{{short description|Species of tree and its edible seeds}} {{distinguish|text=the brazilwood tree}} {{Speciesbox | name = Brazil nut tree | image = Bertholletia excelsa compose.jpg | status = VU | status_system = IUCN2.3 | status_ref = <ref name=IUCN>{{cite iucn |author=((Americas Regional Workshop (Conservation & Sustainable Management of Trees, Costa Rica, November 1996))) |year=1998 |title=''Bertholletia excelsa''|doi=10.2305/IUCN.UK.1998.RLTS.T32986A9741363.en|article-number=e.T32986A9741363|access-date=2 December 2023}}</ref> | genus = Bertholletia | parent_authority = Bonpl. | species = excelsa | authority = Humb. & Bonpl. }} '''Brazil nut''' ('''''Bertholletia excelsa''''') refers to a South American tree of the monotypic genus ''Bertholletia'' in the family Lecythidaceae as well as the tree's commercially-harvested edible seeds.<ref name="mori">{{cite web |author=Mori, Scott A. |title=The Brazil Nut Industry – Past, Present, and Future |url=http://www.nybg.org/bsci/braznut |publisher=The New York Botanical Garden |access-date=July 17, 2012}}</ref> It is one of the largest and longest-lived trees in the Amazon rainforest. The fruit and its nutshell – containing the edible nut – are relatively large and weigh as much as {{cvt|2|kg|lb|1}} in total. As food, Brazil nuts are notable for diverse content of micronutrients, especially a high amount of selenium. The wood of the Brazil nut tree is prized for its quality in carpentry, flooring, and heavy construction.
In 2023, Brazil and Bolivia combined produced 91% of the world total of Brazil nuts.
==Common names==
In Portuguese-speaking countries, like Brazil, they are variously called "{{lang|pt|castanha-do-brasil|italic=yes}}"<ref name=":p0">{{cite web |url=https://ainfo.cnptia.embrapa.br/digital/bitstream/item/47749/1/folder-castanhadobrasil.pdf | title=Nomes comuns: castanha-do-brasil, castanha-do-pará ou castanha-da-amazônia }} - Folder Embrapa</ref><ref name=":p1">COSTA, J. R. (et al.).[http://www.scielo.br/pdf/aa/v39n4/v39n4a13.pdf Uma das espécies nativas mais valiosas da floresta amazônica de terra firme é a castanha-do-brasil ou castanha-da-amazônia (''Bertholletia excelsa'')], - Acta Amazônica vol. 39(4) 2009: 843 - 850</ref> (meaning "chestnut from Brazil" in Portuguese), "{{lang|pt|castanha-do-pará|italic=yes}}" (meaning "chestnut from Pará" in Portuguese), castanha-da-amazônia,<ref>{{cite book |last1=Filho |first1=João Carlos Meireles |title=O livro de ouro da Amazônia: mitos e verdades sobre a região mais cobiçada do planeta |date=2004 |publisher=Ediouro |isbn=978-85-00-01357-7 |url=https://books.google.com/books?id=TvIrAAAAYAAJ&q=%22a%20%C3%BAnica%20conhecida%20fora%22 |access-date=8 July 2023 |language=pt-BR}}</ref> castanha-do-acre,<ref>{{cite web |url=http://www.ambiente.sp.gov.br/wp-content/uploads/cea/wwf_1.pdf | title=Negócios para Amazônia sustentável | access-date=July 8, 2023 | archive-date=October 19, 2016 | archive-url=https://web.archive.org/web/20161019081742/http://www.ambiente.sp.gov.br/wp-content/uploads/cea/wwf_1.pdf }} - Ministério do Meio Ambiente. Rio de Janeiro, 2003. p. 50.</ref> "{{lang|pt|noz amazônica|italic=yes}}" (meaning "Amazonian nut" in Portuguese), noz boliviana, tocari (probably of Carib origin<ref>{{cite journal |last1=Shepard |first1=Glenn H. |last2=Ramirez |first2=Henri |title="Made in Brazil": Human Dispersal of the Brazil Nut (Bertholletia excelsa, Lecythidaceae) in Ancient Amazonia1 |journal=Economic Botany |date=March 2011 |volume=65 |issue=1 |pages=44–65 |doi=10.1007/s12231-011-9151-6|s2cid=43465637 }}</ref>), and tururi (from Tupi ''turu'ri''<ref>Ferreira, A. B. H. (1986). ''Novo Dicionário da Língua Portuguesa'' (2nd edition). Rio de Janeiro: Nova Fronteira. p. 1729</ref>).<ref name=mori/>
