There are several kinds of yew including the English or European yew (Taxus baccata), Pacific yew (Taxus brevifolia) and Japanese yew (Taxus cuspidata). All species are considered poisonous; however, there is some debate about the medicinal value of the fruits (arils). The name 'taxus' may be related to the Greek 'toxon' (bow) and 'toxicon' (the poison with which the arrowheads were dressed).
Traditionally, the fruit of yew has been used as an antitussive (preventing or relieving cough), menstrual stimulant, abortifacient (induces abortion), diuretic and laxative. It is reported that the Native Americans used yew extracts to treat rheumatism, fever, and arthritis.
Paclitaxel (Taxol®) was isolated from the bark of the Pacific yew tree (Taxus brevifolia) as early as 1971 and is now approved by the U.S. Food and Drug Administration (FDA). Since 1971, Taxol® has been used as an antitumor drug in clinical trials run by the U.S. National Cancer Institute and has been hailed as one of the most significant advances in cancer chemotherapy in recent history. Since 1990, clinical trials using Taxol® have succeeded in treating advanced ovarian and breast cancers.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
* Key to grades
A: Strong scientific evidence for this use B: Good scientific evidence for this use C: Unclear scientific evidence for this use D: Fair scientific evidence for this use (it may not work) F: Strong scientific evidence against this use (it likley does not work)
Tradition / Theory
The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.
There is no proven safe or effective dose for yew, and use in adults is not recommended.
Children (younger than 18 years)
There is no proven safe or effective dose for yew, and use in children is not recommended. One chewed berry may be lethal.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Avoid in individuals with a known allergy or hypersensitivity to yew. There has been at least one report of anaphylaxis following yew (Taxus) needle ingestion.
Side Effects and Warnings
There is little documentation of adverse effects. However, of those reported, the most common adverse effects include dermal rash, tachycardia (increased heart rate), bradycardia (decreased heart rate), arrhythmia (altered heart rhythm), upset stomach and neurological effects. Death secondary to cardiac arrest has also been reported. There is mixed evidence regarding the prevalence of such effects, and caution is advised. Use berries (fruits, arils) with caution.
Pale and cyanotic skin and other skin effects have been reported. Queasiness, dry mouth, vomiting, severe abdominal pain, dyspepsia, and reddening of the lips have also been associated with yew. Taxus baccata L. may also cause gastric lavage.
Although not well studied, yew may cause hypotension (low blood pressure), nasal allergy, mydriasis (dilation of the pupil), or adverse effects on the liver or kidneys. Vertigo, weakness, nervousness, unconsciousness, trembling, discoordination, artificial respiration, and coma may also occur.
Pregnancy and Breastfeeding
Yew is not recommended in pregnant or breastfeeding women due to a lack of available evidence. Caution is advised as yew has traditionally been used to induce abortion.
Japanese yew, Taxus cuspidata, has been shown to increase the cellular accumulation of vincristine in multidrug-resistant tumor cells. Patients taking anti-cancer drugs should use yew or its derivative product, Taxol®, with caution.
Yew may interact with calcium channel block agents. Caution is advised.
Although not well studied, yew may lower blood pressure. Patients taking blood pressure lowering medications should consult with a qualified healthcare professional, including a pharmacist.
Interactions with Herbs and Dietary Supplements
Japanese yew, Taxus cuspidata, has been shown to increase the cellular accumulation of vincristine in multidrug-resistant tumor cells. Patients taking herbs or supplements for cancer should use yew or its derivative product, Taxol®, with caution.
Although not well studied, yew may lower blood pressure. Patients taking blood pressure lowering herbs and supplements should consult with a qualified healthcare professional, including a pharmacist.
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The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.