View source for Psyllium

{{Short description|Plant used as a dietary fiber}}
{{For|the town of ancient Bithynia in Asia Minor|Psyllium (Bithynia)}}
{{Use American English|date=November 2024}}
{{Use mdy dates|date=November 2024}}
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[[File:Psyllium seed husk pile.JPG|alt=Psyllium Husk (Isbagol)|thumb|300px|Psyllium husk after processing]]
[[File:Plantago afra kz6.jpg|thumb|''Plantago afra,'' a member of the plant genus from which psyllium can be derived]]
'''Psyllium''' ({{IPAc-en|ˈ|s|ɪ|l|i|əm}}), or '''ispaghula''' ({{IPAc-en|ˌ|ɪ|s|p|ə|ˈ|ɡ|uː|l|ə}}), is the common name used for several members of the plant genus ''[[Plantago]]'' whose seeds are used commercially for the production of [[mucilage]]. Psyllium is mainly used as a dietary fiber to relieve symptoms of both [[constipation]] and mild [[diarrhea]], and occasionally as a [[food thickener]].<ref name="slavin13">{{cite journal | last=Slavin | first=Joanne | title=Fiber and prebiotics: Mechanisms and health benefits | journal=Nutrients | volume=5 | issue=4 | date=22 April 2013 | issn=2072-6643 | doi=10.3390/nu5041417 | pages=1417–1435|pmid=23609775|pmc=3705355| doi-access=free }}</ref> Allergy to psyllium is common in workers frequently exposed to the substance.
Use of psyllium in the diet for three weeks or longer may lower [[Blood lipids|blood cholesterol]] levels in people with elevated cholesterol,<ref name="williams">{{cite journal | last=Williams | first=Peter G. | title=The Benefits of Breakfast Cereal Consumption: A Systematic Review of the Evidence Base | journal=Advances in Nutrition | volume=5 | issue=5 | date=1 August 2014 | issn=2156-5376 | doi=10.3945/an.114.006247 | pages=636S–673S|pmid=25225349|pmc=4188247}}</ref><ref name="Jov">{{cite journal | last1=Jovanovski | first1=Elena | last2=Yashpal | first2=Shahen | last3=Komishon | first3=Allison | last4=Zurbau | first4=Andreea | last5=Blanco Mejia | first5=Sonia | last6=Ho | first6=Hoang Vi Thanh | last7=Li | first7=Dandan | last8=Sievenpiper | first8=John | last9=Duvnjak | first9=Lea | last10=Vuksan | first10=Vladimir | title=Effect of psyllium (''Plantago ovata'') fiber on LDL cholesterol and alternative lipid targets, non-HDL cholesterol and apolipoprotein B: a systematic review and meta-analysis of randomized controlled trials | journal=The American Journal of Clinical Nutrition | volume=108 | issue=5 | date=15 September 2018 | issn=0002-9165 | doi=10.1093/ajcn/nqy115 | pages=922–932|pmid=30239559| doi-access=free }}</ref> and may lower [[blood glucose]] levels in people with [[type 2 diabetes]].<ref name=Gibb2015/> Use of psyllium for a month or longer may produce a small reduction in [[systolic blood pressure]].<ref name="Khan">{{cite journal | last1=Khan | first1=K. | last2=Jovanovski | first2=E. | last3=Ho | first3=H.V.T. | last4=Marques | first4=A.C.R. | last5=Zurbau | first5=A. | last6=Mejia | first6=S.B. | last7=Sievenpiper | first7=J.L. | last8=Vuksan | first8=V. | title=The effect of viscous soluble fiber on blood pressure: A systematic review and meta-analysis of randomized controlled trials | journal=Nutrition, Metabolism and Cardiovascular Diseases| volume=28 | issue=1 | year=2018 | issn=0939-4753 | doi=10.1016/j.numecd.2017.09.007 | pages=3–13|pmid=29153856}}</ref>
The plants from which the seeds are extracted tolerate damp and cool climates, and are mainly cultivated in northern [[India]].
