Americans are obsessed with herbal supplements. A national survey conducted in 2007 found that almost 18 percent of the population uses some kind of herbal supplement, making this once niche industry a billion dollar mainstay. But although we often place our confidence and our cash in these bottles, what we’re actually getting is anyone’s guess. Unlike prescription and over-the-counter medicines, supplements do not go through safety or efficacy trials before they go to market and the claims on the front are often without warrant. Some herbs have been found to contain high levels of heavy metals, including lead and mercury. And some herbs, like ephedra, are dangerous on their own.
Despite the risks, we still spend the money. But should we? I looked at some of the popular herbs on the market to see what science says about their efficacy.
Echinacea
Echinacea is a plant whose parts are used, either fresh or dried, in everything from teas to pills. It is usually claimed to treat or prevent colds, flues, and to help the immune system.
There are conflicting results regarding whether Echinacea does what it claims. One of the best types of studies—a randomized, double-blind, placebo-controlled trial—looked at dried, encapsulated whole plant Echinacea in treating the common cold. Compared to a placebo, the authors of the study found that unrefined Echinacea provided no detectable benefit (or harm) in adults who had the cold. However, a meta-analysis, which looked at fourteen studies of Echinacea in the treatment and prevention of colds, found that it did shorten duration and had some effect in cold prevention.
According to the National Center for Complimentary and Alternative Medicine (NCCAM), a research organization run by the National Institutes of Health, most studies to date show that Echinacea does not appear to prevent colds or other infections. Research is still being done to determine what, if any, effects Echinacea has on the immune system.
Although Echinacea appears to be safe, some people have experienced allergic reactions to it, especially if they are prone to allergies from plants in the daisy family. People with autoimmune disease may also want to avoid the herb.
