News Feature: Natural-born killers

Abstract

Side effects: hepatitis, cirrhosis and liver failure Drug interactions: benzodiazepines Marketed for: depression and anxiety Side effects: stomach upset, sensitivity to sunlight Drug interactions: selective serotonin reuptake inhibitors,protease inhibitors Want a sharper mind, a slimmer body, a healthier heart or a longer life? You could find all that and more on the shelf of the nearest health-food store—if you believe the labels on dietary supplements, that is. Pink-and-purple ephedra capsules on the shelves extend the hope of effortless weight loss, pretty yellow flowers of St. John’s wort offer to lift your spirits and nondescript melatonin pills promise to lull you to sleep. If sales are any indication, the average consumer has firm faith in the power of supplements. There are nearly 30,000 herbal products on the market, totaling $4.2 billion of US sales in 2001. Of that, nearly $1.5 billion came from products containing—in some form—derivatives of ephedra, according to Patrick Rea, research director of the Nutrition Business Journal. In the UK, the complementary medicine market has grown by nearly 60% in the past five years, to an estimated £130 million. But can supplements deliver on their tall claims? “We don’t have a handle on how beneficial [herbal supplements] really are,” says David Schardt, senior nutritionist at the Center for Science in the Public Interest (CSPI), an advocacy group based in Washington, DC. For example, garlic has been shown to lower cholesterol levels, but only in the short term; ephedra has a small effect on weight loss,but studies have not evaluated its effects beyond a four-month period. Although there is little evidence of supplements’ benefits, several are known to have adverse effects. Kava kava, for example, sold as a stress reliever, has been linked to severe liver injury and is banned in several European countries, and St. John’s wort, touted as an antidepressant, interferes with birth control pills, HIV medications and drugs such as Prozac and protease inhibitors. Despite lack of evidence of their value, supplements have remained unregulated for years, thanks to the Dietary Supplement Health and Education Act (DSHEA) of 1994. The act places the burden of proof on the government, saying the US Food and Drug Administration (FDA) must show that a supplement causes “significant or unreasonable risk of illness” before it can be pulled from the market. In Europe,manufacturers must carry detailed files—including manufacturing procedures, N E W S F E AT U R E

DOI: 10.1038/nm0603-634

Cite this paper

@article{Mandavilli2003NewsFN, title={News Feature: Natural-born killers}, author={Apoorva Mandavilli}, journal={Nature Medicine}, year={2003}, volume={9}, pages={634-635} }