In various Spanish-speaking countries of South America, Brazil nuts are called {{lang|es|castañas de Brasil|italic=yes}}, {{lang|es|nuez de Brasil|italic=yes}}, or {{lang|es|castañas de Pará (or Para)|italic=yes}}.<ref name=mori/><ref>{{Cite report|url=http://www.puntofocal.gov.ar/notific_otros_miembros/ury45_t.pdf|title=PROYECTO PARA DECLARACIÓN DE ALÉRGENOS y SUSTANCIAS QUE PRODUCEN REACCIONES ADVERSAS EN LOS RÓTULOS DE LOS ALIMENTOS, CUALQUIERA SEA SU ORIGEN, ENVASADOS EN AUSENCIA DEL CLIENTE, LISTOS PARA SER OFRECIDOS AL CONSUMIDOR (DEC. 117/006 DEL RBN)|trans-title=Project for Declaration of Allergens and Substances that produce adverse reactions in food labels, whatever their origin, packaged in the absence of the client, ready to be offered to the consumer|publisher=Argentine government|date=n.d.|page=3|archive-date=July 23, 2024|access-date=November 1, 2022|archive-url=https://web.archive.org/web/20240723212637/http://www.puntofocal.gov.ar/notific_otros_miembros/ury45_t.pdf|url-status=dead}}</ref>
In North America, as early as 1896, Brazil nuts were sometimes known by the slang term "nigger toes",<ref>{{cite book |last=Lyons |first=A. B. |year=2015 |title=Plant Names, Scientific and Popular |edition=2nd |publisher=Arkose Press |page=71 |isbn=978-1-345-21184-9}}</ref><ref>{{cite journal |last=Young |first=W. J. |year=1911 |title=The Brazil Nut |journal=Botanical Gazette |volume=52 |issue=3 |pages=226–231 |doi=10.1086/330613 |url=https://zenodo.org/record/1431393 |doi-access=free}}</ref><ref>{{cite dictionary |title="Nigger", noun and adjective |dictionary=Oxford English Dictionary |url=https://www.oed.com/viewdictionaryentry/Entry/126934 |access-date=29 November 2019 |date=2019}}</ref> a vulgarity that fell out of use after the racial slur became socially unacceptable.<ref>{{cite magazine |author1=Essig, Laurie |date=12 July 2016 |title=White Like Me, Nice Like Me |magazine=Psychology Today |url=https://www.psychologytoday.com/us/blog/social-studies/201607/white-me-nice-me |access-date=29 November 2019}}</ref><ref>{{cite journal|last=Brunvand|first=J. H. |year=1972 |title=The Study of Contemporary Folklore: Jokes |journal=Fabula |volume=13 |issue=1 |pages=1–19 |doi=10.1515/fabl.1972.13.1.1 |s2cid=162318582 |url=https://www.proquest.com/openview/e3d74c14ec7bc60598cb9d7711acc84f/1?pq-origsite=gscholar&cbl=1818081|url-access=subscription }}</ref>
== Description == [[Image:Brazil Nut - Project Gutenberg eBook 11662.jpg|thumb|Depiction of the Brazil nut in ''Scientific American Supplement'', No. 598, June 18, 1887]]
The Brazil nut is a large tree, reaching {{Convert|50|m|abbr=off}} tall,<ref name="henn">{{cite web|title=The Brazil Nut (''Bertholletia excelsa'') |last=Hennessey |first=Tim |url=http://www.siu.edu/~ebl/leaflets/brazil.htm |date=March 2, 2001 |access-date=July 17, 2012 |archive-url=https://web.archive.org/web/20090111010933/http://www.siu.edu/~ebl/leaflets/brazil.htm|archive-date=January 11, 2009}}</ref> with a trunk {{cvt|1|to|2|m|ft|0}} in diameter, making it among the largest of trees in the Amazon rainforest. It may live for 500 years or more, and can often reach a thousand years of age.<ref>{{cite web |title=Harvesting nuts, improving lives in Brazil| url= http://www.assets.wwf.no/news_facts/newsroom/features/index.cfm?uNewsID=92320|publisher=World Wildlife Fund |author=Taitson, Bruno |date=January 18, 2007 |access-date=July 17, 2012 |archive-date=May 23, 2008 |archive-url= https://web.archive.org/web/20080523200535/http://www.assets.wwf.no/news_facts/newsroom/features/index.cfm?uNewsID=92320}}</ref> The stem is straight and commonly without branches for well over half the tree's height, with a large, emergent crown of long branches above the surrounding canopy of other trees.
