antinutrient

Phytic acid has a strong binding affinity to minerals such as calcium, magnesium, iron, copper, and zinc. This results in precipitation, making the minerals unavailable for absorption in the intestines.{{cite journal | first1 = Päivi | last1 = Ekholm | first2 = Liisa | last2 = Virkki | first3 = Maija | last3 = Ylinen | first4 = Liisa | last4 = Johansson | name-list-style = vanc |title=The effect of phytic acid and some natural chelating agents on the solubility of mineral elements in oat bran |journal=Food Chemistry |date=Feb 2003 |volume=80 |issue=2 |pages=165–70 |doi=10.1016/S0308-8146(02)00249-2}}{{cite journal | vauthors = Cheryan M | title = Phytic acid interactions in food systems | journal = Critical Reviews in Food Science and Nutrition | volume = 13 | issue = 4 | pages = 297–335 | year = 1980 | pmid = 7002470 | doi = 10.1080/10408398009527293 }} Phytic acids are common in the hulls of nuts, seeds, and grains and of great importance in agriculture, animal nutrition, and in eutrophication, due to the mineral chelation and bound phosphates released into the environment. Without the need to use milling to reduce phytate (including nutrient),{{cite journal | vauthors = Bohn L, Meyer AS, Rasmussen SK | title = Phytate: impact on environment and human nutrition. A challenge for molecular breeding | journal = Journal of Zhejiang University Science B | volume = 9 | issue = 3 | pages = 165–91 | date = March 2008 | pmid = 18357620 | pmc = 2266880 | doi = 10.1631/jzus.B0710640 }} the amount of phytic acid is commonly reduced in animal feeds by adding histidine acid phosphate type of phytases to them.{{cite journal | vauthors = Kumar V, Singh G, Verma AK, Agrawal S | title = In silico characterization of histidine Acid phytase sequences | journal = Enzyme Research | volume = 2012 | pages = 845465 | date = 2012 | pmid = 23304454 | pmc = 3523131 | doi = 10.1155/2012/845465 | doi-access = free }}

Oxalic acid and oxalates are present in many plants and in significant amounts particularly in rhubarb, tea, spinach, parsley, and purslane. Oxalates bind to calcium, magnesium and iron, preventing their absorption in the human body.{{cite journal|vauthors=Dolan LC, Matulka RA, Burdock GA|date=September 2010|title=Naturally occurring food toxins|journal=Toxins|volume=2|issue=9|pages=2289–332|doi=10.3390/toxins2092289|pmc=3153292|pmid=22069686|doi-access=free}}

Glucosinolates prevent the uptake of iodine, affecting the function of the thyroid and thus are considered goitrogens. They are found in plants such as broccoli, Brussels sprouts, cabbage, mustard greens, radishes, and cauliflower.

Protease inhibitors are substances that inhibit the actions of trypsin, pepsin, and other proteases in the gut, preventing the digestion and subsequent absorption of protein. For example, Bowman–Birk trypsin inhibitor is found in soybeans.{{cite journal | first1 = Anna L. | last1 = Tan-Wilson | first2 = Jean C. | last2 = Chen | first3 = Michele C. | last3 = Duggan | first4 = Cathy | last4 = Chapman | first5 = R. Scott | last5 = Obach | first6 = Karl A. | last6 = Wilson | name-list-style = vanc |title=Soybean Bowman-Birk trypsin isoinhibitors: classification and report of a glycine-rich trypsin inhibitor class |journal=J. Agric. Food Chem. |year=1987 |volume=35 |issue=6 |page=974 |doi=10.1021/jf00078a028}} Some trypsin inhibitors and lectins are found in legumes and interfere with digestion.{{cite journal|vauthors=Gilani GS, Cockell KA, Sepehr E|date=May 2005|title=Effects of antinutritional factors on protein digestibility and amino acid availability in foods|journal=Journal of AOAC International|volume=88|issue=3|pages=967–87|doi=10.1093/jaoac/88.3.967|pmid=16001874|doi-access=free}}

Lipase inhibitors interfere with enzymes, such as human pancreatic lipase, that catalyze the hydrolysis of some lipids, including fats. For example, the anti-obesity drug orlistat causes a percentage of fat to pass through the digestive tract undigested.{{cite journal | vauthors = Heck AM, Yanovski JA, Calis KA | title = Orlistat, a new lipase inhibitor for the management of obesity | journal = Pharmacotherapy | volume = 20 | issue = 3 | pages = 270–9 | date = March 2000 | pmid = 10730683 | pmc = 6145169 | doi = 10.1592/phco.20.4.270.34882 }}

Amylase inhibitors prevent the action of enzymes that break the glycosidic bonds of starches and other complex carbohydrates, preventing the release of simple sugars and absorption by the body. Like lipase inhibitors, they have been used as a diet aid and obesity treatment. They are present in many types of beans; commercially available amylase inhibitors are extracted from white kidney beans.{{cite journal | vauthors = Preuss HG | title = Bean amylase inhibitor and other carbohydrate absorption blockers: effects on diabesity and general health | journal = Journal of the American College of Nutrition | volume = 28 | issue = 3 | pages = 266–76 | date = June 2009 | pmid = 20150600 | doi = 10.1080/07315724.2009.10719781 | s2cid = 20066629 }}

Hypoglycin A, which is contained in lychees and ackee fruit, blocks the fatty acid metabolism, so that the body uses its glycogen deposits for energy, which can cause hypoglycemia, when these fruit are eaten in large quantities or as the sole diet.