==Uses==
===Preparation===
Psyllium is produced mainly for its [[mucilage]] content. The term ''mucilage'' describes a group of clear, colorless, gelling agents derived from plants. The mucilage obtained from psyllium comes from the seed coat. Mucilage is obtained by mechanical milling (i.e. grinding) of the outer layer of the seed. Mucilage yield amounts to about 25% (by weight) of the total seed yield. Plantago-seed mucilage is often referred to as [[husk]], or psyllium husk. The milled seed mucilage is a white fibrous material that is [[hydrophilic]], meaning that its molecular structure causes it to attract and bind to water.<ref name="van der Schoot2022" /><ref name="Shahinfar2023">{{cite journal |last1=Shahinfar |first1=H |last2=Jayedi |first2=A |last3=Torabynasab |first3=K |last4=Payandeh |first4=N |last5=Martami |first5=F |last6=Moosavi |first6=H |last7=Bazshahi |first7=E |last8=Shab-Bidar |first8=S |title=Comparative effects of nutraceuticals on body weight in adults with overweight or obesity: A systematic review and network meta-analysis of 111 randomized clinical trials. |journal=Pharmacological Research |date=October 2023 |volume=196 |pages=106944 |doi=10.1016/j.phrs.2023.106944|pmid=37778464|doi-access=free }}</ref>
===Food===
Psyllium has been used as a [[thickener]] in ice cream and other frozen desserts. A 1.5% weight/volume ratio of psyllium mucilage exhibits binding properties that are superior to a 10% weight/volume ratio of starch mucilage.<ref name=":2">{{Cite journal |last1=Goto-Tamura |first1=R. |last2=Takesue |first2=Y. |last3=Takesue |first3=S. |date=1976-02-16 |title=Immunological similarity between NADH-cytochrome b5 reductase of erythrocytes and liver microsomes |journal=Biochimica et Biophysica Acta (BBA) - Bioenergetics |url=https://pubmed.ncbi.nlm.nih.gov/2319 |volume=423 |issue=2 |pages=293–302 |doi=10.1016/0005-2728(76)90186-9 |issn=0006-3002 |pmid=2319}}</ref> The [[viscosity]] of psyllium mucilage dispersions are relatively unaffected between temperatures of {{convert|20|and|50|C|F}}, by [[pH]] from 2 to 10, and by [[salt]] (sodium chloride) concentrations up to 0.15''&nbsp;''M.<ref name=":2" />
Psyllium seed husks can also be used to improve texture in [[gluten-free]] baked goods, to bind [[meatballs]], and to thicken sauces.<ref name="nyt">{{cite news |url=https://www.nytimes.com/2023/08/17/dining/psyllium-husks.html |title=A Centuries-Old Fiber Supplement Entices the Ozempic Generation |author=Priya Krishna |date=August 17, 2023 |newspaper=[[The New York Times]]}}</ref> Some people use them to manage symptoms of [[irritable bowel syndrome]].
