Thursday, September 9, 2010
What is herbal medicine?
Herbal medicine, also called botanical medicine or phytomedicine, refers to the use of any plant's seeds, berries, roots, leaves, bark, or flowers for medicinal purposes. Long practiced outside of conventional medicine, herbalism is becoming more mainstream as up-to-date analysis and research show their value in the treatment and prevention of disease.
What is the history of herbal medicine?
Plants had been used for medicinal purposes long before recorded history. For example, ancient Chinese and Egyptian papyrus writings describe medicinal plant uses. Indigenous cultures (e.g., African and Native American) used herbs in their healing rituals, while others developed traditional medical systems (e.g., Ayurveda and Traditional Chinese Medicine) in which herbal therapies were used systematically. Scientists found that people in different parts of the globe tended to use the same or similar plants for the same purposes.
Recently, the World Health Organization estimated that 80% of people worldwide rely on herbal medicines for some aspect of their primary healthcare.
How do herbs work?
For most herbs, the specific ingredient that causes a therapeutic effect is not known. Whole herbs contain many ingredients, and it is likely that they work together to produce the desired medicinal effect. Many factors affect how effective an herb will be. For example, the type of environment (climate, bugs, soil quality) in which a plant grew will affect its components, as will how and when it was harvested and processed.
How are herbs used?
Herbalists prefer using whole plants rather than extracting single components from them. Whole plant extracts have many components. These components work together to produce therapeutic effects and also to lessen the chances of side effects from any one component. Several herbs are often used together to enhance effectiveness and synergistic actions and to reduce toxicity. Herbalists must take many things into account when prescribing herbs. For example, the species and variety of the plant, the plant's habitat, how it was stored and processed, and whether or not there are contaminants.
What happens during a visit to an herbalist?
Herbalists aim to correct imbalances, resolve patterns of dysfunction, and treat the underlying cause of your complaint. Specific symptoms may also be treated if necessary.
A session with an herbalist typically lasts one hour. You may be physically examined and asked about your medical history and your general well-being (that is, how well you sleep, what you eat, if you have a good appetite, good digestion and elimination, how often you exercise, and what you do to relax). The herbalist might recommend one or more herbs, dietary changes, and lifestyle modifications.
What is herbal medicine good for?
Herbalists treat many conditions such as asthma, eczema, premenstrual syndrome, rheumatoid arthritis, migraine, menopausal symptoms, chronic fatigue, and irritable bowel syndrome, among others. Herbal preparations are best taken under the guidance of a trained professional. Be sure to consult with your doctor or an herbalist before self-treating. Some common herbs and their uses are discussed below. Please see monographs on individual herbs for detailed descriptions of uses as well as risks, side effects, and potential interactions.
* Ginkgo ( Ginkgo biloba ), particularly a standardized extract known as EGb 761, appears to produce improvements in awareness, judgment, and social function in people with Alzheimer's disease and dementia. In a year-long study of 309 people with Alzheimer's disease, those taking EGb 761 consistently improved while those on placebo worsened.
* Kava kava ( Piper methysticum ) has become popular as a treatment for anxiety, but recent reports have traced liver damage to enough people who have used kava that the U.S. FDA has issued a warning regarding its use and other countries, such as Germany and Canada, have taken kava off of the market.
* St. John's wort ( Hypericum perforatum ) is well known for its antidepressant effects, and an analysis of 27 studies involving more than 2,000 people confirmed that the herb is an effective treatment for mild to moderate depression.
* Valerian ( Valeriana officinalis ) has had a long tradition as a sleep-inducing agent, with the added benefit of producing no hangover feeling the next day.
* Echinacea preparations (from Echinacea purpurea and other Echinacea species) may bolster immunity. In a study of 160 volunteers with flu-like symptoms, echinacea extract reduced both the frequency and severity of cold symptoms.
Is there anything I should watch out for?
Used correctly, many herbs are considered safer than conventional medications, but because they are unregulated, herbal products are often mislabeled and may contain undeclared additives and adulterants. Some herbs are associated with allergic reactions or interact with conventional drugs. Self-prescribing herbal products will increase your risk, so it is important to consult your doctor and an herbalist before taking herbal medicines.
Some examples of adverse reactions from certain popular herbs are described below.
* St. John's wort causes sensitivity to the sun's ultraviolet rays, and may cause an allergic reaction, stomach upset, fatigue, and restlessness. Studies show that St. John's wort also interferes with the effectiveness of many drugs, including warfarin (a blood thinner), protease inhibitors for HIV, possibly birth control pills, and many other medications. In addition, St. John's wort must not be taken with anti-depressant medication. The Food and Drug Administration (FDA) has issued a public health advisory concerning many of these interactions.
* Kava kava and echinacea have both been linked to liver toxicity. Again, kava has been taken off the market in several countries because of the liver toxicity.
* Valerian may cause oversedation, and in some people it may even have the unexpected effect of overstimulating instead of sedating.
* Feverfew ( Tanacetum parthenium ) may cause agitation.
* Bleeding time may be altered with the use of garlic, ginkgo, feverfew, ginger ( Zingiber officinale ) and ginseng.
Who is using herbal medicine?
Nearly one-third of Americans use herbs and it is estimated that in 1998 alone $4 billion was spent on herbal products in this country. Unfortunately, a recent study in the New England Journal of Medicine indicated that nearly 70% of individuals taking herbal medicines (the majority of which were well educated and had a higher-than-average income) were reluctant to reveal their use of complementary and alternative medicine to their doctors. Because herbal medicines contain a combination of chemicals, each with a specific action, many are capable of eliciting complex physiological responses—some of which may create unwanted or unexpected results when combined with conventional drugs. Be sure to consult your doctor before trying any herbal products.
What is the future of herbal medicine?
Although a renaissance is occurring in herbal medicine in the United States, the FDA still classifies herbs as dietary supplements and forbids manufacturers to claim that their products are able to treat or prevent specific diseases. In some countries in Europe, however, herbs are classified as drugs and are regulated. The German Commission E, an expert medical panel, actively researches their safety and effectiveness.