New Paper Shows Echinacea Effective Against Colds
A study published in the July 2007 issue of the British journal The Lancet Infectious Diseases finds that the echinacea can help prevent a cold or reduce its duration.
A review of more than 700 studies has concluded that echinacea has a substantial effect in preventing colds and in limiting their duration. In fact, the research concluded that echinacea reduced the risk of catching a cold by 58 percent. It also found that the herb significantly shortened the duration of a cold by about a day and a half, but there was no general agreement about the magnitude of this effect.
The report which was published in the July issue of The Lancet Infectious Diseases analyzed the combined results of existing studies. The researchers selected studies that used randomized and placebo-controlled techniques: 14 studies involving 1,356 participants for the number of colds and 1,630 for the prevention of colds. The studies varied in the dosages of the herb, the duration it was taken and the species of echinacea used, and the number of participants ranged from 40 to more than 300.
Like many herbs, echinacea’s effectiveness in each case may have to do with which species and dosage is used. This helps explain why even a carefully devised single study might fail to show an effect that actually exists. Further more, there are more than 200 species of virus that cause colds. A study could test one species against which echinacea proves ineffective, while leaving open the question of whether it works for others.