Ground Flaxseed – How Safe is it for Companion Animals and for Us?

Updata:01-01-1970

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By:Michael Ivan Lindinger

DOI: https://doi.org/10.30564/vsr.v1i1.1158

Abstract:

EFSA released the 89-page Scientific Opinion “Evaluation of the health risks related to the presence of cyanogenic glycosides in foods other than raw apricot kernels”. This opinion, and the ensuring media coverage, has left uncertainty in the minds of consumers, feed and supplement manufacturers and flaxseed producers of how much ground flaxseed can safely be consumed without crossing the threshold of cyanide toxicity. This editorial updates the science and tries to bring clarity to the question “how much flaxseed can I safely feed my dog, cat, horse on a daily basis?” and “how much can I safely eat?” The great majority of ground flaxseed products have a cyanogenic glycoside content of less than 200 mg / kg seed. For people, consuming 30 grams of such flaxseed the average peak blood cyanide concentration will be about 5 µmole / L, much less than the toxic threshold value of 20 to 40 µmole / L favoured by EFSA.  Thus, as much as 120 grams of crushed / ground flaxseed can be consumed by a 70 kg adult person before a toxic threshold of 40 µmole / L is reached (up to 1.7 grams ground flaxseed / kg body weight). The toxic threshold of cyanide for dogs is 2 to 4-fold greater than for humans, and unknown for cats and horses. The daily serving amounts for dogs and cats are about 0.23 grams / kg body mass per day, which will result in blood cyanide well below the toxic threshold. The highest recommended daily serving amount for horses is 454 grams per day, or 0.8 to 2 grams per kg / body mass depending on mass of the horse. This amount for horses should not be exceeded.

References:

[1] Abraham K, Buhrke T and Lampen A. Bioavailability of cyanide after consumption of a single meal of foods containing high levels of cyanogenic glycosides: a crossover study in humans. Archives of Toxicology, 2016, 90: 559–574. [2] Barthlet VJ and Bacala R. Development of optimized extraction methodology for cyanogenic glycosides from flaxseed (Linum usitatissimum). Journal of AOAC International, 2010, 93: 478-48. [3] Brimer L. Cyanogenic glycosides in food, feeding stuffs and green medicine. In: Bernhoft A (ed.) Bioactive compounds in plants – benefits and risks for man and animals. The Norwegian Academy of Science and Letters, Oslo, 2010: 125-143, ISBN: 978-82-7099-583-7 [4] Cressey P, Reeve J.Metabolism of cyanogenic glycosides: A review. Food Chem Toxicol, 2019, 125: 225-232. DOI:https://doi.org/10.1016/j.fct.2019.01.002 [5] Dunbar BL, Bigley KE, Bauer JE. Early and sustained enrichment of serum n-3 long chain polyunsaturated fatty acids in dogs fed a flaxseed supplemented diet. Lipids, 2010, 45: 1-10. [6] FAO/WHO (Food and Agricultural Organization/World Health Organization). Discussion paper on cyanogenic glycosides. Rome, Italy, Food and Agriculture Organization of the United Nations and World Health Organization, Joint FAO/ WHO Food Standards Programme, Codex Alimentarius Commission, Codex Committee on Contaminants in Foods, 2008. (CX/CF 09/3/11). [7] Feng D, Shen Y, Chavez ER. Effectiveness of different processing methods in reducing hydrogen cyanide content of flaxseed. J Sci Food Agric, 2003, 83: 836-841. [8] FSANZ (Food Standards Australia New Zealand). Survey of cyanogenic glycosides in plant-based foods in Australia and New Zealand, 2014, 13: 1–78. [9] Hall AH, Rumack BH. Clinical toxicology of cyanide. Ann Emerg Med, 1986, 15(9): 1067-74. [10] Hess TM, Rexford JK, Hansen DK, Harris M, Schauermann N, Ross T, Engle TE, Allen KG, Mulligan CM. Effects of two different dietary sources of long chain omega-3, highly unsaturated fatty acids on incorporation into the plasma, red blood cell, and skeletal muscle in horses. J Anim Sci., 2012, 90(9): 3023-31. DOI:https://doi.org/10.2527/jas.2011-4412 [11] Janickie, KM. 5 facts about flax. Thehorse.com, 2019. https://thehorse.com/148473/5-facts-about-flax [12] Kempe R, Saastamoinen M. Effect of linseed cake supplementation on digestibility and faecal and haematological parameters in dogs. J Anim Physiol Anim Nutr, 2007, 91: 319-325. [13] Lans C, Turner N, Brauer G, Khan T. Medicinal plants used in British Columbia, Canada for reproductive health in pets. Prev Vet Med, 2009, 90: 268-273. [14] Mueller RS, Fettman MJ, Richardson K, Hansen RA, Miller A, Magowitz J, Ogilvie GK. Plasma and skin concentrations of polyunsaturated fatty acids before and after supplementation with n-3 fatty acids in dogs with atopic dermatitis. Am J Vet Res. 2005, 66(5): 868-73. [15] Mueller RS, Fieseler KV, Fettman MJ, Zabel S, Rosychuk RAW, Ogilvie GK, Greenwalt TL. Effect of omega-3 fatty acids on canine atopic dermatitis. J Small Anim Pract, 2004, 45: 293-297. [16] O'Neill W, McKee S, Clarke AF. Flaxseed (Linum usitatissimum) supplementation associated with reduced skin test lesional area in horses with Culicoides hypersensitivity. Can J Vet Res. 2002, 66(4): 272-7. [17] Park HJ, Park JS, Hayek MG, Reinhart GA, Chew BP. Dietary fish oil and flaxseed oil suppress inflammation and immunity in cats. Vet Immunol Immunopathol. 2011, 141(3-4): 301-6. DOI:https://doi.org/10.1016/j.vetimm.2011.02.024 [18] Patoux S, Istasse L. Incorporation of sunflower oil or linseed oil in equine compound feedstuff: 1 Effects on haematology and on fatty acids profiles in the red blood cells membranes. J Anim Physiol Anim Nutr (Berl). 2016, 100(5): 828-35. DOI:https://doi.org/10.1111/jpn.12448 [19] Rees CA, Bauer JE, Burkholder WJ, Kennis RA, Dunbar BL, Bigley KE. Effects of dietary flax seed and sunflower seed supplementation on normal canine serum polyunsaturated fatty acids and skin and hair coat condition. Vet Dermatol, 2001, 12: 111-117. [20] Rosling H. Cyanide exposure from linseed. Lancet. 1993, 41(8838): 177. [21] Swanson KS, Grieshop CM, Clapper GM, Shields Jr RG, Belay T, Merchen NR, Fahey Jr GC. Fruit and vegetable fiber fermentation by gut microflora from canines. J Anim Sci. 2001, 79: 919-926. [22] Vineyard KR, Warren LK, Kivipelto J. Effect of dietary omega-3 fatty acid source on plasma and red blood cell membrane composition and immune function in yearling horses. J Anim Sci. 2010, 88(1): 248-57. DOI:https://doi.org/10.2527/jas.2009-2253 [23] Wu CF, Xu XM, Huang SH, Deng MC, Feng AJ, Peng J, Yuan JP, Wang JH.An efficient fermentation method for the degradation of cyanogenic glycosides in flaxseed. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2012, 29(7): 1085-91. DOI:https://doi.org/10.1080/19440049.2012.680202 [24] Yamashita T, Sano T, Hashimoto T and Kanzawa K. Development of a method to remove cyanogenic glycosides from flaxseed meal. International Journal of Food Science and Technology, 2007, 42: 70-75. [25] Schulz V, Löffler A, Gheorghiu T. [Resorption of hydrocyanic acid from linseed].[Article in German] Leber Magen Darm. 1983, 13(1): 10-40.

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