Coprine found in some edible mushrooms, for example the common inkcap, inhibits the aldehyde dehydrogenase, which is a part of the alcohol digestive system. This can cause a buildup of the toxic acetaldehyde. Therefore, mushrooms containing coprine should never be consumed together with alcoholic beverages.

Excessive intake of required nutrients can also result in them having an anti-nutrient action. Excessive intake of dietary fiber can reduce the transit time through the intestines to such a degree that other nutrients cannot be absorbed. However, this effect is often not seen in practice and reduction of absorbed minerals can be attributed mainly to the phytic acids in fibrous food.{{Cite news|url=http://lpi.oregonstate.edu/mic/other-nutrients/fiber|title=Fiber|date=2014-04-28|work=Linus Pauling Institute|access-date=2018-04-15|archive-url=https://web.archive.org/web/20180414180232/http://lpi.oregonstate.edu/mic/other-nutrients/fiber|archive-date=2018-04-14|url-status=live|language=en}}{{cite journal | vauthors = Coudray C, Demigné C, Rayssiguier Y | title = Effects of dietary fibers on magnesium absorption in animals and humans | journal = The Journal of Nutrition | volume = 133 | issue = 1 | pages = 1–4 | date = January 2003 | pmid = 12514257 | doi = 10.1093/jn/133.1.1 | doi-access = free }} Foods high in calcium eaten simultaneously with foods containing iron can decrease the absorption of iron via an unclear mechanism involving iron transport protein hDMT1, which calcium can inhibit.{{cite journal | vauthors = Scheers N | title = Regulatory effects of Cu, Zn, and Ca on Fe absorption: the intricate play between nutrient transporters | journal = Nutrients | volume = 5 | issue = 3 | pages = 957–70 | date = March 2013 | pmid = 23519291 | pmc = 3705329 | doi = 10.3390/nu5030957 | doi-access = free }}

Avidin is an antinutrient found in active form in raw egg whites. It binds very tightly to biotin (vitamin B₇){{cite journal|vauthors=Miranda JM, Anton X, Redondo-Valbuena C, Roca-Saavedra P, Rodriguez JA, Lamas A, Franco CM, Cepeda A|date=January 2015|title=Egg and egg-derived foods: effects on human health and use as functional foods|journal=Nutrients|volume=7|issue=1|pages=706–29|doi=10.3390/nu7010706|pmc=4303863|pmid=25608941|doi-access=free}} and can cause deficiency of B₇ in animals{{cite journal|vauthors=Poissonnier LA, Simpson SJ, Dussutour A|date=2014-11-13|title=Observations of the "egg white injury" in ants|journal=PLOS ONE|volume=9|issue=11|pages=e112801|bibcode=2014PLoSO...9k2801P|doi=10.1371/journal.pone.0112801|pmc=4231089|pmid=25392989|doi-access=free}} and, in extreme cases, in humans.{{cite journal|vauthors=Baugh CM, Malone JH, Butterworth CE|date=February 1968|title=Human biotin deficiency. A case history of biotin deficiency induced by raw egg consumption in a cirrhotic patient|journal=The American Journal of Clinical Nutrition|volume=21|issue=2|pages=173–82|doi=10.1093/ajcn/21.2.173|pmid=5642891}}

A widespread form of antinutrients, the flavonoids, are a group of polyphenolic compounds that include tannins.{{cite journal | vauthors = Beecher GR | title = Overview of dietary flavonoids: nomenclature, occurrence and intake | journal = The Journal of Nutrition | volume = 133 | issue = 10 | pages = 3248S–3254S | date = October 2003 | pmid = 14519822 | doi = 10.1093/jn/133.10.3248S | url = http://jn.nutrition.org/cgi/pmidlookup?view=long&pmid=14519822 | doi-access = free }} These compounds chelate metals such as iron and zinc and reduce the absorption of these nutrients,{{cite journal | vauthors = Karamać M | title = Chelation of Cu(II), Zn(II), and Fe(II) by tannin constituents of selected edible nuts | journal = International Journal of Molecular Sciences | volume = 10 | issue = 12 | pages = 5485–97 | date = December 2009 | pmid = 20054482 | pmc = 2802006 | doi = 10.3390/ijms10125485 | doi-access = free }} and they also inhibit digestive enzymes and may also precipitate proteins.{{cite journal | vauthors = Adamczyk B, Simon J, Kitunen V, Adamczyk S, Smolander A | title = Tannins and Their Complex Interaction with Different Organic Nitrogen Compounds and Enzymes: Old Paradigms versus Recent Advances | journal = ChemistryOpen | volume = 6 | issue = 5 | pages = 610–614 | date = October 2017 | pmid = 29046854 | pmc = 5641916 | doi = 10.1002/open.201700113 }}

