Many of my patients have come down with a nasty cold in the last two weeks – runny nose, cough, hoarseness, sore throat and the kind of fatigue that makes lifting your head off the pillow seem unnecessarily ambitious.  And just in time the Annals of Internal Medicine published a study to give them valuable advice. The effects of echinacea on the common cold have been studied many times previously, though never as rigorously as in this study.  A definitive benefit has never been proven. This st...