The bark is grayish and smooth. The leaves are dry-season deciduous, alternate, simple, entire or crenate, oblong, {{Convert|20-35|cm|frac=2}} long, and {{cvt|10|–|15|cm|0}} broad. The flowers are small, greenish-white, in panicles {{cvt|5|–|10|cm|in|0}} long; each flower has a two-parted, deciduous calyx, six unequal cream-colored petals, and numerous stamens united into a broad, hood-shaped mass.{{citation needed|date=December 2014}}
===Reproduction=== Brazil nut trees produce fruit almost exclusively in pristine forests, as disturbed forests lack the large-bodied bees of the genera ''Bombus'', ''Centris'', ''Epicharis'', ''Eulaema'', and ''Xylocopa'', which are the only ones capable of pollinating the tree's flowers, with different bee genera being the primary pollinators in different areas, and different times of year.<ref name=Nelson1985>{{cite journal | author = Nelson, B. W. | author2 = Absy, M. L. | author3 = Barbosa, E. M. | author4 = Prance, G. T. | date = January 1985 | title = Observations on flower visitors to ''Bertholletia excelsa'' H. B. K. and ''Couratari tenuicarpa'' A. C. Sm. (Lecythidaceae) | journal = Acta Amazonica | volume = 15 | issue = 1 | pages = 225–234 | url = https://www.researchgate.net/publication/315244593 | access-date = 2023-06-06 | doi = 10.1590/1809-43921985155234 |doi-access=free | s2cid = 87265447 }}</ref><ref name=Moritz1984>{{cite book | author = Moritz, A. | year = 1984 | title = Estudos biológicos da floração e da frutificação da castanha-do-Brasil (''Bertholletia excelsa'' HBK) | trans-title = Biological studies of flowering and fruiting of Brazil nuts (''Bertholleira excelsa'' HKB) | language = pt | volume = 29 | url = http://orton.catie.ac.cr/cgi-bin/wxis.exe/?IsisScript=ACERVO.xis&method=post&formato=2&cantidad=1&expresion=mfn=029738 | access-date = 2008-04-08 | archive-date = August 17, 2009 | archive-url = https://web.archive.org/web/20090817104252/http://orton.catie.ac.cr/cgi-bin/wxis.exe/?IsisScript=ACERVO.xis&method=post&formato=2&cantidad=1&expresion=mfn=029738 }}</ref><ref>{{cite journal|title=Pollination Requirements and the Foraging Behavior of Potential Pollinators of Cultivated Brazil Nut (''Bertholletia excelsa'' Bonpl.) Trees in Central Amazon Rainforest |first1=M. C. |last1=Cavalcante |first2=F. F. |last2=Oliveira |first3=M. M. |last3=Maués |first4=B. M. |last4=Freitas |date=October 27, 2017 |journal=Psyche: A Journal of Entomology |volume=2012 |pages=1–9 |doi=10.1155/2012/978019 |doi-access=free}}</ref> Brazil nuts have been harvested from plantations, but production is low and is currently not economically viable.<ref name=mori/><ref name=henn/><ref>{{cite web |title=The Brazil Nut Tree: More than just nuts |url=http://www.bertholletia.org/bertholletia/benefits/body_benefits.html |last=Ortiz |first=Enrique G. |access-date=July 17, 2012 |url-status=live |archive-url= https://web.archive.org/web/20080216221836/http://www.bertholletia.org/bertholletia/benefits/benefits.html |archive-date=February 16, 2008}}</ref>
thumb|A freshly cut Brazil nut fruit
The fruit takes 14 months to mature after pollination of the flowers. The fruit itself is a large capsule {{cvt|10|–|15|cm|0}} in diameter, resembling a coconut endocarp in size and weighing up to {{cvt|2|kg|lboz}}. It has a hard, woody shell {{cvt|8|–|12|mm|frac=8}} thick, which contains eight to 24 wedge-shaped seeds {{cvt|4|–|5|cm|frac=8}} long (the "Brazil nuts") packed like the segments of an orange, but not limited to one whorl of segments. Up to three whorls can be stacked onto each other, with the polar ends of the segments of the middle whorl nestling into the upper and lower whorls (see illustration above).
