More evidence indicating efficacy of echinacea

[brettDbass]

http://news.independent.co.uk/health/article2705326.ece

"Echinacea is one of the most commonly used herbal products, but controversy exists about its benefits in the prevention and treatment of the common cold," according to the scientists, led by Craig Coleman of the University of Connecticut School of Pharmacy in Hartford, Connecticut.

"An analysis of the current evidence in the [scientific] literature suggests that echinacea has a benefit in decreasing the incidence and duration of the common cold," they say.

However, the researchers stopped short of recommending the prescription of echinacea to prevent or treat the common cold until further research based on larger-scale trials can show which doses and preparations are the most effective.

A good looking study, with a level-headed conclusion.

 

[Vitnir]

I thought the idea that echinacea had any benefit had been dismissed in scientific circles, I was baffled it was in Lancet this study had been published. I suppose we have to see what studies have been included to value this metaanalysis.

 

[CurtC]

Yeah, I saw that article and clicked on it, already suspecting that it would be a meta-analysis.

I had the impression that specific analyses had pretty solidly shown echinacea to not be effective, but admittedly I don't follow it that closely. Is my memory correct?

 

[Gord_in_Toronto]

From:
http://nccam.nih.gov/health/echinacea/
The official website of the National Center for Complementary and Alternative Medicine

What the Science Says

* Studies indicate that echinacea does not appear to prevent colds or other infections.
* Studies to date have not proven that echinacea shortens the course of colds or flu. For example, two NCCAM-funded studies did not find a benefit from echinacea, either as Echinacea purpurea fresh-pressed juice for treating colds in children, or as an unrefined mixture of Echinacea angustifolia root and Echinacea purpurea root and herb in adults. Other studies have shown that echinacea may be beneficial in treating upper respiratory infections.
* NCCAM is continuing to support the study of echinacea for the treatment of upper respiratory infections.

NCCAM -- dedicated to testing all the quack treatments one by one and showing no positive results but that "More research is required."

 

[Paul]

As was pointed out on the BBC this morning, even if the analysis proves correct, the complete lack of controls means that advising people to simply 'take echinacea' would be practically useless:

They found that more than 800 products containing echinacea were available, and that differing parts of the plant - flower, stem and root - were used in different products.

emphasis mine

 

[dakotajudo]

I had the impression that specific analyses had pretty solidly shown echinacea to not be effective, but admittedly I don't follow it that closely.

It's probably safer to say that *commercial* echinacea preparations are not effective.

But I may be biased; my thesis advisor is studying the ethnobotany echinacea and was doing some research on echinacea chemistry. See http://biomicro.sdstate.edu/nativeplants/uses/45-medicinal.html .

I've had a few conversations on herbology; not only with my advisor and fellow grad students (one was part of a failed commercial echinacea venture; he's now my main source of breeding and trial data from the winter wheat program); but also with one of the botanists in the biology dept. She's from China and a herbal user.

There are differences in the product, depending on when and where plant material is harvested. This is something that plant breeders work to standardize, but something the herbal industry doesn't seem to be interested with.

As I understand it, my friend's echinacea venture failed because it was cheaper for people to just harvest echinacea from the wild. The problem as I see it is that this harvest is done without consideration for the quality of material - just go too pasture and pull up roots. But herbalists don't harvest plant material haphazardly - there are some traditional methods of testing for quality. According to my Chinese contact, there are noticable differences in products obtained from Chinese herbalists versus those from commercial vendors.

In short, there may be great differences in the quality of commercial herbal preparations; enough that make interpreting the literature difficult.

Raw echinacea root has a taste and a tingle that is unique - and one I've not noticed in most commercial preparations. It's partly how to determine a good echinacea preparation, but also tends to make blinding difficult.

 

[axon]

Has anyone actually seen the study? I've had a look around and there's no mention of it on PubMed, the Lancet Infectious Diseases journal or on the authors website.

 

[fls]

Has anyone actually seen the study? I've had a look around and there's no mention of it on PubMed, the Lancet Infectious Diseases journal or on the authors website.

Here's the abstract.

(Just found it. Wasn't out yet earlier this morning.)

Linda

 

[Blue Wode]

Interesting to read what the following two scientists had to say about the study…

Dr. Wallace Sampson, editor of the Scientific Review of Alternative Medicine and an emeritus adjunct professor of medicine at Stanford University School of Medicine, said the methodologies of some of the studies used in the analysis were suspect, casting doubt on the pooled result.

