Colds and Flu - the Good News!
Two research papers have demonstrated that Echinacea is effective in the prevention and treatment of colds and flu. The prestigious papers from the Cochrane Library and Clinical Therapeutics are in contrast to a spate of negative findings that had previously received widespread attention.
The first paper from the Cochrane Library investigated the use of Echinacea for preventing and treating the common cold(i). This is a review of 16 controlled clinical trials investigating the effectiveness of several different Echinacea preparations for preventing and treating the common cold. The key findings are:
- There is evidence that Echinacea can be effective for the early treatment of colds.
- Echinacea preparations differ appreciably in their composition, mainly due to the use of variable plant material, extraction methods and addition of other components.
- Products that are based on Echinacea purpurea and using the aerial parts of the plant are more likely to be effective.
The second paper was published in Clinical Therapeutics(ii). This research is a meta-analysis of the use of Echinacea in the prevention of induced rhinovirus colds in three studies. Each of these studies had produced seemingly negative results as they did not involve a sufficiently large number of patients, not because Echinacea is ineffective. Once all three are combined in a meta-analysis of 98 patients the results are both interesting and statistically significant. The conclusions drawn are:
- The risk of catching a cold increases by 55% in the absence of preventive treatment with Echinacea.
- Assuming that an adult catchesan average of two to four colds each winter, taking Echinacea as a prophylaxis can prevent one to two colds a year.
- If the bug does strike, it tends to be milder in people taking Echinacea than in placebo. Symptoms abate after just three to five days in people taking Echinacea to treat a cold; this is more than twice as effective as in those taking a placebo.
- Echinacea was seen as an effective prophylactic in cases of abnormally high infectiosity (high viral load).
(i) Linde K, Barrett B, Wolkart K, Bauer R, Melchart D Echinacea for preventing and treating the common cold. Cochrane Database of Systematic Reviews 2006 issue1
(ii) Schoop R, Klein P, Suter A, Johnston SL. Echinacea in the Prevention of Induced Rhinovirus Colds: A Meta-Analyses. Clinical Therapeutics. 2006; February (2)