Herbal Medicine: Expanded Commission E
Flaxseed
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Latin Name: Linum usitatissimum
Pharmacopeial Name: Lini semen
Other Names: flax, linseed
Overview
Flax is an annual herb believed to be a native ofEgypt. It has been cultivated worldwide for so many centuries that its geographical origin is uncertain.The material of commerce in Europe comes from Argentina, Morocco, Turkey, India, and other countries (BHP, 1996; Grieve, 1979; Nadkarni, 1976; Wichtl and Bisset, 1994). Flaxseed used in Chinese medicine is produced mainly in Inner Mongolia, Heilongjiang, Liaoning, and Jilin provinces (Yen, 1992) and that used in Indian medicine is extensively cultivated throughout India, mostly in Bengal, Bihar, and the United provinces (Kapoor, 1990; Karnick, 1994; Nadkarni, 1976). Flaxseed is one of the oldest cultivated plants worldwide (Wichtl and Bisset, 1994). Flaxseed, and cloth woven from flax, has been found in Egyptian tombs. The Bible mentions in Exodus 28 that the Jewish high priests wore garments made from flax (Grieve, 1979). Its present-day therapeutic uses in Asia, Europe, and North America can be traced to ancient Roman medicine and probably back even further to ancient Greek and Egyptian medicines. Pliny the Elder (ca. 23–79 C.E.) cited 30 remedies using flaxseed, including oral ingestion as a mild laxative and topical application as a poultice for local inflammation (Carlson, 1998). It is still official in the Chinese pharmacopeia for constipation and dry itching skin (Tu, 1992).The Ayurvedic Pharmacopoeia specifically approves its external use as a poultice for boils and carbuncles and its internal use as a demulcent or laxative (Karnick, 1994). Flaxseed poultices are used for inflammations, abscesses, and relief of pain in American conventional medicine (Taber, 1962) and as an emollient in modern veterinarymedicine (Budavari, 1996). In Germany, flaxseed is usually taken as a laxative, whole or freshly crushed with water. It is also prepared as a mucilage or gruel for demulcent action. Externally it is applied as a hot moist cataplasm, compress, or poultice to reduce inflammation (ESCOP, 1997; Wichtl and Bisset, 1994).In the United States,it is used in the same way, though American consumers are more likely to take flaxseed as a component of a health food or nutraceutical product (e.g., baked goods, breads, bars, breakfast cereals, granolas). The approved modern therapeutic applications for flaxseed are supportable based on its multi-thousand year history of clinical use in well established systems of traditional medicine, in vitro and in vivo studies in animals, nutrient composition and dietary value studies,and numerous human studies. Recent clinical studies suggest significant potential beyond the current, well-documented uses of flaxseed. Flaxseed preparations have had experimental success as anticarcinogens (Serraino and Thompson, 1991,1992a, 1992b) and in treating lupus nephritis (Clark et al., 1995); reducing atherogenic risk in hyperlipemic patients (Bierenbaum et al., 1993) and improving arterial function in obese subjects (Nestel et al., 1997); and positively affecting platelet composition and function (Allman et al., 1995) and nutritional health in humans (Cunnane et al., 1993). Three animal studies showed the dietary addition of flaxseed to reduce cancer incidence in rats. In the first, test animals were given 5 or 10% flax flour supplementation to high-fat diets and researchers found mammary tissue reductions in epithelial cells (39–55%) and nuclear aberrations (59–66%) (Serraino and Thompson, 1991). In the second, test animals were injected with a carcinogen (7,12-dimethylbenz(a) anthracene) before being fed a high-fat diet mixed with 5% flax flour. Tumor size was reduced by 67% (Serraino and Thompson, 1992a). The third study used a single injection of the carcinogen azoxymethane and 5 and 10% flax flour diets and saw a 50% reduction in colon cancer. Preventative effects are apparently due to flaxseed's high levels of lignans. Other studies examined effects of pure lignans (secoisolariciresinol diglucoside) on tumor growth (Serraino and Thompson, 1992b). One small, preliminary study reported that flaxseed supplementation may slow the progression of kidney disease associated with lupus. Nine lupus nephritis patients were enrolled, eight of whom completed the study. After the baseline studies, patients were given 15, 30, and 45 g of flaxseed/day sequentially at four-week intervals, followed by a five-week washout