Nettles

Common name: Nettles
Other names: Stinging nettles
Latin name: Urtica dioica
Affinity: Immune system, circulatory system
Actions: Tonic, diuretic, astringent
Diseases: Arthritis(3), allergies(2), diabetes(2), BPH(1), asthma(3), bronchitis(3)
Parts used: Leaf or root

nettles

Characteristics: Stinging nettles are a common perennial found throughout Europe, the U.S.A., and most temperate climates (Winston, 2007). They often grow 3 to 4 feet tall. They are often found in wastelands, gardens, and woodlands (Safarinejad et al., 2005). The genus name ‘urtica’ is derived from uro meaning ‘to burn’ or urere ‘to sting’ (Upton, 2013).

History: The medicinal use of nettle goes back to the ancient Greeks as around the 3rd century it was prescribed externally to treat snakebites, while internally as an antidote for certain poisons (Castleman, 2001). The Romans are also said to have used nettle as a treatment for getting too cold when they first invaded Britain in the 1st century (Warren, 2006), as they found the sting warmed their skin and this treatment evolved into urtication for arthritis (Castleman, 2001). Early European herbalists used the tea for a treatment for cough and tuberculosis. 17th century herbalist Nicholas Culpepper endorsed all of nettles treatments prior to him and believed the ‘decoction of the leaves in wine is … good to promote women’s courses’. Native American women thought nettle tea during pregnancy strengthened the unborn child and eased delivery. Later the Eclectics, Americas 19th century physicians, used nettle as a diuretic to treat bladder, urinary, and kidney problems.

Current applications: David Hoffman in his text, ‘Holistic Herbal’, states, ‘Nettles are one of the most widely applicable plants we have. They strengthen and support the whole body’ (Hoffman, 1988). He also mentions they are specific for childhood eczema. Thomas Bartram recommends nettles for, anaemia, gout, to stimulate the kidneys, detoxify the blood, chronic skin disorders, high blood sugar in diabetes, weak digestion, and high blood pressure (Bartram, 2013). He quotes, Hilda Leyel, an English expert in herbal medicine in the early 20th century, writing, ‘No plant is more useful in domestic medicine’.

Science: Nettles have been studied using various experimental models and found to have diverse activities, including anti-oxidant, anti-microbial, anti-ulcer, and analgesic properties (Gülçin et al., 2004). There are a few human studies which have been reasonably large and well controlled. One study examined whether nettle leaf could reduce the symptoms of allergic rhinitis, which is otherwise known as allergies to dust, pollen and so on, they found it could compared with a placebo (Mittman et al., 1990). Two studies examined if nettle leaf extract could reduce inflammation and oxidative stress in type II diabetes, both found a statistical improvement with treatment (Namazi et al., 2011; Namazi et al., 2012). One very large study (n = 620) found a significant reduction in symptoms of BPH with nettle root treatment (Safarinejad et al., 2005). These data support the traditional use of nettles to some extent, but much more work is required.

Safety: Nettles are very safe when dried in capsules or as a tincture. Nettles may safely be used during pregnancy or breastfeeding.

Dosage: 1-4ml of tincture two or three times daily.

Brands: I recommend Vogel for the U.K., and in the U.S. Herb Pharm.

Scientific Summary

Research on models

Anti-oxidant effects: In one study, using various experimental models, the antioxidant properties of water extracted nettle extract was tested using various methods, including reducing power, free radical scavenging, and superoxide anion radical scavenging activities. Nettles was found to have powerful antioxidant activity (Gülçin et al., 2004).

Anti-microbial: In one study, water extracted nettle extract showed antimicrobial activity against nine microorganisms (Gülçin et al., 2004).

Anti-ulcer: In the same study, water extracted nettle extract was found to display antiulcer activity against ethanol-induced ulcer formation in vivo models (Gülçin et al., 2004).

Analgesic: In a study water extracted nettle extract was found to have analgesic activity against acetic acid-induced stretching (Gülçin et al., 2004).

Research on humans

Allergic rhinitis: One study (n=69, double blind placebo controlled) found a general improvement in overall global symptom scores compared with a placebo, but did not conduct statistic analysis (Mittman et al., 1990). Patients took a mean of 3 capsules per day of 300mg dried leaf nettle extract, however, dose varied from 1 to 7 doses per day.

Inflammation in type II diabetes: Another study (n=50, double blind placebo controlled) over 8 weeks found 100mg per kg three times daily reduced the levels of inflammatory markers CRP and IL-6 (Namazi et al., 2011). The extract was an ethanol extracted.

Oxidative stress in type II diabetes: A study (n=50, double blind placebo controlled) over 8 weeks found 100mg per kg three times daily acting as an anti-oxidant (Namazi et al., 2012). Total Antioxidant Capacity and Superoxidant Dismutase significantly increased in the treatment group compared to the control.

BPH: One study (n = 620, double blind placebo controlled) examined the effects of treatment with 100mg of nettle extract three times daily (Safarinejad et al., 2005). There was a significant reduction in BPH symptoms in the treated group.

References:

Bartram, Thomas. Bartram’s encyclopedia of herbal medicine. Hachette UK, 2013.

Castleman, Michael. “The new healing herbs.” Bantam Book, New York (2001): 465-471.

Gülçin, Ilhami, et al. “Antioxidant, antimicrobial, antiulcer and analgesic activities of nettle (Urtica dioica L.).” Journal of ethnopharmacology 90.2 (2004): 205-215.

Hoffman, David. Holistic herbal. Element Books, 1988.

Mittman, Paul. “Randomized, double-blind study of freeze-dried Urtica dioica in the treatment of allergic rhinitis.” Planta Medica 56.01 (1990): 44-47.

Namazi, N., A. Tarighat, and A. Bahrami. “The effect of hydro alcoholic nettle (Urtica dioica) extract on oxidative stress in patients with type 2 diabetes: a randomized double-blind clinical trial.” Pakistan journal of biological sciences: PJBS 15.2 (2012): 98-102.

Namazi, N., et al. “The effect of hydro alcoholic Nettle (Urtica dioica) extracts on insulin sensitivity and some inflammatory indicators in patients with type 2 diabetes: a randomized double-blind control trial.” Pakistan journal of biological sciences: PJBS 14.15 (2011): 775-779.

Nick, Gina L. “Natural therapies for the prostate gland: a scientific review of nutrient and herbal combinations that promote prostate health.” Townsend Letter for Doctors and Patients 257 (2004): 66-76.

Safarinejad, Mohammad Reza. “Urtica dioica for treatment of benign prostatic hyperplasia: a prospective, randomized, double-blind, placebo-controlled, crossover study.” Journal of herbal pharmacotherapy 5.4 (2005): 1-11.

Upton, Roy. “Stinging nettles leaf (Urtica dioica L.): Extraordinary vegetable medicine.” Journal of Herbal Medicine 3.1 (2013): 9-38.

Warren, Piers. 101 uses for stinging nettles. Wildeye, 2006.

Winston, David, and Steven Maimes. Adaptogens: herbs for strength, stamina, and stress relief. Inner Traditions/Bear & Co, 2007.