===Human health===
==== Weight loss ====
[[Dietary supplement]]s containing psyllium are sold mainly to aid [[weight loss]], although there is little [[evidence-based medicine|scientific evidence]] for such effects.<ref name="Daroog">{{cite journal |last1=Darooghegi Mofrad |first1=Manije |last2=Mozaffari |first2=Hadis |last3=Mousavi |first3=Seyed Mohammad |last4=Sheikhi |first4=Ali |last5=Milajerdi |first5=Alireza |date=2019-03-18 |title=The effects of psyllium supplementation on body weight, body mass index and waist circumference in adults: A systematic review and dose-response meta-analysis of randomized controlled trials |journal=Critical Reviews in Food Science and Nutrition |volume=60 |issue=5 |pages=859–872 |doi=10.1080/10408398.2018.1553140 |issn=1040-8398 |pmid=30880409 |s2cid=81983941}}</ref>
A 2023 review concluded that psyllium supplementation for 12 weeks by people who were overweight or obese produced a minor amount of weight loss, although the studies assessed had only moderate to low evidence quality.<ref name="Shahinfar2023" />
====Constipation====
Psyllium is mainly used as a [[viscosity|viscous]], [[soluble]] [[dietary fiber]] that is not absorbed by the [[small intestine]].<ref name="mcr">{{cite journal | last1=McRorie | first1=Johnson W. | last2=McKeown | first2=Nicola M. | title=Understanding the Physics of Functional Fibers in the Gastrointestinal Tract: An Evidence-Based Approach to Resolving Enduring Misconceptions about Insoluble and Soluble Fiber | journal=Journal of the Academy of Nutrition and Dietetics | volume=117 | issue=2 | year=2017 | issn=2212-2672 | doi=10.1016/j.jand.2016.09.021 | pages=251–264| pmid=27863994 | doi-access=free }}</ref> The mechanical action of psyllium mucilage is to absorb excess water while stimulating normal bowel elimination.<ref name="Rao2021" /> Although its main use has been as a [[laxative]], it is more accurately regarded as a dietary fiber to reduce the symptoms of both constipation and mild [[diarrhea]].<ref name=mcr/><ref name="Rao2021" /> The laxative properties of psyllium are attributed to the fiber: it absorbs water and subsequently softens the stool.<ref name=mcr/><ref name="van der Schoot2022" /> It increases [[flatulence]] (gas) to some degree.<ref name="chris">{{Cite journal|last1=Christodoulides|first1=S.|last2=Dimidi|first2=E.|last3=Fragkos|first3=K. C.|last4=Farmer|first4=A. D.|last5=Whelan|first5=K.|last6=Scott|first6=S. M.|date=2016-07-01|title=Systematic review with meta-analysis: effect of fibre supplementation on chronic idiopathic constipation in adults|journal=Alimentary Pharmacology & Therapeutics|language=en|volume=44|issue=2|pages=103–116|doi=10.1111/apt.13662|pmid=27170558|s2cid=34178677|issn=1365-2036|url=http://qmro.qmul.ac.uk/xmlui/handle/123456789/14210|doi-access=free}}</ref> Psyllium reduces straining during defecation by increasing the bulk of stools, thereby facilitating the transit of stools in the colon.<ref name="van der Schoot2022" /> When used to treat constipation, psyllium is taken in doses of 3.5&ndash;11 grams per day twice daily.<ref name="Rao2021" />
A 2021 review of over-the-counter treatments for constipation concluded that psyllium has modest effect in treating constipation and is generally safe and well-tolerated.<ref name="Rao2021" /> Psyllium may be less effective compared to other products, such as [[polyethylene glycol]], [[lactulose]] or fruits like [[prune]]s.<ref name="Rao2021">{{cite journal |last1=Rao |first1=SSC |last2=Brenner |first2=DM |title=Efficacy and Safety of Over-the-Counter Therapies for Chronic Constipation: An Updated Systematic Review. |journal=The American Journal of Gastroenterology |date=1 June 2021 |volume=116 |issue=6 |pages=1156–1181 |doi=10.14309/ajg.0000000000001222 |pmid=33767108|pmc=8191753}}</ref> Psyllium is more effective than [[docusate]].<ref name="Rao2021" />
