Post by theshee on Jan 12, 2011 8:25:18 GMT 10
The herbal remedy echinacea, taken by millions to cure colds, does not work, US research has shown.
It found that cold sufferers taking echinacea were actually ill for longer than those who took dummy pills.
Many believe echinacea, which can be made into capsules, extracts, tinctures and tea, boosts the immune system.
The remedy is widely used to treat and prevent colds, but previous studies looking at its effectiveness have been inconclusive.
In the US study, 150 students who had recently developed colds were given echinacea or dummy pills - but were not told which group they were in.
A mixture of Echinacea purpurea herb and root and Echinacea angustifolia root was used in the trial.
Participants evaluated symptoms including cough, runny nose and sore throats daily.
No difference in severity of symptoms was found between those who took echinacea and those who did not.
On average, the colds of echinacea-takers lasted slightly longer - 6.27 days compared to 5.75 days amongst those on the dummy pills.
'Not the last word'
The research team, from the University of Wisconsin, wrote in the journal Annals of Internal Medicine: "We consider the results of this trial to be negative."
But they admitted that could be due to the specific preparation of echinacea they used, which could be different to other versions of the herbal remedy.
The team, headed by Dr Bruce Barrett, added: "Our results do not support a benefit of echinacea in the treatment of common cold symptoms."
But he said the trial should not be "the last word" on echinacea, and further research was needed.
In an editorial in the same journal, Professor Ronald Turner of the University of Virginia, said people buying echinacea were wasting their money.
"Nobody knows what echinacea's active ingredients are.
"Any expectation of benefit is based on faith rather than science.
"It's entirely possible to buy the same product over and over again and it actually has different levels of material in it."
news.bbc.co.uk/1/hi/2586207.stm
BACKGROUND: Echinacea is widely used to treat the common cold.
OBJECTIVE: To assess the potential benefits of echinacea as a treatment of common cold.
DESIGN: Randomized, controlled trial. (ClinicalTrials.gov registration number: NCT00065715)
SETTING: Dane County, Wisconsin.
PATIENTS: 719 patients, aged 12 to 80 years, with new-onset common cold.
INTERVENTION: Patients were assigned to 1 of 4 parallel groups: no pills, placebo pills (blinded), echinacea pills (blinded), or echinacea pills (unblinded, open-label). Echinacea groups received the equivalent of 10.2 g of dried echinacea root during the first 24 hours and 5.1 g during each of the next 4 days. Indistinguishable placebo tablets contained only inert ingredients.
MEASUREMENTS: The primary outcome was the area under the curve for global severity, with severity assessed twice daily by self-report using the Wisconsin Upper Respiratory Symptom Survey, short version. Secondary outcomes included interleukin-8 levels and neutrophil counts from nasal wash, assessed at intake and 2 days later.
RESULTS: Of the 719 patients enrolled, 713 completed the protocol. Mean age was 33.7 years, 64% were female, and 88% were white. Mean global severity was 236 and 258 for the blinded and unblinded echinacea groups, respectively; 264 for the blinded placebo group; and 286 for the no-pill group. A comparison of the 2 blinded groups showed a 28-point trend (95% CI, -69 to 13 points) toward benefit for echinacea (P = 0.089). Mean illness duration in the blinded and unblinded echinacea groups was 6.34 and 6.76 days, respectively, compared with 6.87 days in the blinded placebo group and 7.03 days in the no-pill group. A comparison of the blinded groups showed a nonsignificant 0.53-day (CI, -1.25 to 0.19 days) benefit (P = 0.075). Median change in interleukin-8 levels and neutrophil counts were also not statistically significant (30 ng/L and 1 cell/high-power field [hpf] in the no-pill group, 39 ng/L and 1 cell/hpf in the blinded placebo group, 58 ng/L and 2 cells/hpf in the blinded echinacea group, and 70 ng/L and 1 cell/hpf in the open-label echinacea group).
LIMITATION: Higher-than-expected variability limited power to detect small benefits.
