The safety and efficacy of kava, ephedra, and St. John's wort have recently come under dispute. Do these popular herbs deserve the bad rap they get?
By Gargi Talukder, PhD
Seems like every time you pick up a newspaper or a magazine, you see another report on the dangers of using certain herbs. "Popular Herb May Severely Harm Liver" was a 2002 headline in the San Francisco Chronicle, referring to kava. "St. John's Wort Ineffective," wrote editors at the Washington Post in 2001. "Side Effects Raise Flag on Dangers of Ephedra" was the banner in the New York Times. Recent media attention has focused on research projects that highlight the dangerous side effects or ineffectiveness of these herbal supplements. But many researchers and medical professionals still believe these herbs, when used correctly, produce benefits with little risk of harm. We've taken a closer look at kava, ephedra, and St. John's wort to help you sort through the confusion and make the best choices about whether to use them.
Kava (Piper methysticum)
The claim: Kava causes extensive liver damage.
The truth: Kava has been shown to cause extensive liver damage only when taken in quantities much larger than the recommended amount.
In March 2002, the Food and Drug Administration (FDA) issued a consumer advisory warning that kava, an herb used by many to relieve stress, anxiety, sleeplessness, and menopausal symptoms, can cause severe liver injury, including hepatitis, cirrhosis, and liver failure. The advisory stated: "Although liver damage appears to be rare, the FDA believes consumers should be informed of this potential risk." Such a pronouncement from an agency that safeguards the public's welfare was understandably received with concern. Most of the newspaper and magazine articles that soon appeared simply reiterated the warning, leaving out background information on what spurred the FDA's advisory in the first place.
For example, buried in the news coverage of the kava advisory—if mentioned at all—was the fact that the number of reported cases of liver damage possibly due to kava was low. And of the 25 cases reported by people taking kava in Europe, many involved people who had liver damage prior to using kava or who used alcohol, a substance known to harm the liver. "These were a very small group of reports, and there was very little evidence that there was a direct link between liver toxicity and kava," says Phil Harvey, PhD, chief science officer with the National Nutritional Foods Association (NNFA). "Many of the individuals were taking other medications at the same time, and these other medications may have actually been the cause of the liver toxicity."
The first reaction should not be to ban kava but to study it and really understand what's going on with the way the body processes it. Subsequently, the sale of kava has been restricted or banned in several European countries, and the FDA is now in the process of examining some 38 cases of possible kava-related liver damage in the United States, though the number changes weekly. Among the U.S. reports filed are one about a woman who took up to 15 kava pills daily (well above the product's recommended dosage) in addition to prescription medications and one about a 13-year-old who deliberately took an overdose of kava.
After the FDA issued its advisory, a number of herbal products trade groups, including the American Herbal Products Association, the National Nutritional Foods Association, and the American Botanical Council, commissioned a University of Illinois researcher to investigate these reports of adverse effects from kava filed in the years 1998 to 2001. The researcher, Donald Waller, PhD, professor of pharmacology and toxicology in the department of pharmaceutics and pharmacodynamics at the University of Illinois at Chicago's College of Pharmacy, found "no clear evidence that the liver damage reported in the U.S. and Europe was caused by the consumption of kava." Many of the reports involved people who were taking large amounts of the herb (the American Herbal Products Association recommends doses not exceeding 300 mg of total kavalactones or kavapyrones, the active compound in kava, per day) or who were taking other medications or supplements, or were consuming alcohol.
One month after Waller submitted his report to the FDA, the agency responded with another consumer advisory that essentially repeated Waller's findings, concluding with a message that the FDA would further investigate kava's risks. "The agency will alert consumers, and if warranted, take additional action as more information becomes available" was the FDA's official announcement. Thus far, the FDA has issued no further warnings on the potential harms posed by this herb.
Here are some Web sites to visit for more details on the safety of herbal remedies.
The Food and Drug Administration (FDA) site for dietary supplements
American Herbal Products Association
National Nutritional Foods Association
American Botanical Council
Council for Responsible Nutrition
Ephedra Education Council
The main concern regarding kava appears to be the danger of taking too much, which, as with any other drug, can be harmful. Research trials that have found no adverse effects of kava generally prescribe 120 mg of kavapyrones per day. Batavia, Illinois-based chiropractor Mathew Hajzl, DC, publisher of a newsletter on natural remedies and who uses both traditional and pharmaceutical remedies to relieve muscular and skeletal pain in his patients, has found the 120-mg dose to be beneficial and has not seen any liver toxicity in his patients. Hajzl also says up to 500 mg per day should be fine when carefully monitored by a physician. "It's still hard to make a statement about kava and its potential harms," Hajzl says, "because its actions are complicated, and each person is going to respond to it a little differently. But this is true of all drugs." That's why Hajzl says it's crucial to talk with your doctor before starting any herbal regimen and tell him or her about any other supplements or prescriptions you are taking. You also need to stick to recommended doses. "I know not everyone wants to do this," he says, "but it really is the best way to know that you are being as safe as possible."