A 2022 review found that psyllium, in doses of 10 grams per day for at least 4 weeks, was more effective than osmotic or stimulant laxatives for increasing the number of bowel movements per week.<ref name="van der Schoot2022">{{cite journal |last1=van der Schoot |first1=A |last2=Drysdale |first2=C |last3=Whelan |first3=K |last4=Dimidi |first4=E |title=The Effect of Fiber Supplementation on Chronic Constipation in Adults: An Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials. |journal=The American Journal of Clinical Nutrition |date=6 October 2022 |volume=116 |issue=4 |pages=953–969 |doi=10.1093/ajcn/nqac184 |pmid=35816465 |pmc=9535527}}</ref>
====High blood cholesterol====
In 1998, the U.S. Food and Drug Administration approved a health claim on food labels for dietary psyllium as a [[Dietary fiber#Plant sources of fiber|soluble fiber]] &ndash; if consumed regularly &ndash; that would reduce the risk of [[heart disease]] by lowering [[blood cholesterol]].<ref name=FDA>[https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=101.81 Sec. 101.81 Health claims: Soluble fiber from certain foods and risk of coronary heart disease (CHD)] {{Webarchive|url=https://web.archive.org/web/20190523074447/https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=101.81 |date=2019-05-23 }} U.S. Food and Drug Administration, Code of Federal Regulations Title 21.</ref> Clinical research demonstrated that seven grams or more per day of soluble fiber from psyllium seed husk would sufficiently lower total [[cholesterol]] and [[low density lipoprotein]] cholesterol in people with [[hypercholesterolemia]], two accepted biomarkers for risk of [[coronary heart disease]].<ref>{{cite journal |vauthors=Olson BH, Anderson SM, Becker MP, Anderson JW, Hunninghake DB, Jenkins DJ, LaRosa JC, Rippe JM, Roberts DC, Stoy DB, Summerbell CD, Truswell AS, Wolever TM, Morris DH, Fulgoni VL |title=Psyllium-enriched cereals lower blood total cholesterol and LDL cholesterol, but not HDL cholesterol, in hypercholesterolemic adults: results of a meta-analysis |journal=J. Nutr. |volume=127 |issue=10 |pages=1973–80 |date=October 1997 |pmid=9311953 |doi= 10.1093/jn/127.10.1973|doi-access=free }}</ref> The findings were later confirmed in a [[meta-analysis]] that incorporated more evidence.<ref name=Wei2009>{{cite journal |vauthors=Wei ZH, Wang H, Chen XY, Wang BS, Rong ZX, Wang BS, Su BH, Chen HZ |title=Time- and dose-dependent effect of psyllium on serum lipids in mild-to-moderate hypercholesterolemia: a meta-analysis of controlled clinical trials |journal=Eur J Clin Nutr |volume=63 |issue=7 |pages=821–827 |date=July 2009 |pmid=18985059 |doi=10.1038/ejcn.2008.49 |s2cid=205129609 |doi-access=free }}</ref> To be eligible for the FDA-allowed health claim, one serving of a manufactured food or [[dietary supplement]] must contain at least 1.7 g of psyllium as soluble fiber.<ref name=FDA /> [[Whole grain|Whole oats]], [[barley]] and foods containing [[beta-glucan]] soluble fiber were included as eligible sources for the label claim.<ref name=FDA />
====Type 2 diabetes====
In 2014, the U.S. Food and Drug Administration approved a qualified health claim for psyllium as a possible benefit for people with [[diabetes]], requiring FDA-approved wording on a product label: "Psyllium husk may reduce the risk of type 2 diabetes, although the FDA has concluded that there is very little scientific evidence for this claim."<ref>[https://www.fda.gov/downloads/Food/IngredientsPackagingLabeling/LabelingNutrition/UCM403090.pdf Qualified Health Claim for Diabetes] {{Webarchive|url=https://web.archive.org/web/20170508013700/https://www.fda.gov/downloads/Food/IngredientsPackagingLabeling/LabelingNutrition/UCM403090.pdf |date=2017-05-08 }} US Food and Drug Administration (June 24, 2014).