This weekend I noticed horsetail Equisetum arvensis poking up, making its first appearance of the year. It’s a natural source of silica and very good for strengthening hair, bone and brittle nails, and also high in antioxidants, helping to prevent abnormal cell growth (Cetojević-Simin et al, 2010). Silica helps to bind protein molecules together in the blood vessels and connective tissues, and is the material of which collagen is made. Collagen being the connective “glue” that holds our skin and muscle tissues together. Horsetail is a biosilicifier (Law and Exley, 2011) and also contains potassium, manganese, and magnesium, and many trace minerals.
You can make it into a tea by pouring boiling water over the fresh or dried herb to infuse. However, if you want the full benefit of the silica (around 5%) you should juice it as less than half a percent is water soluble. The juice has a pleasant taste but only juice it when freshly picked. This is for a simple mechanical reason – if you let it start to dry out, it will burn out even the most powerful juicer. Believe me, I’ve done it when I left a bag of horsetail overnight instead of juicing it as soon as I’d picked it!!
Medicinally, it helps with osteoporosis. As it contains silicon, a mineral needed for bone health, it has been used to treat osteoporosis. A clinical trial of 122 Italian women showed that taking horsetail improves bone density and is worthy of further study in this area. It is also a diuretic and often used in combination with other herbs to treat kidney stones. Clinical trials have also shown it to have an antidiabetic effect (Safiyeh et al, 2007) without any side effects of liver problems (Baracho et al, 2009). Modern uses also include it as an ingredient in treatments for prostate problems as its diuretic properties are useful in reducing nocturia – the need to get up and pee in the night!
A 1:10 dilution of horsetail essential oil has also been found to be highly effective against bacteria including; Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteritidis; fungi: Aspergillus niger and Candida albicans (Radulović, Stojanović & Palić, 2006). Again it just shows that plants do not like bacteria any more than we do!
The Ancient Greeks and Romans also used it to staunch bleeding, heal ulcers and wounds, and treat tuberculosis and kidney problems.
The botanical name Equisetum come from ‘equus’ – horse and ‘seta’ – brittle. The strength of the silica in it makes the plant an excellent substitute for a Brillo pad, to scrub up your pots and pans when living wild. Its stem is jointed and easy to pop apart. Children can be kept entertained for hours with its natural “Lego-type” ability to be taken apart and then put back together – in a different order!
It is one of the most primitive of plant forms belonging to a species over 100 million years old, and it reproduces by spores not seeds. It is a “living fossil” like the Gingko biloba and the Monkey Puzzles Araucaria araucana trees here. It is also related to the fern.
Historically, during the Gold Rush in the USA, miners would look for horsetail growing in sandy soil on river banks they were prospecting. Horsetail will greedily absorb molecular gold in solution, possibly more than any other plant, but still less than 1 part per million – not a sufficient quantity to warrant extraction! More recently in Canada, engineers using geobotany, will burn horsetail and analyse the mineral content of the ashes.
Horsetail is particularly fond of damp areas around streams, bogs, ditches and the margins of ponds. Here at Wychmoss, it grows quite happily alongside blue flag and skunk cabbage in the damp area where the mill streams dives underground.
Herbal tea: 2 – 3 teaspoonfuls in hot water, 3 times a day. Pour hot water onto the horsetail and let it infuse for 5 – 10 minutes.
Tincture (1:3 or 1:5): From 1 – 5ml, 3 times a day
Standardized dose: 300 mg, 3 times a day, standardized to contain 10 – 15% silica
External (e.g. compresses): 10 g of herb per 1 litre water daily. It can also be used as a facial wash.
Very large doses of horsetail Equisetum arvense taken over a period of time could lead to vitamin B1 (thiamin) deficiency as it also contains an enzyme called thiaminase, which depletes thiamin (Fabre, Geay & Beaufils, 1993). It should not be taken during pregnancy as it contains selenium or during treatment for conditions where maintenance of vitamin B1 is essential. Horsetail also contains small amounts of nicotine and should not be used with nicotine patches if you are trying to give up smoking.
Baracho NC, Vicente BB, Arruda GD, Sanches BC, Brito J. (2009) Study of acute hepatotoxicity of Equisetum arvense L. in rats. Acta Cir Bras. 24(6):449-53. PMID: 20011829
Cetojević-Simin DD, Canadanović-Brunet JM, Bogdanović GM, Djilas SM, Cetković GS, Tumbas VT, Stojiljković BT. (2010) Antioxidative and antiproliferative activities of different horsetail (Equisetum arvense L.) extracts. J Med Food.13(2):452-9. PMID: 20170379
Chaadaeva AV, Tenkeeva II, Moiseeva EV, Svirshchevskaia EV and Demushkin VP. (2009)Antitumor activity of the plant remedy peptide extract PE-PM in a new mouse T-lymphoma/eukemia model. Biomed Khim. 55(1):81-8.PMID: 19351037
Fabre B, Geay B and Beaufils P. (1993) Thiaminase activity in Equisetum arvense and its extracts. Planta Med Phytother. 26:190–197.
Graefe EU and Veit M. (1999) Urinary metabolites of flavonoids and hydroxycinnamic acids in humans after application of a crude extract from Equisetum arvense. Phytomedicine. 6(4):239-46. PMID: 10589442
Law C and Exley C. (2011) New insight into silica deposition in horsetail (Equisetum arvense). BMC Plant Biol.11: 112. PMID: 21801378
Oh H, Kim DH, Cho JH and Kim YC. (2004) Hepatoprotective and free radical scavenging activities of phenolic petrosins and flavonoids isolated from Equisetum arvense. Journal of Ethnopharmacology. 95(2-3):421-4. PMID: 15507369
Radulović N, Stojanović G, Palić R. (2006) Composition and antimicrobial activity of Equisetum arvense L. essential oil. Phytotherapy Research. 20(1):85-8. PMID: 16397851
Safiyeh S, Fathallah FB, Vahid N, Hossine N and Habib SS. (2007) Antidiabetic effect of Equisetum arvense L. (Equisetaceae) in streptozotocin-induced diabetes in male rats. Pak J Biol Sci. 10(10):1661-6. PMID: 19086514
Soleimani S, Azarbaizani FF, Nejati V. (2007) The effect of Equisetum arvense L. (Equisetaceae) in histological changes of pancreatic beta-cells in streptozotocin-induced diabetic in rats. Pak J Biol Sci. 10(23):4236-40. PMID: 19086577
Stajner D, Popović BM, Canadanović-Brunet J and Boza P. (2006) Free radical scavenging activity of three Equisetum species from Fruska gora mountain. Fitoterapia. 77(7-8):601-4. PMID: 16934417
Copies of clinical trials can be found at http://www.ncbi.nlm.nih.gov/pubmed/ by searching on the PMID number after each reference.