What is herbal medicine?
Herbal medicine, phytomedicine, or botanical medicine, refers to the use of a plant's seeds, berries, roots, leaves, bark, or flowers for medicinal purposes.
Herbalism is becoming more mainstream as improvements in analysis and quality control along with advances in clinical research show their value in the treatment and prevention of disease.
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 (such as African and Native American) used herbs in their healing rituals, while others developed traditional medical systems (such as 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 health care. In the last 20 years in the United States, increasing public dissatisfaction with the cost of prescription medications, combined with an interest in returning to natural or organic remedies, has led to an increase in the use of herbal medicines. In Germany, roughly 600 - 700 plant-based medicines are available and are prescribed by approximately 70% of German physicians.
Many factors determine 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.
Herbal medicine treats many conditions, such as asthma, eczema, premenstrual syndrome, rheumatoid arthritis, migraine, menopausal symptoms, chronic fatigue, and irritable bowel syndrome, among others. Herbal supplements are best taken under the guidance of a trained health care provider. Be sure to consult with your doctor or pharmacist before self-treating. Some common herbs and their uses are discussed below.
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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. Randomized controlled studies assessing the use of ginkgo supplements for Alzheimer's disease in individuals older than 65 years have produced positive results.
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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. Food and Drug Administration (FDA) issued a warning regarding its use, while other countries, such as Germany, France, and Canada, have taken kava off of the market. However, there is no definitive proof that kava alone is responsible for liver damage in humans. Kava has been used traditionally for thousands of years.
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Saw palmetto (Serenoa repens) is used by over 2 million men in the United States for the treatment of benign prostatic hyperplasia (BPH). The evidence suggests that saw palmetto provides mild-to-moderate improvement in urinary symptoms and flow measures. Saw palmetto produces similar improvement in urinary symptoms and flow compared to finasteride (Proscar), a pharmaceutical drug used in BPH, and is associated with fewer adverse treatment events.
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St. John's wort (Hypericum perforatum) is well known for its antidepressant effects. The clinical efficacy of some standardized St. John's wort standardized extracts in the treatment of mild and moderate depression has been demonstrated in about 40 controlled clinical trials.
• 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.
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Echinacea preparations (from Echinacea purpurea and other Echinacea species) may improve the body's natural immunity. Echinacea is one of the most commonly used herbal products, but controversy exists about its benefit in the prevention and treatment of the common cold. A meta-analysis of 14 clinical studies evaluating the effect of echinacea on the incidence and duration of the common cold found that echinacea supplements decreased the odds of developing the common cold by 58% and the duration of a cold by 1.4 days.
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 or pharmacist before taking herbal medicines. Some examples of adverse reactions from certain popular herbs are described below.
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St. John's wort causes sensitivity to the sun's ultraviolet rays, and may cause an allergic reaction, stomach upset, fatigue, and restlessness. Clinical studies report that St. John's wort also interferes with the effectiveness of many drugs, including warfarin (Couamdin, a blood thinner), protease inhibitors for HIV, birth control pills, certain asthma drugs, and many other medications. In addition, St. John's wort should not be taken with prescribed anti-depressant medication. The FDA has issued a public health advisory concerning many of these interactions.
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Kava kava has been linked to liver toxicity. Kava has been taken off the market in several countries because of the liver toxicity, although the causes remain controversial.
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Valerian may cause oversedation, and in some people it may even have the unexpected effect of overstimulating instead of sedating.
• Bleeding time may be altered with the use of garlic, ginkgo, feverfew, and ginger, among others.
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Evening primrose (Oenothera biennis) may increase the risk of seizures in patients taking drug known to lower seizure threshold, such as anticonvulsants.
• Some herbal supplements, especially those imported from Asian countries, may contain high levels of heavy metals, including lead, mercury, and cadmium. It is important to purchase herbal supplements from reputable manufacturers to ensure quality. Talk to your health care provider for more information.