</ref> A meta-analysis published after the FDA decision reported that psyllium provided before meals improved fasting blood glucose and [[glycated hemoglobin]], but that the larger effect was seen in people diagnosed with and being treated for type 2 diabetes, and only a modest improvement for people classified as pre-diabetic.<ref name=Gibb2015>{{cite journal |vauthors=Gibb RD, McRorie JW, Russell DA, Hasselblad V, D'Alessio DA |title=Psyllium fiber improves glycemic control proportional to loss of glycemic control: a meta-analysis of data in euglycemic subjects, patients at risk of type 2 diabetes mellitus, and patients being treated for type 2 diabetes mellitus |journal=Am. J. Clin. Nutr. |volume=102 |issue=6 |pages=1604–14 |date=December 2015 |pmid=26561625 |doi=10.3945/ajcn.115.106989 |doi-access=free }}</ref>
==== Hypertension ====
A 2019 meta-analysis found that use of supplemental psyllium for 8 weeks or longer reduced blood pressure by 2 mmHg in people with [[hypertension]].<ref name=":1">{{Cite journal |last1=Clark |first1=Cain |last2=Salek |first2=Mina |last3=Aghabagheri |first3=Elahe |last4=Jafarnejad |first4=Sadegh |date=19 February 2019 |title=The effect of psyllium supplementation on blood pressure: a systematic review and meta-analysis of randomized controlled trials |journal=Korean Journal of International Medicine |volume=35 |issue=6 |pages=1385–1399 |doi=10.3904/kjim.2019.049 |pmid=32066221 |pmc=7652639 }}</ref>
===Lead content===
Psyllium supplements have been found to contain [[lead]],<ref name = lead>{{cite web | url = https://www.consumerlab.com/news/best-psyllium-fiber-supplements-2024/02-29-2024/|title = Lead Found In Psyllium Fiber Supplements |date = 29 Feb 2024}}</ref> in some cases exceeding levels requiring a warning label by [[1986 California Proposition 65|Proposition 65]] of the U.S. state of California.<ref name = lead></ref> In 2013, in California, a [[Settlement (litigation)|legal settlement]] required the manufacturer of psyllium supplements to pay US$110,000 and agree to place warning labels on products exceeding acceptable lead levels <ref>{{cite web | url=https://oag.ca.gov/system/files/prop65/settlements/2011-00946S2908.pdf |title=Settlement Agreement and Release|website =State of California - Department of Justice|date = 8 Nov 2013}}</ref>
===Veterinary medicine===
Psyllium fiber dietary supplements are used in veterinary medicine to treat [[sand impaction]] in horses to aid in elimination of sand from the horse's colon.<ref>{{cite journal |last1=Niinistö |first1=K.E. |last2=Ruohoniemi |first2=M.O. |last3=Freccero |first3=F. |last4=Raekallio |first4=M.R. |title=Investigation of the treatment of sand accumulations in the equine large colon with psyllium and magnesium sulphate |journal=The Veterinary Journal |date=August 2018 |volume=238 |pages=22–26 |doi=10.1016/j.tvjl.2018.06.005|pmid=30103912 |doi-access=free |hdl=11585/636256 |hdl-access=free }}</ref>
==Adverse effects==
Fiber generally has few side effects.<ref name=Dah2015/>
* Mild to moderate [[flatulence]] (gas).<ref name=Dah2015>{{cite journal|last1=Dahl|first1=WJ|last2=Stewart|first2=ML|title=Position of the Academy of Nutrition and Dietetics: Health Implications of Dietary Fiber.|journal=Journal of the Academy of Nutrition and Dietetics|date=November 2015|volume=115|issue=11|pages=1861–70|doi=10.1016/j.jand.2015.09.003|pmid=26514720}}</ref><ref name="Rao2021" />
* Mild to moderate [[abdominal distension]] ([[bloating]]) and [[abdominal pain]].<ref name="Rao2021" />
* Choking is a hazard if psyllium is taken without adequate water as it thickens in the throat.<ref name=":0">{{Cite news|url=http://www.webmd.com/drugs/2/drug-13722/metamucil-oral/details|title=Metamucil oral : Uses, Side Effects, Interactions, Pictures, Warnings & Dosing – WebMD|newspaper=WebMD|language=en-US|access-date=2016-11-17|archive-url=https://web.archive.org/web/20161118040831/http://www.webmd.com/drugs/2/drug-13722/metamucil-oral/details|archive-date=2016-11-18|url-status=live}}</ref>