period. Compliance, disease activity, blood pressure, plasma lipids, rheology, PAF-induced platelet aggregation, renal function, and serum immunology were assessed. The 30 g dose performed the best. It significantly reduced total and LDL cholesterol, and blood viscosity. The 30 g/day dose was well tolerated and determined to be beneficial in terms of renal function as well as inflammatory and atherogenic mechanisms important in the pathogenesis of lupus nephritis (Clark et al., 1995). One three-month feeding trial investigated reducing atherogenic risk with flaxseed supplementation. The researchers reported the effects on serum lipids of a flaxseed supplement consisting of three slices of flaxseed-containing bread and 15 g of ground flaxseed in 15 hyperlipemic subjects on long-term intake of vitamin E (800 IU/day). Serum total and LDL cholesterol levels were reduced significantly; HDL cholesterol did not change during flaxseed consumption. Thrombin-stimulated platelet aggregation decreased with the supplement. Serum lipid oxidation products decreased significantly during the washout period (Bierenbaum et al., 1993). Another study investigated nutritional properties in humans ingesting high-alpha-linolenic acid flaxseed. Healthy female volunteers consumed test meals containing 50 g ground, raw flaxseed/day for four weeks, which provided 12–13% of energy intake (24–25 g/100 g total fat). The study concluded that up to 50 g high-alpha-linolenic acid flaxseed/day is palatable, safe, and may be nutritionally beneficial in humans by raising long chain n-3 fatty acids in plasma and erythrocytes and by decreasing postprandial glucose responses. The flaxseed supplementation also lowered serum total cholesterol by 9% and LDL cholesterol by 18% (Cunnane et al., 1993). Pharmacopeial grade flaxseed is not presently defined on the basis of a specific chemical composition, but rather on a number of identity and quality tests, including organoleptic evaluation, macroscopic and microscopic authentication, and certain quantitative standards. For example, its swelling index should be not less than 4 for the whole seed and 4.5 for the powdered seed (Bruneton, 1995; Ph.Eur.3, 1997; Ph.Fr.X, 1990; Tu, 1992; Wichtl and Bisset, 1994).
Description
Flaxseed consists of the dried, ripe seed of the collective variations of Linum usitatissimum L. [Fam. Linaceae], as well as its preparations in effective dosage. The cultivars of L. usitatissimum (L.) Vav. et Ell. are equally acceptable for the indications listed in this monograph. The seeds contain: fiber (hemicellulose, cellulose, and lignin), fatty oil with 52–76% linolenic acid esters, albumin, linustatin, and linamarin.
Chemistry and Pharmacology
Flaxseed contains fixed oil (30–45%); triglycerides of linolenic, linoleic, oleic, stearic, palmitic, and myristic acids; proteins (20–25%); mucilage (3–10%), composed of neutral and acidic polysaccharides which after hydrolysis yield galactose (8–10%), arabinose (9–12%), rhamnose (13–29%), xylose (25–27%), and galacturonic and mannuronic acids (approx. 30%); sterols and triterpenes (cholesterol, campesterol, stigmasterol, and sitosterol); cyanogenic glycosides (0.1–1.5%), mostly linustatin and neolinustatin and the monoglycosides linamarin and lotaustralin; and secoisolariciresinol glycoside (a precursor of lignans in mammals) (Bruneton, 1995; Budavari, 1996; ESCOP, 1997; Wichtl and Bissett, 1994). The Commission E reported laxative effects due to increase in volume and consequent initiation of intestinal peristalsis due to stretching reflexes. A protective effect on the mucosa has been observed because of flaxseed's coating action. The British Herbal Pharmacopoeia reported its actions as bulk-forming laxative and demulcent (BHP, 1996). A decrease in transit time and increase of stool weight in patients suffering from constipation was demonstrated in two multicentric studies (ESCOP, 1997). Linseed binds with water and swells to form a demulcent gel in the intestine, thus softening the feces and increasing the volume of the bowel content (ESCOP, 1997). In a recent overview of clinical trials, flaxseed's high levels of a-linolenic acid, an essential fatty acid, and the lignan secoisolariciresinol diglucoside (SDG) are suggested as anti-carcinogenic and as beneficial in treating systemic lupus erythematosus (SLE), hyperlipidemia, and perhaps malaria and rheumatoid arthritis. Flaxseed contains more (between 75 and 800 times) of the beneficial phytochemical SDG when compared to other food sources (Haggerty, 1999).
