Should you visit an herbal practitioner?

Summarized by Robert W. Griffith, MD
October 2, 2000 (Reviewed: December 18, 2002)

Herbs have been used as medicines for centuries, but recently there has been a considerable upswing in their use. This is partly because they are readily available without prescription, they are comparatively cheap, and they are widely advertised with promises of effectiveness. A recent review of the practice of herbal medicine has been published by the British Medical Journal as part of a series they are running on complementary medicine.

Herbal practitioners only rarely have conventional medical qualifications. Some have had comprehensive training in herbal medicine for up to two years, while others have merely completed a two-day introductory course leading to a diploma. Some countries have set up certification programs in an attempt to provide a registry of qualified herbal practitioners, but this is not common.

The practice of herbal medicine differs from that of conventional medicine. First, the whole plant is used in herbal preparations, usually as an unpurified extract with several different active constituents. (In contrast, an approved conventional medication contains a single, highly-purified, active substance together with a number of pure inactive ingredients; it has similar contents from batch to batch, and is manufactured under tight quality controls.) Herbalists claim that having several active ingredients allows them to work together (i.e. in synergy), while toxicity is reduced because of buffering effects of one constituent on another. Often several different herbs are mixed together, a procedure that herbalists claim improves the benefits of synergy and buffering.

An herbal practitioner takes a history and performs a physical exam in the same way as a medical practitioner. However, the emphasis is on every-day functions, such as appetite, digestion, elimination, and sleep. The herbalist prescribes medications to correct an apparent upset in a bodily function, rather that to counteract a pathological process. An herbal practitioner will speak of "the underfunctioning of the systems of elimination" in someone with arthritis, and prescribe a diuretic (to increase urination) or a laxative combination of herbs. Every prescription is individualized, and is usually accompanied by advice on necessary diet and lifestyle changes.

Plant extracts contain pharmacologically active substances, and many can be shown to be effective in different disease conditions: St. John's wort, ginger, feverfew, and gingko are among them. However, in their review the authors point out that there is little evidence that herbal medicine as practiced is actually effective. One well-conducted study has shown that a traditional Chinese herbal eczema treatment is successful in treating people with eczema that is resistant to other, conventional treatments. This study is a rarity, in so far that such trials are not often reported.

Toxicity can be a problem with herbal medicines, either because of one or other of the ingredient's actions, or, more often, because of contamination, or false labeling of the preparation. Herbal preparations are not generally regulated for safety and content uniformity in the same way as conventional medicines.

Dangerous interactions can sometimes occur in people taking herbs and conventional medicines at the same time. The best-known example is the effect of St. John's wort on the blood levels of several conventional drugs, including some oral contraceptives, blood pressure medicines, the graft-rejection suppressing agent cyclosporine, and some antibiotics and antifungals. In the article there is a list of 22 herbs that may have such interaction properties. It's therefore important that people taking herbs tell their doctor or pharmacist about this when a medicine is prescribe for them, and those taking conventional medicines don't start taking an herb without checking with their health professional.

The article gives a good overview of the role of herbal medicine within the context of overall medical treatment. The authors have recently published their "ABC of Complementary Medicine", which covers, in addition to herbal medicine, other aspects of non-conventional medical treatment, such as acupuncture, nutritional supplements, and massage therapy.

Source

• ABC of complementary medicine: Herbal Medicine. A. Vickers, C. Zollman, Brit Med J, 2000, vol. , pp. --

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