Many experts applaud the FDA's actions so far. "I think the FDA is doing the right thing by warning consumers about the drug," says Chun-Su Yuan, MD, of the University of Chicago, an anesthesiologist who has studied the sleep-inducing effects of valerian on humans and of kava on animals. "They haven't jerked the products off the shelf yet; they are waiting for detailed reports. The FDA wants to be careful, and they are waiting for some real evidence before they make a strong move for or against it."
Harvey echoes this sentiment, adding, "It is possible that individuals taking certain medications should not take kava, but that doesn't mean kava is a bad supplement. The first reaction should not be to ban it, but to study it and really understand what's going on with the way the body processes it."
The bottom line? If you have liver problems or take medications that affect your liver, or if you drink alcohol regularly, speak with a doctor before taking kava. The American Botanical Council, a nonprofit education and research organization, also recommends that people avoid taking kava on a daily basis for more than four weeks in a row. And as with any herb, follow the recommended dosages.
Ephedra (Ephedra sinica)
The claim: Ephedra is a dangerous weight-loss herb that causes high blood pressure, stroke, and heart attack.
The truth When taken in recommended doses, ephedra is considered to be safe.
The market is flooded with ephedra products, stemming in large part from the herb's much-touted reputation as a weight loss wonder drug. But on Oct. 8, 2002, the American Medical Association (AMA) offered testimony on ephedra's dangerous effects to Congress, urging legislators to remove dietary supplements containing ephedra from supermarket shelves. The AMA's request came after several high-publicity ephedra-related deaths, among them the deaths of three college and pro football players in 2001, including Minnesota Vikings tackle Korey Stringer. Although investigators found no evidence of stimulants in Stringer's body, an empty bottle of an ephedra-based product was found in his locker, leading many to point to ephedra as the cause of his death. Following these incidents, ephedra was banned from the Olympics, the NFL, and college sports. After so many sports organizations have taken action—and so many health incidents have been tied to this energy-boosting herb—the AMA's urge to ban ephedra seems more than warranted by some, but to others it seems a reactionary move based on few facts.
Politicians and the media are relentless in trying to find the negative in ephedra. To understand the argument, it helps to know how ephedra works as a weight loss drug. One effect of ephedra is its thermogenicity, or ability to produce heat. This changes the body's metabolism, speeding the way fuel is used, which can result in weight loss. In an attempt to take advantage of ephedra's promotion of weight loss, some people have taken large quantities based on a more-is-better philosophy (the industry-recommended dose is no more than 25 mg ephedrine alkaloids per serving and no more than 100 mg total per day). Large amounts of ephedra may lead to serious consequences, such as high blood pressure, stroke, or heart attack, because ephedra influences the nervous system and the way the heartbeat is regulated (Mayo Clinic Proceedings, 2002, vol. 77, no. 1; New England Journal of Medicine, 2000, vol. 343, no. 25).
However, research shows that ephedra is safe when used in recommended doses. Douglas S. Kalman, MS, RD, FACN, a researcher at the clinical research organization Miami Research Associates who has published numerous studies on ephedra-based products' effects on weight loss, has found that small doses of ephedra taken once daily (20 mg ephedra combined with 200 mg caffeine) are effective for weight loss and have no apparent negative effects. "However," Kalman cautions, "we were very careful about the patients we allowed in our clinical trial. For example, before the study even began, we excluded anyone with heart disease or unstable hypertension. People who are not in optimal cardiovascular health should be very careful about using ephedra." Also, the doses of ephedra used in Kalman's trial involved one-third the amount of the herb used in most ephedra-based diet aids.
Harvey, chief science officer of the NNFA, finds Congress' consideration of an outright ban on ephedra too drastic. "Politicians and the media are relentless in trying to find the negative [in ephedra], but we should keep in mind that ephedra has been used in Traditional Chinese Medicine for 5,000 years."
More problematic some experts believe, is the herb's misuse by drug users, who aren't necessarily looking at the weight loss benefits. "What we and most other associations are really pushing for with Congress and the FDA is to actively work against the use of ephedrine [a substance derived from the plant ephedra] as a so-called street-drug alternative," says Kim Smith, the NNFA's director of legislative affairs. "This is when the potential for abuse comes in because people are taking large quantities in order to get a high that is similar to that of street drugs."