CONCLUSION: Illness duration and severity were not statistically significant with echinacea compared with placebo. These results do not support the ability of this dose of the echinacea formulation to substantively change the course of the common cold.
www.ncbi.nlm.nih.gov/pubmed/21173411
It found that cold sufferers taking echinacea were actually ill for longer than those who took dummy pills.
Many believe echinacea, which can be made into capsules, extracts, tinctures and tea, boosts the immune system.
The remedy is widely used to treat and prevent colds, but previous studies looking at its effectiveness have been inconclusive.
In the US study, 150 students who had recently developed colds were given echinacea or dummy pills - but were not told which group they were in.
A mixture of Echinacea purpurea herb and root and Echinacea angustifolia root was used in the trial.
Participants evaluated symptoms including cough, runny nose and sore throats daily.
No difference in severity of symptoms was found between those who took echinacea and those who did not.
On average, the colds of echinacea-takers lasted slightly longer - 6.27 days compared to 5.75 days amongst those on the dummy pills.
'Not the last word'
The research team, from the University of Wisconsin, wrote in the journal Annals of Internal Medicine: "We consider the results of this trial to be negative."
But they admitted that could be due to the specific preparation of echinacea they used, which could be different to other versions of the herbal remedy.
The team, headed by Dr Bruce Barrett, added: "Our results do not support a benefit of echinacea in the treatment of common cold symptoms."
But he said the trial should not be "the last word" on echinacea, and further research was needed.
In an editorial in the same journal, Professor Ronald Turner of the University of Virginia, said people buying echinacea were wasting their money.
"Nobody knows what echinacea's active ingredients are.
"Any expectation of benefit is based on faith rather than science.
"It's entirely possible to buy the same product over and over again and it actually has different levels of material in it."
news.bbc.co.uk/1/hi/2586207.stm
BACKGROUND: Echinacea is widely used to treat the common cold.
OBJECTIVE: To assess the potential benefits of echinacea as a treatment of common cold.
DESIGN: Randomized, controlled trial. (ClinicalTrials.gov registration number: NCT00065715)
SETTING: Dane County, Wisconsin.
PATIENTS: 719 patients, aged 12 to 80 years, with new-onset common cold.
INTERVENTION: Patients were assigned to 1 of 4 parallel groups: no pills, placebo pills (blinded), echinacea pills (blinded), or echinacea pills (unblinded, open-label). Echinacea groups received the equivalent of 10.2 g of dried echinacea root during the first 24 hours and 5.1 g during each of the next 4 days. Indistinguishable placebo tablets contained only inert ingredients.
MEASUREMENTS: The primary outcome was the area under the curve for global severity, with severity assessed twice daily by self-report using the Wisconsin Upper Respiratory Symptom Survey, short version. Secondary outcomes included interleukin-8 levels and neutrophil counts from nasal wash, assessed at intake and 2 days later.
RESULTS: Of the 719 patients enrolled, 713 completed the protocol. Mean age was 33.7 years, 64% were female, and 88% were white. Mean global severity was 236 and 258 for the blinded and unblinded echinacea groups, respectively; 264 for the blinded placebo group; and 286 for the no-pill group. A comparison of the 2 blinded groups showed a 28-point trend (95% CI, -69 to 13 points) toward benefit for echinacea (P = 0.089). Mean illness duration in the blinded and unblinded echinacea groups was 6.34 and 6.76 days, respectively, compared with 6.87 days in the blinded placebo group and 7.03 days in the no-pill group. A comparison of the blinded groups showed a nonsignificant 0.53-day (CI, -1.25 to 0.19 days) benefit (P = 0.075). Median change in interleukin-8 levels and neutrophil counts were also not statistically significant (30 ng/L and 1 cell/high-power field [hpf] in the no-pill group, 39 ng/L and 1 cell/hpf in the blinded placebo group, 58 ng/L and 2 cells/hpf in the blinded echinacea group, and 70 ng/L and 1 cell/hpf in the open-label echinacea group).
LIMITATION: Higher-than-expected variability limited power to detect small benefits.
CONCLUSION: Illness duration and severity were not statistically significant with echinacea compared with placebo. These results do not support the ability of this dose of the echinacea formulation to substantively change the course of the common cold.
www.ncbi.nlm.nih.gov/pubmed/21173411