Dr. Ronald Turner, a professor of pediatrics at the University of Virginia, who has studied echinacea in the past, called the report "a rehash of old data."
"It is a new interpretation, that's for sure, but I would rather see new data," he said.

-snip-

Coleman cautioned that the safety of echinacea hadn't been adequately studied and that no one should take the herb without first checking with a doctor. He said it was possible that it could interfere with the activity of some prescription drugs.

-snip-

Americans reduced spending on echinacea products by 16 percent last year, disillusioned about the herb's efficacy.

http://www.heraldnet.com/stories/07/06/25/100wir_a3colds001.cfm

…and yet here’s what a spokesperson for the herbal supplements industry had to say about it:

Dr Ann Walker, a director of the British Herbal Medicine Association, said: 'Traditional remedies attract a great deal of criticism so it's rewarding to see a scientific assessment that shows echinacea works, which is the reason for its continued popularity.'

She says that the herbal remedy has anti-inflammatory properties and is safe to use.

http://www.allaboutyou.com/news/home/newsstory/?News_StoryID=454448

Could this be the same Dr Ann Walker whose husband recently tried to have Professor David Colquhoun’s Improbable Science blog permanently removed from its server at University College London?

http://www.dcscience.net/improbable.html#walker1

 

[Vitnir]

I highly recommend Quackcast episode number 2 on this subject.
http://www.quackcast.com/QuackCast/Podcasts/Archive.html

 

[Eos of the Eons]

Here's the abstract.

(Just found it. Wasn't out yet earlier this morning.)

Linda

we did a meta-analysis evaluating the effect of echinacea on the incidence and duration of the common cold. 14 unique studies were included in the meta-analysis

I wonder which studies they compiled for these results?

Weighted averages and mean differences were calculated by a random-effects model (DerSimonian-Laird methodology)

Huh?

What does this mean? Some studies were done before, so some data was compiled from them, and the data compilers reached this conclusion. Soooo, their data trumps whose how?

Sachin A Shah PharmD a c,
Stephen Sander PharmD a c,
C Michael White PharmD a c,
Mike Rinaldi PharmD a b and
Dr Craig I Coleman PharmD a c

These are the guys credited with the data gathering report/study.

Gotta say, none of this looks convincing.

 

[Vitnir]

Since I'm not an epidemiologist, skimming through the article didnt enlighten me much. One of the heaviest studies was by Cohen 2004 in Arch Pediatr Adolesc Med that was looked into in a letter http://archpedi.ama-assn.org/cgi/content/full/158/3/222
The study had some limitations as a 25% dropout in the first week of treatment (same for treatment and placebo). Lack of demographic data on participants etc.
PM with email for a pdf-copy.

 

[athon]

Seems to be a rather interesting metastudy which has somewhat credible results.

The thing we have to keep in mind, though, is any sort of metastudy that has to look this hard to discover some results means the reliability of the material in producing an effect will be minimal. This is not the difference between life and death regarding cancer or influenza, but the slight improvement of coming down (or avoiding) a bloody head cold.

Could taking echinacea through the cold and flu season help? Seems to. Enough to spend that amount on the stuff? Not in my books. I'll stick to drinking lots of fluids and resting.

Athon

 

[Vitnir]

...
Could taking echinacea through the cold and flu season help? Seems to. Enough to spend that amount on the stuff? Not in my books. I'll stick to drinking lots of fluids and resting.

Athon

To top it off, even if you spent the money on the supplement you have no idea if you got what you paid for.

 

[Eos of the Eons]

Good point Vitnir,

A good study will take the active ingredient and standardize the dose. Those weeds in supplements could be any part of the plant, and most studies on the contents show no active ingredient to varying degrees of active ingredient.

http://www.emedmag.com/html/pre/cov/covers/031505.asp

With respect to product quality, a recent study of 11 echinacea products purchased over the counter showed that five products failed the minimal requirements for product purity and quantity of active ingredients. One brand failed due to excessive lead content and the other four due to inadequate levels of active ingredients.

In summary, recent studies have not helped to clarify the true effects of echinacea in the prevention or treatment of the common cold. The more modern studies that have been well designed have shown conflicting results. Currently under way is a clinical trial sponsored by the National Institutes of Health (NIH), expected to enroll 800 subjects and to be completed in 2006. Importantly, it is difficult to compare results of clinical trials of echinacea because of the variety of preparations used and the different clinical outcomes measured. Consistency of quality is a problem with echinacea, as well as other herbal and nutritional preparations, in the United States.

