Use of herbals and botanicals as alternative medicines is not just for "healers" anymore. According to a NBC News/Prevention magazine poll, approximately 60 million adults use herbal products. Increased interest among consumers may be what is spurring "traditional" medicine practitioners and scientific researchers to take a closer look at herbals' booming trend.
Clearly, herbals' popularity is increasing. However, a designation of "natural" on the label does not necessarily equal efficacy, purity and safety. Because herbal products are not standardized, the same herb can be in different products in varying amounts, which leads to a confusing sea of options. Bernadette Marriott, Ph.D., National Institutes of Health (NIH) Office of Dietary Supplements, noted that all the active ingredients in herbals are not known, and "both basic and clinical research is needed."
Food Insight takes a look at what science says about some of the more popular herbal remedies and issues surrounding botanical use.
St. John's Wort (Hypericum perforatum)
St. John's Wort has been used for over a thousand years in the treatment of several maladies including kidney and lung disorders, and has been used widely in Germany for the treatment of anxiety, depression and sleep disorders.
As with many botanicals, much of the research has been conducted in Europe, and 28 studies were conducted abroad on St. John's Wort. Because of its promise in treating depression, the NIH's National Institute of Mental Health (NIMH), Office of Alternative Medicine, and Office of Dietary Supplements are sponsoring a multi-center, randomized clinical trial of St. John's Wort. The study is comparing St. John's Wort to a placebo and a commonly prescribed antidepressant for patients with major depression. "This study will give us definitive answers about whether St. John's Wort works for clinical depression," said NIMH Director Steven E. Hyman, M.D. "The study will be the first rigorous clinical trial of the herb that will be large enough and long enough to fully assess whether it produces a therapeutic effect."
Ginkgo biloba
Ginkgo biloba comes from the Chinese maidenhair tree that is over 200 million years old, and the plant is one of the most widely studied and prescribed herbal remedies in Europe. One of the first studies of Ginkgo biloba in the United States documented its effectiveness in treating Alzheimer's disease. It has also been found to have positive effects on some types of deafness and macular degeneration and diabetic retinopathy (damage to the eye). It may also have an antidepressant effect. In Germany and France, seven out of eight well-controlled clinical trials showed positive effects of Ginkgo biloba in the treatment of cerebral (brain) dysfunction. Some symptoms typical of cerebral dysfunction include difficulties of concentration, difficulties of memory, absent-mindedness and confusion.
A 52-week, multi-center study of 309 males and females diagnosed with uncomplicated dementia (memory loss) was conducted to determine the efficacy of Ginkgo biloba for dementia. The placebo-controlled, double-blind, randomized trial, published in 1997 in The Journal of the American Medical Association, (278:1327, 1997) concluded: "[Ginkgo] was safe and appears capable of stabilizing and, in a substantial number of cases, improving the cognitive performance and the social functioning of demented patients for six months to one year." Despite these positive results, there were some criticisms of the trial which warrant further research-the study experienced a high dropout rate and one-third of the patients actually got worse.
Echinacea
"The purple coneflower" is thought to stimulate the immune system and enhance the effectiveness of white blood cells in fighting viruses and bacteria. According to speakers at a September 1998 NIH National Institute of Environmental Health Sciences conference on medicinal herbs, it ranks fourth among botanicals sold in the United States. Echinacea has been researched extensively in Europe, but very little research has been conducted on it in the United States. Clinical trials have shown its effectiveness on frequency and severity of respiratory tract infections, but the studies on this herbal are not definitive. Recent data presented at the Fourth Annual Symposium of Complementary Health Care in Exeter, United Kingdom, showed echinacea is not efficacious against upper respiratory infections. In the study of 302 people, there was no significant difference in the outcomes among those who received E. angustifolia, E. purpurea (both echinacea extracts) or placebo. Some studies suggest that enchinacea should not be used for longer than two weeks, and it should be avoided by anyone with an autoimmune disorder, such as lupus or multiple sclerosis. Other studies have shown that some people may be allergic to the herb.
Ginseng (Panax ginseng)
It has been purported that ginseng, among other effects, enhances physical capacity, alertness and concentration, and combats feelings of lethargy. Although animal studies have shown that ginseng at high dosage levels can have ergogenic and other metabolic effects, currently there is not enough data to definitively show similar results in humans. Hermann-J. Engels, Ph.D., F.A.C.S.M., Associate Professor of Exercise Physiology, Wayne State University, conducted two small clinical studies in the United States on healthy adult women (Nutrition Research, 16:1295, 1996) and a follow up study on healthy men (Journal of the American Dietetic Association, 97:1110, 1997) to test ginseng's effect on aerobic work capacity. Dr. Engels stated, "There is presently no strong research support available demonstrating ergogenic potential of ginseng in humans." It is evident that more studies are necessary to determine what effects, if any, ginseng has on human's physiologic and psychological capacities.
Where is the herbal trend heading?
Some believe that as consumers continue to hear more about herbals, their interest will continue to increase. "Herbals can be appealing because some consumers are in the mindset that they are 'not really taking a drug,'" noted Clare Hasler, Ph.D., Functional Foods for Health Program, University of Illinois. The consumer may also be at risk with some products. According to Marcia Angell, M.D., Editor, The New England Journal of Medicine, "Consumers mistakenly assume that dietary supplements are safer than drugs," even though they are warned by the producers that the products are as or more powerful than conventional medicine, and she called for rigorous testing of all products. Herbals themselves are not a "magic bullet" to medicating illness. As with any medication, consumers should always seek the advice of a physician and inform their health care provider of any herbal product usage. Nevertheless, consumer interest combined with further scientific inquiry will likely continue to drive the herbal market.
Information on Herbals
Following are some resources for information on herbals:
- Natural Products Alert (NAPRALERTTM): The Program for Collaborative Research in the Pharmaceutical Sciences at the University of Illinois at Chicago produces this database. Its 160,000 records contain bibliographic and factual data on natural products.
- The United States Pharmacopeia (USP): The USP promotes the public health by establishing and disseminating officially recognized standards of quality and authoritative information for the use of medicines and other health care technologies.
- NIH Office of Alternative Medicine: altmed.od.nih.gov/oam. The NIH Office of Alternative Medicine (OAM) facilitates research and evaluation of unconventional medical practices and disseminates this information to the public.
Using Herbals
In the United States, herbal products are regulated under the Dietary Supplement Health and Education Act (DSHEA) by the Food and Drug Administration (FDA). In 1994, DSHEA removed dietary supplements from the FDA's food additive category, so the burden of proof falls on the FDA to prove lack of safety rather than falling on the supplement manufacturer to prove safety. "There are currently no federal regulations that establish specific criteria for purity, identification and manufacturing procedures of dietary supplements," said Lori Love, Ph.D., Director of Clinical Research and Review Staff, Office of Special Nutritionals, FDA. At the recent conference on medicinal herbs sponsored by the National Institutes of Health's National Institute of Environmental Health Sciences, standardization of herbal products to remove some of the elements of "buyer beware" for consumers who use herbal products was a key issue. Explained Clare Hasler, Ph.D., University of Illinois, "Analytical tests are necessary to determine if you are getting what the package says you are." To address these concerns, the U.S. Pharmacopeia is in the process of developing scientific monographs on herbal products.
Further, recommended Good Manufacturing Practices (GMPs) for dietary supplements have been submitted for review and comment.
Not all herbal remedies are health promoting, and may even be dangerous. The FDA lists the following as "risky supplements:" ephedra; chaparral; comfrey; DHEA; dieter's teas with senna, aloe, rhubarb root, buckthorn, cascara and castor oil; pennyroyal and sassafrass.