The secret to using ephedra safely as a weight loss drug is to stick to the proper doses. "Ephedra is effective in weight loss," says Harvey, "and our organization, along with others, such as the America Herbal Products Association, have put out pamphlets and educational statements urging people to stick to the recommended doses. Most ephedra products have significantly detailed warning labels, and anyone who is considering taking this supplement should take those labels seriously and see their doctor or health care professional if they have any questions."
No matter what, if you're thinking of taking ephedra as a weight loss drug, first speak with your doctor. Note that the U.S. Department of Health and Human Services (HHS) issued a report in June 2002 that cautioned pregnant or nursing women to avoid all ephedra products. HHS also suggests that only adults over the age of 18 use these products and that anyone with a history of high blood pressure, heart or thyroid disease, depression, diabetes, or prostate enlargement or using any prescription medication should consult a health professional before using ephedra. HHS also recommends that ephedra use be discontinued if any of the following symptoms develop: rapid or irregular heartbeat, chest pain, severe headache, shortness of breath, dizziness, loss of consciousness, sleeplessness, or nausea.
Finally, some companies market "natural" weight loss products that actually contain synthetic ephedrine—that is, ephedrine not derived from a plant—and these should be avoided, according to HHS. Although this mislabeling is illegal and HHS is actively pursuing manufacturers that use such marketing practices, it is still a good idea to read the label of an ephedra product and make sure that the ingredients come from either "whole plant" or "botanical" extracts.
St. John's wort (Hypericum perforatum)
The claim: St. John's wort has no effect on depression.
The truth: St. John's wort is beneficial in treating mild to moderate depression, but has been shown to be ineffective in treating severe depression.
The controversy surrounding St. John's wort, commonly used nowadays as a natural treatment for mild to moderate depression, involves several research studies that many in the media have presented as proof that the herb doesn't improve symptoms of depression. In 2001, an article in the Journal of the American Medical Association (JAMA) reported the results from studies done at 11 academic medical centers in the United States showing St. John's wort was ineffective against major depression (2001, vol. 285, no. 15). But many in the media misinterpreted the details of this study. For one, herbalists and alternative health care practitioners recommend St. John's wort as a treatment for mild or moderate depression, not major depression; however, many articles didn't explain this distinction. Some 30 studies have in fact shown St. John's wort to be effective in treating less severe depression. Research suggests that the herb is at least as effective in treating mild to moderate depression as prescription medications are (Clinical Therapeutics, 2000, vol. 22, no. 4).
The study reported in JAMA also found the pharmaceutical sertraline (Zoloft) to be only slightly more effective than a placebo in easing the depression of patients in the study. Yet this wasn't nearly as widely reported as St. John's wort's supposed ineffectiveness. (It should be noted that the multicenter study was supported in part by a grant from Pfizer, manufacturer of both Zoloft and St. John's wort extract.)
In another study, St. John's wort stood up well in a head-to-head comparison with sertraline. Researchers in Montreal compared the effects of this prescription medication to St. John's wort in patients suffering from major depression and found that sertraline was not significantly better at treating major depression than the herb. In fact, the researchers concluded that St. John's wort is a better first-step treatment choice because it produced fewer side effects than did the sertraline (Canadian Family Physician, 2002, vol. 48).
Although St. John's wort appears to be an effective treatment for mild to moderate depression, it's still important to observe some precautions. "As far as I know, there's not much toxicity associated with this drug, but people need to be aware that St. John's wort is just that—a drug," says Joel E. Gallant, MD, MPH, of Johns Hopkins University School of Medicine, who has written on the interactions of St. John's wort with other drugs. "It can interact with other kinds of medications, so if someone is thinking about incorporating it into their diet, they really need to make sure that it won't react badly with something else that they are taking." For example, some studies have shown that St. John's wort can hinder HIV medications and chemotherapy, so people undergoing those treatments should seek a doctor's advice before using this supplement (Phytomedicine, 2001, vol. 8, no. 2; Biochemical Pharmacology, 2001, vol. 62, no. 8).
Overall, if you're looking to ease symptoms of mild to moderate depression—meaning you have low moods from time to time—St. John's wort appears to be effective and safe. More severe depression warrants medical treatment from a health care practitioner. It's also important to note that St. John's wort can decrease blood levels of certain prescription drugs, including blood thinners, oral contraceptives, and antivirals. So, as always, be sure to consult with your health care practitioner and follow the recommended doses when you use this herbal supplement.
Gargi Talukder, PhD, a science writer and first-year law student at the University of Chicago, has become a fan of tofu since starting her research for this article. She has now gained a reputation among her friends as a "tofu junky."