The study mentioned above found:

In this study, the research team found that none of three different preparations of the root of Echinacea angustifolia at 900 mg per day had significant effects on whether volunteers became infected with a cold virus, or on the severity or duration of symptoms among those who developed colds. http://nccam.nih.gov/news/newsletter/2006_winter/echinacea.htm

As well, we still don't know the study protocols of these 14 studies. Were they good sound studies? Any good studies I've come across with proper controls have shown no effects:

http://content.nejm.org/cgi/content/full/353/4/341

[FONT=Arial, Helvetica, sans-serif][SIZE=+2]An Evaluation of Echinacea angustifolia in Experimental Rhinovirus Infections[/SIZE][/FONT]
​

Results There were no statistically significant effects of the three echinacea extracts on rates of infection or severity of symptoms. Similarly, there were no significant effects of treatment on the volume of nasal secretions, on polymorphonuclear leukocyte or interleukin-8 concentrations in nasal-lavage specimens, or on quantitative-virus titer. Conclusions The results of this study indicate that extracts of E. angustifolia root, either alone or in combination, do not have clinically significant effects on infection with a rhinovirus or on the clinical illness that results from it.

http://www.turner-white.com/memberfile.php?PubCode=jcom_mar03_cold.pdf

Echnicea is not effective for treatment of the common cold

Non-antibiotic treatments for upper-respiratory tract infections (common cold)
Some studies (for non-antibiotic treatments) were statistically significant, but the Cochrane reviewers were guarded about how clinically significant they were. For Echinacea (in particular), problems were found with the quality of the studies and the wide range of different forms of this substance.


Conclusion Most non-antibiotic treatments for the common cold are probably not effective. The most promising are dextromethorphan, bisolvon and guiaphenesin for cough, antihistamine–decongestant combinations for a wide range of symptoms, nasal decongestants (at least for the first dose) and possibly zinc lozenges. ---note that echinacea is not mentioned

So, what were the 14 studies used in the article in the OP?

 

[Gord_in_Toronto]

<< SNIP >>

So, what were the 14 studies used in the article in the OP?

Fourteen with more positive results?

See. That was easy.

 

[Eos of the Eons]

Yeah, I'm thinking poorly done studies without controls? Why would the lancet host such a story?

 

[JJM]

Good point Vitnir,

A good study will take the active ingredient and standardize the dose. Those weeds in supplements could be any part of the plant, and most studies on the contents show no active ingredient to varying degrees of active ingredient.

http://www.emedmag.com/html/pre/cov/covers/031505.asp

With respect to product quality, a recent study of 11 echinacea products purchased over the counter showed that five products failed the minimal requirements for product purity and quantity of active ingredients. One brand failed due to excessive lead content and the other four due to inadequate levels of active ingredients. ...

{snip}

You are right, Eos, in calling for a study with known amounts of active ingredient. However, in the case of echinacea (and the vast majority of herbs), nobody knows what the active-ingredient (if any) is.

Pharmacognosists often assume a compound that is either unique to, or plentiful in, an herb is the "active ingredient." This is irrational. However, if they persist, the next step is clear- isolate that compound and test it.

 

[Vitnir]

The Cohen study is not easily exploded at a glance, but six out of nine of the studies on whether Echinacea has an ability to prevent infection are negative (confidence intervals include OR 1.0) but they are weighted much lighter than the Cohen study with its 0.136 OR.

 

[BlackKat]

An interesting observation:
The other day on the elevator at work the news screen on the elevator (http://www.captivate.com/) which displays brief news blurbs pulled from various newspapers showed a headline to the effect that a recent study showed the efficacy of echinacea at preventing or shortening colds. Subsequent research (performed right now) on a variety of major newspapers (New York Times, Boston Globe, The Guardian Unlimited, Chicago Tribune, LA Times, etc) Health sections provides no article at all. This leaves me wondering where Captivate pulled the headline from.

So is the Independent the only "major" newspaper to report this? Are they even reputable? I have heard the Independent derogatively refered to as one small step above a gossip magazine before but perhaps someone from Britain (who actually has read the newspaper before, unlike me) feels differently.

The reason I find this odd is that as useless as Captivate is for getting informed of newsworthy events it generally only reprints AP articles appearing in dozens if not more major newspapers.

But I am finding the article I did read from the OP's link in the Independent as suspect as the "study" the article is about.