The capsule contains a small hole at one end, which enables large rodents like the agouti to gnaw it open.<ref name="seeds">{{cite journal |last1=Haugaasen |first1=Joanne M. Tuck |last2=Haugaasen |first2=Torbjørn |last3=Peres |first3=Carlos A. |last4=Gribel |first4=Rogerio |last5=Wegge |first5=Per |title=Seed dispersal of the Brazil nut tree (''Bertholletia excelsa'') by scatter-hoarding rodents in a central Amazonian forest |journal=Journal of Tropical Ecology| volume=26 |issue=3 |date=2010-03-30 |doi=10.1017/s0266467410000027 |pages=251–262 |url=https://www.researchgate.net/publication/230679775 |s2cid=84855812}}</ref> They then eat some of the seeds inside while burying others for later use; some of these are able to germinate into new Brazil nut trees.<ref name=seeds/> Most of the seeds are "planted" by the agoutis in caches during wet season,<ref name=seeds/> and the young saplings may have to wait years, in a state of dormancy, for a tree to fall and sunlight to reach it, when it starts growing again.
== Taxonomy == The Brazil nut family, the Lecythidaceae, is in the order Ericales, as are other well-known plants such as blueberries, cranberries, sapote, gutta-percha, tea, phlox, and persimmons. The tree is the only species in the monotypic genus ''Bertholletia'',<ref name="mori" /> named after French chemist Claude Louis Berthollet.<ref>{{cite book |last=Burkhardt |first=Lotte |title=Eine Enzyklopädie zu eponymischen Pflanzennamen |publisher=Botanic Garden and Botanical Museum, Freie Universität Berlin |year=2022 |isbn=978-3-946292-41-8 |location=Berlin |language=German |trans-title=Encyclopedia of eponymic plant names |doi=10.3372/epolist2022 |s2cid=246307410}}</ref>
==Distribution and habitat== The Brazil nut is native to the Guianas, Venezuela, Brazil, eastern Colombia, eastern Peru, and eastern Bolivia. It occurs as scattered trees in large forests on the banks of the Amazon River, Rio Negro, Tapajós, and the Orinoco. The fruit is heavy and rigid; when the fruits fall, they pose a serious threat to vehicles and potential for traumatic brain injury of people passing under the tree.<ref name="ideta">{{cite journal |vauthors=Ideta MM, Oliveira LM, de Castro GL, Santos MA, Simões EL, Gonçalves DB, de Amorim RL |date=2021 |title=Traumatic brain injury caused by Brazil-nut fruit in the Amazon: A case series |journal=Surgical Neurology International |volume=12 |page=399 |doi=10.25259/SNI_279_2021 |pmc=8422441 |pmid=34513165}}</ref>
==Production== {{Table alignment}}
{| class="wikitable floatright col2right"
|+ Brazil nut production <br />{{small|2023, tonnes}} |- | {{BRA}} || 35,351 |- | {{BOL}} || 33,650 |- | {{PER}} || 6,909 |- | '''World''' || '''75,910''' |- |colspan=2|{{small|Source: FAOSTAT<br> of the United Nations}}<ref name="faostat">{{cite web|url=https://www.fao.org/faostat/en/#data/QCL |title= Production of Brazil nuts (in shell) in 2023; Crops/Regions/World list/Production Quantity (pick lists)|date=2025|publisher=UN Food and Agriculture Organization, Corporate Statistical Database (FAOSTAT)|access-date=27 June 2025}}</ref> |} In 2023, world production of Brazil nuts (in shells) was 75,910 tonnes, most of which derive from wild harvests in tropical forests, especially the Amazon regions of Brazil and Bolivia which together produced 91% of the total (table).