Uses
The Commission E approved the internal use of flaxseed for chronic constipation, for colons damaged by abuse of laxatives, irritable colon, diverticulitis, and as mucilage for gastritis and enteritis. External use is approved as a cataplasm for local inflammation. ESCOP reports its internal use for constipation, irritable bowel syndrome, diverticular disease and for symptomatic short-term treatment of gastritis and enteritis, and external use for painful skin inflammations (ESCOP, 1997). The German Standard License for whole or freshly crushed linseed lists it as a bulk laxative for the treatment of constipation and functional bowel complaints (irritable colon) and as a demulcent preparation for the supportive treatment of inflammatory gastrointestinal complaints (Wichtl and Bisset, 1994). The Merck Index indicates its use externally as an emollient (Budavari, 1996). Its mucilage content justifies its use like psyllium seed, as an adjunctive therapy for pains related to spasmodic colitis (Bruneton, 1995). Popular herbal use of flaxseed includes coughs, sore throats, hardening of the arteries, and rheumatoid arthritis. External indications include abscesses, ulcers, and, when mixed with white mustard seeds, a poultice for chest complaints (Bown, 1995).
Contraindications
Ileus of any origin.
Side Effects
If directions are observed, i.e., especially if the concomitant administration of sufficient amounts of liquid (1:10) is observed, there are no known side effects.
Use During Pregnancy and Lactation
No restrictions known.
Interactions with Other Drugs
As with any other mucilage, the absorption of other drugs may be negatively affected.
Dosage and Administration
Internal: Unless otherwise prescribed: As seed, as cracked or coarsely ground seed, in which only the cuticle and mucilage epidermis are damaged; as flaxseed mucilage (gruel) and other galenical preparations. Bruised or whole seed: Take 1 tablespoon whole or 'bruised' seed (not ground) with 150 ml of liquid two to three times daily. [Note: 1 tablespoon = 10 g seed].
Mucilage (gruel): Soak 2-3 tablespoons of milled flaxseed in 200-300 ml water, strain after 30 minutes. External: Unless otherwise prescribed: As flaxseed flour or flaxseed expellent. Cataplasm: Semi-solid paste containing 30-50 g flaxseed flour for a moist-heat direct application to the skin used like a poultice as a counterirritant drawing blood to the surface to remove deep-seated inflammation. Note: Flaxseed meal is traditionally mixed with mustard seed powder in this application.
Compress or fomentation: Saturate a stupe with hot semi-solid preparation containing 30-50 g flaxseed flour; fold and apply firmly for a moist-heat direct application to the skin to relieve pain or inflammation.
