American Indians once used the brilliant purple cone flower to ease the sharpsting of snakebites. Today, Americans arm themselves with an extract of the plant, known as echinacea, to ease the sting of colds and flu.
Renowned for its ability to rev up the immune system, echinacea is native to the United States, although it is far more widely used in Europe. In Germany, for example, doctors write more than three million prescriptions for the herb each year, mostly to fight upper respiratory infections. Although it's not clear how it works, echinacea is believed to increase the number and efficiency of white blood cells, components of the immune system that battle infection.
The Journal of Family Practice reported in August that evidence supports taking echinacea several times a day at the first sign of sniffles to diminish the symptoms of an oncoming cold. A 1997 German study found that doing so ultimately made colds shorter and less severe, though research is less conclusive when it comes to taking echinacea to prevent an illness before it starts.