Saponins in plants may act like antifeedants{{cite journal | vauthors = Moses T, Papadopoulou KK, Osbourn A | title = Metabolic and functional diversity of saponins, biosynthetic intermediates and semi-synthetic derivatives | journal = Critical Reviews in Biochemistry and Molecular Biology | volume = 49 | issue = 6 | pages = 439–62 | date = 2014 | pmid = 25286183 | pmc = 4266039 | doi = 10.3109/10409238.2014.953628 }}{{cite journal | vauthors = Sparg SG, Light ME, van Staden J | title = Biological activities and distribution of plant saponins | journal = Journal of Ethnopharmacology | volume = 94 | issue = 2–3 | pages = 219–43 | date = October 2004 | pmid = 15325725 | doi = 10.1016/j.jep.2004.05.016 }} and can be classified as antinutrients.{{cite journal | vauthors = Difo VH, Onyike E, Ameh DA, Njoku GC, Ndidi US | title = Changes in nutrient and antinutrient composition of Vigna racemosa flour in open and controlled fermentation | journal = Journal of Food Science and Technology | volume = 52 | issue = 9 | pages = 6043–8 | date = September 2015 | pmid = 26345026 | pmc = 4554638 | doi = 10.1007/s13197-014-1637-7 }}

Antinutrients are found at some level in almost all foods for a variety of reasons. However, their levels are reduced in modern crops, probably as an outcome of the process of domestication.{{cite web|title=Plant Toxins and Antinutrients |author=GEO-PIE Project |publisher=Cornell University |url=http://www.geo-pie.cornell.edu/issues/toxins.html |url-status=dead |archive-url=https://web.archive.org/web/20080612160331/http://www.geo-pie.cornell.edu/issues/toxins.html |archive-date=June 12, 2008 }} The possibility now exists to eliminate antinutrients entirely using genetic engineering; but, since these compounds may also have beneficial effects, such genetic modifications could make the foods more nutritious, but not improve people's health.{{cite journal | vauthors = Welch RM, Graham RD | title = Breeding for micronutrients in staple food crops from a human nutrition perspective | journal = Journal of Experimental Botany | volume = 55 | issue = 396 | pages = 353–64 | date = February 2004 | pmid = 14739261 | doi = 10.1093/jxb/erh064 | doi-access = free }}

Many traditional methods of food preparation such as germination, cooking, fermentation, and malting increase the nutritive quality of plant foods through reducing certain antinutrients such as phytic acid, polyphenols, and oxalic acid.{{cite journal | vauthors = Hotz C, Gibson RS | title = Traditional food-processing and preparation practices to enhance the bioavailability of micronutrients in plant-based diets | journal = The Journal of Nutrition | volume = 137 | issue = 4 | pages = 1097–100 | date = April 2007 | pmid = 17374686 | doi = 10.1093/jn/137.4.1097 | url = http://jn.nutrition.org/cgi/pmidlookup?view=long&pmid=17374686 | doi-access = free }} Such processing methods are widely used in societies where cereals and legumes form a major part of the diet.{{cite journal | vauthors = Chavan JK, Kadam SS | title = Nutritional improvement of cereals by fermentation | journal = Critical Reviews in Food Science and Nutrition | volume = 28 | issue = 5 | pages = 349–400 | year = 1989 | pmid = 2692608 | doi = 10.1080/10408398909527507 }}{{cite journal | vauthors = Phillips RD | title = Starchy legumes in human nutrition, health and culture | journal = Plant Foods for Human Nutrition | volume = 44 | issue = 3 | pages = 195–211 | date = November 1993 | pmid = 8295859 | doi = 10.1007/BF01088314 | s2cid = 24735125 }} An important example of such processing is the fermentation of cassava to produce cassava flour: this fermentation reduces the levels of both toxins and antinutrients in the tuber.{{cite journal | vauthors = Oboh G, Oladunmoye MK | title = Biochemical changes in micro-fungi fermented cassava flour produced from low- and medium-cyanide variety of cassava tubers | journal = Nutrition and Health | volume = 18 | issue = 4 | pages = 355–67 | year = 2007 | pmid = 18087867 | doi = 10.1177/026010600701800405 | s2cid = 25650282 }}

• Antimetabolite
• Biopesticide
• Plant defense against herbivory

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• {{cite book |author=Shahidi, Fereidoon |title=Antinutrients and phytochemicals in food |publisher=American Chemical Society |location=Columbus, OH |year=1997 |isbn=0-8412-3498-1}}