References
Allman, M.A., M.M. Pena, D. Pang. 1995. Supplementation with flaxseed oil versus sunflowerseed oil in healthy young men consuming a low fat diet: effects on platelet composition and function. Eur J Clin Nutr 49(3):169178. Bierenbaum, M.L., R. Reichstein, T.R. Watkins. 1993. Reducing atherogenic risk in hyperlipemic humans with flax seed supplementation: a preliminary report. J Am Coll Nutr 12(5):501504. Bown, D. 1995. Encyclopedia of Herbs and Their Uses. New York: DK Publishing, Inc. 304. British Herbal Pharmacopoeia (BHP). 1996. Exeter, U.K.: British Herbal Medicine Association. Bruneton, J. 1995. Pharmacognosy, Phytochemistry, Medicinal Plants. Paris: Lavoisier Publishing. Budavari, S. (ed.). 1996. The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals, 12th ed. Whitehouse Station, N.J.: Merck & Co, Inc. Carlson, C. 1998. The Benefits of Flax. Herbs for Health Sept/Oct:6365. Clark, W.F. et al. 1995. Flaxseed: A potential treatment of lupus nephritis. Kidney Int 48(2):475480. Cunnane, S.C. et al. 1993. High alpha-linolenic acid flaxseed (Linum usitatissimum): some nutritional properties in humans. Br J Nutr 69(2):443453. ESCOP. 1997. 'Lini semen.' Monographs on the Medicinal Uses of Plant Drugs. Exeter, U.K.: European Scientific Cooperative on Phytotherapy. Europäisches Arzneibuch, 3rd ed. (Ph.Eur.3). 1997. Stuttgart: Deutscher Apotheker Verlag. Grieve, M. 1979. A Modern Herbal. New York: Dover Publications, Inc. Haggerty, W. 1999. Flax:Ancient Herb and Modern Medicine.HerbalGram 45:5156. Kapoor, L.D. 1990. Handbook of Ayurvedic Medicinal Plants. Boca Raton: CRC Press. 217. Karnick, C.R. 1994. Pharmacopoeial Standards of Herbal Plants, Vols. 12. Delhi: Sri Satguru Publications. Vol. 1:228229; Vol. 2:55 Nadkarni, K.M. 1976. Indian Materia Medica. Bombay: Popular Prakashan. 743746. Nestel, P.J. et al. 1997. Arterial compliance in obese subjects is improved with dietary plant n-3 fatty acid from flaxseed oil despite increased LDL oxidizability. Arterioscler Thromb Vasc Biol 17(6):11631170. Ph.Eur.3. See Europäisches Arzneibuch. Pharmacope Franaise Xe dition (Ph.Fr.X.). 19831990. Moulins-les-Metz: Maisonneuve S.A. Serraino, M. and L.U. Thompson. 1991. The effect of flaxseed supplementation on early risk markers for mammary carcinogenesis. Cancer Lett 60(2):135142. . 1992a. The effect of flaxseed supplementation on the initiation and promotional stages of mammary tumorigenesis. Nutr Cancer 17(2):153159. . 1992b. Flaxseed supplementation and early markers of colon carcinogenesis. Cancer Lett 63(2):159165. Taber, C.W. 1962. Taber's Cyclopedic Medical Dictionary, 9th ed. Philadelphia: F.A. Davis Company. F-21. Tu, G. (ed.). 1992. Pharmacopoeia of the People's Republic of China (English Edition 1992). Beijing: Guangdong Science and Technology Press. Wichtl, M. and N.G. Bisset (eds.). 1994. Herbal Drugs and Phytopharmaceuticals. Stuttgart: Medpharm Scientific Publishers. Yen, K.Y. 1992. The Illustrated Chinese Materia MedicaCrude and Prepared. Taipei: SMC Publishing, Inc. 174.
Additional Resources
Cunnane, S.C. et al. 1995. Nutritional attributes of traditional flaxseed in healthy young adults. Am J Clin Nutr 61(1):6268. Gilman, A.G., T.W. Rall, A.S. Nies, P. Taylor (eds.). 1990. The Pharmacological Basis of Therapeutics. New York: Pergamon Press. 915918. Jenab, M. and L.U. Thompson. 1996. The influence of flaxseed and lignans on colon carcinogenesis and beta-glucuronidase activity. Carcinogenesis 17(6):13431348. Jens, R., R. Nitsch-Fitz, H. Wutzl, H. Maruna. 1981. Ergebnisse einer Praxisstudie mit einer Leinsamen-Kombination zur Behebung der chronischen Obstipation bei 114 Patienten aus dem Raum Wien. Der Praktische Arzt 35:80. Kurth, W. 1976. Therapeutische Wirksamkeit, Vertrglichkeit und Akzeptabilitt von Linusit in der Praxis. Der Kassenarzt 16:3546. McGuffin, M., C. Hobbs, R. Upton, A. Goldberg. 