Eastern hemlock (Tsuga canadensis)
Natural Standard Bottom Line Monograph, Copyright © 2013 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.
While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.
Alpha-Phellandrene, alpha-pinene, beta-phellandrene, beta-pinene, bornyl acetate, camphene, Canada pitch, Canadian hemlock, catechin, epicatechin, flavan-3-ols, flavanols, hemlock bark, hemlock gum, hemlock spruce, Hemlocktanne, limonene, myrcene, Pinaceae (family), Pinus bark, Pinus extract, proanthocyanidins, Pruche de l'est, tannin, terpinolene, tricyclene, Tsuga canadensis Carriere, Tsuga Canadensis, L.
Eastern hemlock contains tannins (organic compounds), which are responsible for some of its medicinal properties. The bark has astringent properties, and the leaves contain significant amounts of vitamin C.
Traditionally, Eastern hemlock was used to treat digestive disorders, mouth/throat disorders, and diarrhea.
Although the Eastern hemlock is primarily used for lumber today, Native Americans used the tree's cambium (the tissue in a plant that produces new cells) in breads, soups and pemmican (dried, pounded meat mixed with fat and berries). Early settlers also used the tree in dying wool and tanning leather.
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.
No available studies qualify for inclusion in the evidence table.
*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 against this use (it may not work); F: Strong scientific evidence against this use (it likely does not work).
The below uses are based on tradition or scientific theories. 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 health care professional.
Anti-inflammatory, aromatherapy, astringent, diaphoretic (promotes sweating), diarrhea, digestive disorders, diuretic, gastrointestinal distress, liniment (medicinal liquid for massage), mouth and throat inflammation, rheumatic pain, scurvy (vitamin C deficiency).
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (over 18 years old)
There is no proven safe or effective dose for Eastern hemlock in adults, and use is not recommended.
Children (under 18 years old)
There is no proven safe or effective dose for Eastern hemlock in children, and use is not recommended.
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 Eastern hemlock.
Side Effects and Warnings
Little information is available on the adverse effects of Eastern hemlock. However, due to its high tannin content, Eastern hemlock may cause gastrointestinal upset, necrosis (tissue death) of the liver or kidney damage. Eastern hemlock is possibly unsafe when used in patients with impaired liver or kidney function.
Pregnancy and Breastfeeding
Eastern hemlock is not recommended in pregnant or breastfeeding women due to a lack of available scientific evidence.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. 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.
Interactions with Drugs
Theoretically, concomitant ingestion may cause precipitation of some drugs due to the high tannin content of Eastern hemlock. Consult with a qualified healthcare professional, including a pharmacist, to check for any interactions.
Interactions with Herbs and Dietary Supplements
Theoretically, concomitant ingestion may cause precipitation of some herbs due to the high tannin content of Eastern hemlock. Consult with a qualified healthcare professional, including a pharmacist, to check for any interactions.
This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.
Broeckling CD, Salom SM. Volatile emissions of eastern hemlock, Tsuga canadensis, and the influence of hemlock woolly adelgid. Phytochemistry 2003;62(2):175-180. View Abstract
Feucht W, Treutter D, Polster J. Flavanol binding of nuclei from tree species. Plant Cell Rep. 2004;22(6):430-436. View Abstract
Forest Service. Eastern Hemlock. American Woods--FS-239 1970. View Report
Mitchell, J. C. Patch test results - screening set and plants. Contact Dermatitis Newsletter 1970;8:177.
Copyright © 2013 Natural Standard (www.naturalstandard.com)
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.
March 22, 2017