* Psyllium can cause bowel obstructions or [[bezoar]]s, if taken without adequate amounts of water.<ref name="pmid8590522">{{cite journal |vauthors=Stack PE, Thomas E |title=Pharmacobezoar: an evolving new entity |journal=Dig Dis |volume=13 |issue=6 |pages=356–64 |date=1995 |pmid=8590522 |doi=10.1159/000171515 }}</ref><ref name="pmid29085697">{{cite journal |vauthors=Abou Azar S, Wehbe MR, Jamali S, Hallal A |title=Small Bowel Obstruction Secondary to a Metamucil Bezoar: Case Report and Review of the Literature |journal=Case Rep Surg |volume=2017 |pages=2702896 |date=2017 |pmid=29085697 |pmc=5632449 |doi=10.1155/2017/2702896 |doi-access=free }}</ref>
===Allergy===
Psyllium can cause [[allergic reaction]]s, including [[anaphylaxis]].<ref name="Khalili-2003">{{Cite journal  | last1 = Khalili | first1 = B. | last2 = Bardana | first2 = EJ. | last3 = Yunginger | first3 = JW. | title = Psyllium-associated anaphylaxis and death: a case report and review of the literature | journal = Ann Allergy Asthma Immunol | volume = 91 | issue = 6 | pages = 579–84 |date=Dec 2003 | doi = 10.1016/S1081-1206(10)61538-4 | pmid = 14700444 }}</ref> Psyllium may act as a potent inhalant allergen capable of eliciting asthma symptoms.<ref name="pmid11181258">{{cite journal |vauthors=Alemán AM, Quirce S, Bombín C, Sastre J |title=[Asthma related to inhalation of Plantago ovata] |language=es|journal=Med Clin (Barc) |volume=116 |issue=1 |pages=20–2 |year=2001 |pmid=11181258 |doi= 10.1016/S0025-7753(01)71705-8}}</ref> Health care professionals at geriatric care hospitals, who are frequently exposed to psyllium in the [[laxative]]s administered to people, are commonly [[Type I hypersensitivity|IgE sensitized]] to psyllium (13.8%), and 8.6% have clinical allergy to psyllium.<ref name="pmid18564629">{{cite journal |vauthors=Bernedo N, García M, Gastaminza G, Fernández E, Bartolomé B, Algorta J, Muñoz D |title=Allergy to laxative compound (Plantago ovata seed) among health care professionals |journal=J Investig Allergol Clin Immunol |volume=18 |issue=3 |pages=181–9 |year=2008 |pmid=18564629 }}</ref> In order to protect sensitized workers, psyllium has an extremely low [[occupational exposure limit]] of 150&nbsp;ng/m<sup>3</sup>.<ref>{{cite web |title=Metamucil Orange Coarse Milled Original Texture MSDS |url=https://www.pg.com/productsafety/msds/health_care/gastrointestinal/Metamucil_Orange_Coarse_Milled_Original_Texture.pdf |publisher=Procter & Gamble |access-date=July 22, 2019 |archive-url=https://web.archive.org/web/20190722230846/https://www.pg.com/productsafety/msds/health_care/gastrointestinal/Metamucil_Orange_Coarse_Milled_Original_Texture.pdf |archive-date=July 22, 2019 |url-status=live }}</ref>
==Cultivation==
The genus ''Plantago'' contains over 200 species. ''[[Plantago ovata|P.&nbsp;ovata]]'' and ''P.&nbsp;psyllium'' are produced commercially in several European countries, Russia and surrounding countries, and [[India]]. Plantago seed, known commercially as black, French, or Spanish psyllium, is obtained from ''P.&nbsp;psyllium'', also known as ''P.&nbsp;arenaria''. Seed produced from ''P.&nbsp;ovata'' is known in trading circles as white or blonde psyllium, Indian plantago, or isabgol. Isabgol is the common name in India for ''P.&nbsp;ovata''. India dominates the world market in the production and export of psyllium.
''Plantago ovata'' is an annual herb that grows to a height of {{convert|30|-|46|cm|in|abbr=on}}. Leaves are opposite, linear or linear [[lanceolate]] {{convert|1|x|19|cm|in|abbr=on}}. The root system has a well-developed tap root with few fibrous secondary roots. A large number of flowering shoots arise from the base of the plant. Flowers are numerous, small, and white. Plants flower about 60 days after planting. The seeds are enclosed in capsules that open at maturity.