1997. American Herbal Product Association's Botanical Safety Handbook. Boca Raton: CRC Press. Obermeyer, W.R., C. Warner, R.E. Casey, S.M. Musser. 1993. Flaxseed lignans. Isolation, metabolism and biological effects (Abstract 4985). Experimental Biol 93. Obermeyer, W.R. et al. 1995. Chemical studies of phytoestrogens and related compounds in dietary supplements: flax and chaparral (43824). Proc Soc Exp Biol Med 208(1):612. Reynolds, J.E.F. (ed.). 1993. Martindale: The Extra Pharmacopoeia, 30th ed. London: The Pharmaceutical Press. 886. Schilcher, H. 1979. Zyanidvergiftung durch Leinssamen? Dtsch rtzteblatt 76:955956. Schilcher, H. and A. Nissler. 1980. Pflanzliche leihre Analytik und ditetische Verwendung. Phys Med u Reh 21:141156. Schilcher, H, V. Schulz, A. Nissler. 1986. Zur Wirksamkeit und Toxikologie von Semen Lini. Z Phytotherapie 7:113117. Schilcher, H. and M. Wilkens-Sauter. 1986. Quantitative Bestimmung cyanogener Glykoside in Linum usitatissimum mit Hilfe der HPLC. Fette Seifen Anstrichmittel 88:287290. Steinegger, E. and R. Hnsel. 1988. Lehrbuch der Pharmakognosie und Phytopharmazie, 4th ed. Berlin-Heidelberg: Springer Verlag.128129. Thompson, L.U., P. Robb, M. Serraino, F. Cheung. 1991. Mammalian lignan production from various foods. Nutr Cancer 16(1):4352. Thompson, L.U. et al. 1996. Flaxseed and its lignan and oil components reduce mammary tumor growth at a late stage of carcinogenesis. Carcinogenesis 17(6):13731376. Trease, G.E. and W.C. Evans. 1989. Trease and Evans' Pharmacognosy, 13th ed. London; Philadelphia: Baillire Tindall. 336. Wagner, H., W. Budweg, M.A. Iyengar, O. Volk, M. Sinn. 1972. Linosid A und B, zwei neue flavon-C-glykoside aus Linum maritimum [Linoside A and B, two new flavone-C-glycosides from Linum maritimum L]. Z Naturforsch B 27(7):809812. Wagner, H. 1980. Pharmazeutische Biologie, Vol. 2. Drogen und ihre Inhaltsstoffe. Stuttgart-New York: Gustav Fischer. 261262. Weiss, R.F. 1991. Lehrbuch der Phytotherapie, 7th ed. Stuttgart: Hippokrates.131133. Weiss, S.G., M. Tin-Wa, R.E. Perdue, N.R. Farnsworth. 1975. Potential anticancer agents II: antitumor and cytotoxic lignans from Linum album (Linaceae). J Pharm Sci 64(1):9598. Willuhn, G. 1989. Teedrogen, 2nd ed. Stuttgart: Wissenschaftliche Verlagsgesellschaft. 306308. Yan, L., J.A. Yee, D. Li, M.H. McGuire, L.U. Thompson. 1998. Dietary flaxseed supplementation and experimental metastasis of melanoma cells in mice. Cancer Lett 124(2):181186. This material was adapted from The Complete German Commission E MonographsTherapeutic Guide to Herbal Medicines. M. Blumenthal, W.R. Busse, A. Goldberg, J. Gruenwald, T. Hall, C.W. Riggins, R.S. Rister (eds.) S. Klein and R.S. Rister (trans.). 1998. Austin: American Botanical Council; Boston: Integrative Medicine Communications.
1) The Overview section is new information. 2) Description, Chemistry and Pharmacology, Uses, Contraindications, Side Effects, Interactions with Other Drugs, and Dosage sections have been drawn from the original work. Additional information has been added in some or all of these sections, as noted with references. 3) The dosage for equivalent preparations (tea infusion, fluidextract, and tincture) have been provided based on the following example: - Unless otherwise prescribed: 2 g per day of [powdered, crushed, cut or whole] [plant part]
- Infusion: 2 g in 150 ml of water
- Fluidextract 1:1 (g/ml): 2 ml
- Tincture 1:5 (g/ml): 10 ml
4) The References and Additional Resources sections are new sections. Additional Resources are not cited in the monograph but are included for research purposes. This monograph, published by the Commission E in 1994, was modified based on new scientific research. It contains more extensive pharmacological and therapeutic information taken directly from the Commission E.
Excerpt from Herbal Medicine: Expanded Commission E Monographs
Copyright 2000 American Botanical Council
Published by Integrative Medicine Communications
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