Table of Contents > Herbs & Supplements > Black walnut (Juglans nigra) Print

Black walnut (Juglans nigra)

Image

Also listed as: Juglans nigra
Related terms
Background
Evidencetable
Tradition
Dosing
Safety
Interactions
Attribution
Bibliography

Related Terms
  • American walnut, ellagic acid, Juglandaceae (family), Juglans nigra, juglone, methyl 2-benzimidazolylcarbamate, nogal americano noguerira-preta, noyer noir, plumbagin, quinones, sesquiterpenes, Schwarze Walnuss (German), tannins.

Background
  • Black walnut (Juglans nigra) is a large tree known for its high-quality wood and edible nut which is commonly used as a food ingredient.
  • The U.S. Food and Drug Administration (FDA) announced a health claim stating that eating 1.5 ounces per day of walnuts as part of a diet low in fat may reduce the risk of heart disease.
  • Black walnut has been shown to contain chemicals called tannins which may help with irritation and may improve tissue firmness. Traditionally, it has been used to relieve constipation and diarrhea.

Evidence Table

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. GRADE *
* 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.

  • Acne, antibacterial, anti-inflammatory, antioxidant, antiviral, astringent, cancer, colic, constipation, cosmetic uses (hair dye), diarrhea, eczema, headache, heart disease, herpes, high blood pressure, hyperglycemia (high blood sugar levels), indigestion, insect bites, mood enhancement, mouth sores, parasitic worm infections, skin disinfectant/sterilization, sore throat (gargle), syphilis, toothache, warts, wound care.

Dosing

Adults (18 years and older)

  • Black walnut powder has been taken by mouth as a capsule or tablet, and has also been used on the skin.

Children (under 18 years old)

  • There is no proven safe or effective dose for black walnut, and use in children is not recommended.

Safety

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.

Allergies

  • Avoid in patients with known allergy or sensitivity to black walnut, its constituents, including black walnut tree pollen, or to members of the Juglandaceae family. Patients allergic to other nuts may also be allergic to black walnut. Black walnut may irritate the skin.

Side Effects and Warnings

  • Black walnut may irritate the skin and may cause stomach upset. When taken for a long time, black walnut may cause mouth or stomach cancer, or liver or kidney damage. Use cautiously in patients with stomach disorders, or liver or kidney conditions.
  • Black walnut may alter blood pressure or affect blood vessels. Caution is advised in patients taking drugs, herbs, or supplements that alter blood pressure or compress blood vessels.

Pregnancy and Breastfeeding

  • Black walnut is not recommended for pregnant or breastfeeding women due to lack of sufficient data.

Interactions

Interactions with Drugs

  • Black walnut may bind with other drugs when taken at the same time. It is recommended to wait at least two hours before taking any drugs after black walnut.
  • Black walnut may alter blood pressure or affect blood vessels. Caution is advised in patients taking drugs that alter blood pressure or compress blood vessels.
  • Black walnut may have additive effects with laxatives, antimicrobials, drugs used for the stomach, nausea, inflammation, or cancer, or drugs that harm the liver or kidney.

Interactions with Herbs and Dietary Supplements

  • Black walnut may bind with other herbs or supplements when taken at the same time. It is recommended to wait at least two hours before taking any herbs or supplements after black walnut.
  • Black walnut may alter blood pressure or affect blood vessels. Caution is advised in patients taking herbs or supplements that alter blood pressure or compress blood vessels.
  • Black walnut may have additive effects with laxatives, antimicrobials, herbs or supplements used for the stomach, nausea, inflammation, or cancer, herbs or supplements that harm the liver or kidney, or herbs or supplements that contain chemicals called tannins.

Attribution
  • 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).

Bibliography
  1. Amarowicz, R, Dykes, GA, and Pegg, RB. Antibacterial activity of tannin constituents from Phaseolus vulgaris, Fagoypyrum esculentum, Corylus avellana and Juglans nigra. Fitoterapia 2008;79(3):217-219.
  2. Choi, HR, Choi, JS, Han, YN, et al. Peroxynitrite scavenging activity of herb extracts. Phytother Res. 2002;16(4):364-367.
  3. Belknap, JK, Giguere, S, Pettigrew, A, et al. Lamellar pro-inflammatory cytokine expression patterns in laminitis at the developmental stage and at the onset of lameness: innate vs. adaptive immune response. Equine Vet J 2007;39(1):42-47.
  4. Eaton, SA, Allen, D, Eades, SC, et al. Digital Starling forces and hemodynamics during early laminitis induced by an aqueous extract of black walnut (Juglans nigra) in horses. Am J Vet Res. 1995;56(10):1338-1344.
  5. Fontaine, GL, Belknap, JK, Allen, D, et al. Expression of interleukin-1beta in the digital laminae of horses in the prodromal stage of experimentally induced laminitis. Am J Vet Res. 2001;62(5):714-720.
  6. Galey, FD, Beasley, VR, Schaeffer, D, et al. Effect of an aqueous extract of black walnut (Juglans nigra) on isolated equine digital vessels. Am J Vet Res. 1990;51(1):83-88.
  7. Hurley, DJ, Parks, RJ, Reber, AJ, et al. Dynamic changes in circulating leukocytes during the induction of equine laminitis with black walnut extract. Vet Immunol Immunopathol. 4-15-2006;110(3-4):195-206.
  8. Inbaraj, JJ and Chignell, CF. Cytotoxic action of juglone and plumbagin: a mechanistic study using HaCaT keratinocytes. Chem Res Toxicol. 2004;17(1):55-62.
  9. Loftus, JP, Belknap, JK, and Black, SJ. Matrix metalloproteinase-9 in laminae of black walnut extract treated horses correlates with neutrophil abundance. Vet Immunol Immunopathol. 10-15-2006;113(3-4):267-276.
  10. McConnico, RS, Stokes, AM, Eades, SC, et al. Investigation of the effect of black walnut extract on in vitro ion transport and structure of equine colonic mucosa. Am J Vet Res. 2005;66(3):443-449.
  11. Moodley, R, Kindness, A, and Jonnalagadda, SB. Elemental composition and chemical characteristics of five edible nuts (almond, Brazil, pecan, macadamia and walnut) consumed in Southern Africa. J Environ Sci Health B 2007;42(5):585-591.
  12. Qasem, JR. Weed Allelopathy, Its Ecological Impacts and Future Prospects: A Review. Journal of Crop Production. 2001;4(2):43-119.
  13. Riggs, LM, Franck, T, Moore, JN, et al. Neutrophil myeloperoxidase measurements in plasma, laminar tissue, and skin of horses given black walnut extract. Am J Vet Res. 2007;68(1):81-86.
  14. Roux, KH, Teuber, SS, and Sathe, SK. Tree nut allergens. Int Arch.Allergy Immunol. 2003;131(4):234-244.
  15. von Kiparski, G. R., Lee, L. S., and Gillespie, A. R. Occurrence and fate of the phytotoxin juglone in alley soils under black walnut trees. J Environ Qual. 2007;36(3):709-717.

Copyright © 2011 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.

Search Site