Echinacea, sometimes called purple cornflower, has been widely sold as an immune system booster and a natural treatment for colds. It's even recommended by the World Health Organization.
But according to USA Today, researchers at the University of Virginia School of Medicine found that the herbal remedy was no more effective than a placebo. The study tested the species of Echinacea originally used by Native Americans in the Midwest. 400 volunteers took either Echinacea or a placebo, and then were infected with a cold-virus to find out whether taking the herb prevented a cold, or shortened its duration. And the answer was a definite "NO".
Most of the previous tests on Echinacea were small studies, sponsored by supplement manufacturers. And the researchers say that since most colds get better after about 3 days, people might think it helps when it actually doesn't.
So if Echinacea doesn't work - what should you do to prevent a cold? Eat right, manage your stress, and get plenty of rest.