===Environmental effects of harvesting=== Since most of the production for international trade is harvested in the wild,<ref name="evans">{{cite web |last= Evans| first= Kate |title=Harvesting both timber and Brazil nuts in Peru's Amazon forests: Can they coexist? |url=https://forestsnews.cifor.org/16623/harvesting-both-timber-and-brazil-nuts-in-perus-amazon-forests-can-they-coexist?fnl=en |work=Forests News |publisher= Center for International Forestry Research| via= CIFOR.org |access-date=2 May 2019 |date=7 November 2013}}</ref><ref name="kivner">{{cite news |last= Kivner| first= Mark |title=Intensive harvests 'threaten Brazil nut tree future' |url=https://www.bbc.com/news/10105273 |access-date=2 May 2019 |work=BBC News: Science and Environment |date=11 May 2010}}</ref> the business arrangement has been advanced as a model for generating income from a tropical forest without destroying it.<ref name=evans/> The nuts are most often gathered by migrant workers known as ''castañeros'' (in Spanish) or ''castanheiros'' (in Portuguese).<ref name=evans/> Logging is a significant threat to the sustainability of the Brazil nut–harvesting industry.<ref name=evans/><ref name= kivner/>
Analysis of tree ages in areas that are harvested shows that moderate and intense gathering takes so many seeds that not enough are left to replace older trees as they die.<ref name=kivner/> Sites with light gathering activities had many young trees, while sites with intense gathering practices had nearly none.<ref>{{Cite journal | last1 = Silvertown | first1 = J. | title = Sustainability in a nutshell | doi = 10.1016/j.tree.2004.03.022 | journal = Trends in Ecology & Evolution | volume = 19 | issue = 6 | pages = 276–278| year = 2004 | pmid = 16701269}}</ref>
==Toxicity== left|thumb|Brazil nuts after shell removal
Brazil nuts are susceptible to contamination by aflatoxins, produced by fungi, once they fall to the ground.<ref>{{Cite web |date=1 March 2007 |title=Aflatoxins in food |url=https://www.efsa.europa.eu/en/topics/topic/aflatoxins-food |website=European Food Safety Authority |language=en}}</ref> Aflatoxins can cause liver damage, including possible cancer, if consumed.<ref name=eujournal>{{cite journal|title=Commission Decision of 4 July 2003 imposing special conditions on the import of Brazil nuts in shell originating in or consigned from Brazil |url= https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2003:168:0033:0038:EN:PDF|pages=33–38|id=2003/493/EC |journal=Official Journal of the European Union|date=5 July 2003}}</ref> Aflatoxin levels have been found in Brazil nuts during inspections that were far higher than the limits set by the EU.<ref>{{Cite web |date=2 August 2017 |title=Research improves the control of Brazil nut contamination by mycotoxins |url=https://agencia.fapesp.br/research-improves-the-control-of-brazil-nut-contamination-by-mycotoxins/25782/ |website=AGÊNCIA FAPESP |language=en}}</ref> However, mechanical sorting and drying was found to eliminate 98% of aflatoxins; a 2003 EU ban on importation<ref name="eujournal" /> was rescinded after new tolerance levels were set.
