 

The monograph summarizes 21 clinical trials on various echinacea

preparations for colds, flus, upper respiratory tract infections, and

other uses.

 

ABC has posted the complete echinacea chapter including this monograph

on its website as an educational service to the public.

 

The study has generated significant media attention. ABC and Blumenthal

have been contacted by a variety of news sources, including: the

Associated Press, Bloomberg Business News, CNN, the Los Angeles Times,

NBC Nightly News with Brian Williams, the New York Times and USA Today.

 

About the American Botanical Council

 

The American Botanical Council is the nation's leading nonprofit

organization addressing research and educational issues regarding herbs

and medicinal plants.

 

The 17-year-old organization occupies a 2.5 acre site in Austin, Texas,

where it publishes HerbalGram , a peer-reviewed journal. ABC is also the

publisher of The ABC Clinical Guide to Herbs, a continuing education and

reference book, which contains extensive monographs on the safety and

efficacy of 29 popular herbs, including echinacea.6

 

More information on echinacea is available on ABC’s extensive website,

http://www.herbalgram.org/.

 

 

References

 

1. Turner RB, Bauer R, Woelkart K, Hulsey TC, Gangemi DJ. An evaluation

of Echinacea angustifolia preparations in experimental rhinovirus

infections. N Engl J Med 2005;353:341-348.

 

2. Blumenthal M, Busse WR, Goldberg A, Hall T, Riggins CW, Rister RS,

eds. Klein S, Rister RS, trans. The Complete German Commission E

Monographs – Therapeutic Guide to Herbal Medicines. Boston: Integrative

Medicine Communications; Austin, TX: American Botanical Council, 1998.

 

3. Echinacea Radix. In: WHO monographs on selected medicinal plants.

Geneva: World Health Organization, 1999.

 

4. Ehinacea. Natural Health Products Directorate. Health Canada. Draft

Jan 2004. Available at:

http://www.hc-sc.gc.ca/hpfb-dgpsa/nhpd-dpsn/mono_echinacea_e.pdf

Accessed, Jul 27, 2005.

 

5. Blumenthal M. Herb sales down 7.4 percent in mainstream market.

HerbalGram 2005;66:63.

 

6. Echinacea. In: Blumenthal M, Hall T, Goldberg A, Kunz T, Dinda K,

Brinckmann J, et al, eds. The ABC Clinical Guide to Herbs. Austin, TX:

American Botanical Council, 2003.

 

 

 

 

 

 

 

American Botanical Council, 6200 Manor Rd, Austin, TX 78723

Phone: (512) 926-4900 | Fax: (512) 926-2345 | Email: ab-

 

American Botanical Council, 6200 Manor Rd, Austin, TX 78723

Phone: 512-926-4900 | Fax: 512-926-2345 | Email: ab-

 

 

JoAnn Guest

mrsjo-

www.geocities.com/mrsjoguest/Diets

 

 

 

 

AIM Barleygreen

" Wisdom of the Past, Food of the Future "

 

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