Echinacea:

Our review last week of a study that found Echinacea ineffective for treating colds drove many of you to your keyboards to protest.

Several of you point out that the study was flawed, mainly because the research team used the wrong part of the plant for the trial. The root is the active part of the part, but the researchers used the leaves. The National Herbalists Association of Australia points out that the researchers used an extract of fresh juice, which is beneficial for building the immune system, but not fighting viral infections such as colds.

On this point, another reader says that these trials often use part of a herb in isolation. Side-effects can include a rash and tingle on the tongue, as the study reported. Used properly, she says, Echinacea provides some protection against colds and 'flu, if taken for 10 days each month but not continuously, and can shorten the length of the symptoms if taken every two hours at the onset.

Also, the quality off the product might play a part. Many examples on our shelves have been irradiated, fumigated, poorly processed and the like, which can affect the efficacy.

Anyway, this seems to restore Echinacea to its former glory, and again raises legitimate concerns that conventional medicine doesn't know how to properly test alternative products and therapies.