The fields are generally irrigated prior to seeding to achieve ideal soil moisture, to enhance seed soil contact, and to avoid burying the seed too deeply as a result of later irrigations or rainfall. Maximum germination occurs at a seeding depth of 6&nbsp;mm (1/4 in). Emerging seedlings are frost sensitive; therefore, planting should be delayed until conditions are expected to remain frost free. Seed is broadcast at 5.5 to 8.25&nbsp;kg/hectare (5 to 7.5&nbsp;lb/acre) in India. In Arizonan trials, seeding rates of 22 to 27.5&nbsp;kg/ha (20 to 25&nbsp;lb/acre) resulted in stands of 1 plant/25mm (1&nbsp;inch) in 15&nbsp;cm (6&nbsp;inch) rows produced excellent yields. Weed control is normally achieved by one or two hand weedings early in the growing season. Control of weeds by pre-plant irrigation that germinates weed seeds followed by shallow [[tillage]] may be effective on fields with minimal weed pressure. Psyllium is a poor competitor with most weed species.
Plantago wilt (''[[Fusarium oxysporum]]'') and [[downy mildew]] (''Peronospora alta'') are the major diseases of Isabgol. [[White grub]]s and [[aphid]]s are the major insect pests.
The flower spikes turn reddish brown at ripening, the lower leaves dry and the upper leaves yellow. The crop is harvested in the morning after the dew is gone to minimize shattering and field losses. In India, mature plants are cut 15&nbsp;cm above the ground and then bound, left for a few days to dry, thrashed, and [[winnowed]].
Harvested seed must be dried to below 12% moisture to allow for cleaning, milling, and storage. Seed stored for future crops has shown a significant loss in viability after 2 years in storage.
==Commercial history==
===Metamucil===
{{see|Metamucil}}
Introduced in 1934 by [[G.D. Searle & Company]], Metamucil was acquired by [[Procter & Gamble]] in 1985. The name is a combination of the Greek word for change (meta) and the class of fiber that it utilizes (mucilage). In its early years, Metamucil achieved sporadic [[drug store|drug-store]] distribution as a "behind the counter" product – sold in pharmacies but not on the shelf, so that the pharmacist may counsel the purchaser on correct usage. Since 1974, the brand was also marketed to consumers by print and TV advertising and became available in food outlets. Flavored versions were added in 1979.
The brand is sold as powdered [[drink mix]]es, capsules, gummies, and wafers in a variety of flavors. Metamucil contains psyllium seed husks as the active ingredient. It is manufactured in Phoenix, Arizona, by Procter & Gamble.<ref>{{cite news | url=https://www.fox10phoenix.com/news/made-in-arizona-valley-factory-makes-metamucil-for-shipping-around-the-world| title= Made In Arizona: Valley factory makes Metamucil for shipping around the world | publisher= Fox10 | author= Carilla, Christina | date=Jan 25, 2019 | access-date=2020-01-21}}</ref> When first marketed to consumers in 1974, Metamucil was marketed as a laxative. The advertising slogan at that time was "If not nature, then Metamucil". Procter & Gamble sought to make Metamucil a household name by advertising in magazines and on television, using the claim "All fiber is not created equal".<ref>{{cite book |title=Precision Marketing: The New Rules for Attracting, Retaining, and Leveraging Profitable Customers |publisher=John Wiley & Sons |date=2004 |author=Zabin, Jeff |pages=58–59}}</ref>
==References==
{{Reflist}}
==External links==
* [http://plants.usda.gov/java/profile?symbol=PLOV USDA Plants Profile: ''Plantago ovata'' Forsk.]
* [https://web.archive.org/web/20120925194424/http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?28790 USDA Germplasm Resources Information Network: ''Plantago ovata'' Forsk.]
* [https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=504438 ITIS Standard Report: ''Plantago ovata'' Forsk.]
* [http://plants.usda.gov/java/profile?symbol=PLPS USDA Plants Profile: ''Plantago psyllium'' L.]
* [https://web.archive.org/web/20120925194513/http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?316476 USDA Germplasm Resources Information Network: ''Plantago psyllium'' L. (''Plantago arenaria'')]
{{Herbs used as laxatives}}
{{Authority control}}
[[Category:Crops]]
[[Category:Medicinal plants]]
[[Category:Plantago]]
[[Category:Edible thickening agents]]
[[Category:Natural gums]]