Brazil nuts contain naturally high concentrations of selenium. Although selenium is an essential trace element, it is toxic if taken in excess. Exceeding the Tolerable Upper Intake Level of 400 micrograms per day can lead to selenosis. A standard serving measurement (28 g or 1 oz) of Brazil nuts – around 6 to 8 nuts, depending on size – has an average of 544 mcg selenium, though values vary widely. As a result, it's not recommended to eat a full ounce of Brazil nuts daily. Some guidelines suggest limiting intake to no more than two nuts daily, and to be eaten only occasionally, to avoid excessive selenium intake.<ref>{{Cite web |title=Office of Dietary Supplements - Selenium |url=https://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/ |access-date=2026-03-28 |website=ods.od.nih.gov |language=en}}</ref><ref>{{Cite journal |last=Koeder |first=Christian |last2=Keller |first2=Markus |date=2025 |title=Radium levels in Brazil nuts: A review of the literature |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/nbu.12717 |journal=Nutrition Bulletin |language=en |volume=50 |issue=1 |pages=1–11 |doi=10.1111/nbu.12717 |issn=1467-3010 |pmc=11815606 |pmid=39489716}}</ref><ref>{{Cite web |title=Can You Overdose on Nuts? |url=https://www.uhhospitals.org/blog/articles/2023/01/can-you-overdose-on-nuts |access-date=2026-03-28 |website=www.uhhospitals.org |language=en}}</ref>
The nuts may contain traces of radium, a radioactive element, with a kilogram of nuts containing an activity between {{convert|1|and|7|nCi|Bq|lk=on|order=flip|abbr=off|-1}}. This level of radium is small, although higher than in other common foods. According to Oak Ridge Associated Universities, elevated levels of radium in the soil do not directly cause the concentration of radium, but "the very extensive root system of the tree" can concentrate naturally occurring radioactive material, when present in the soil.<ref>{{cite web |date=January 20, 2009 |title=Brazil Nuts |url=https://www.orau.org/health-physics-museum/collection/consumer/food/brazil-nuts.html |url-status=live |archive-url=https://web.archive.org/web/20211006194754/https://www.orau.org/health-physics-museum/collection/consumer/food/brazil-nuts.html |archive-date=October 6, 2021 |access-date=December 17, 2018 |publisher=Oak Ridge Associated Universities }}</ref> Radium can be concentrated in nuts only if it is present in the soil.<ref>{{cite web |last=Adams |first=Rod |date=January 4, 2014 |title=BBC Bang Goes the Theory demonstrates that NOT all Brazil nuts are radioactive |url=https://atomicinsights.com/bbc-bang-goes-theory-changes-mind-brazil-nuts/ |access-date=May 18, 2021 |website=Atomic Insights}}</ref>
Brazil nuts also contain barium, a metal with a chemical behavior quite similar to radium.<ref>{{Cite web |title=Brazil Nuts |url=https://www.orau.org/health-physics-museum/collection/consumer/food/brazil-nuts.html |access-date=2021-10-06 |website=Museum of Radiation and Radioactivity at ORAU |language=en }}</ref> While barium can have toxic side effects when ingested (weakness, vomiting, diarrhea, etc.)<ref>{{Cite web |date=2021-09-03 |title=Biomonitoring Summary |url=https://www.cdc.gov/biomonitoring/Barium_BiomonitoringSummary.html |access-date=2021-10-06 |website=www.cdc.gov |language=en-us}}</ref> the amount present in Brazil nuts is too small to have noticeable health effects.
==Uses== {{nutritionalvalue | name=Brazil nuts, dried, unblanched, shelled | water=3.48 g | kJ=2743 | protein=14.32 g | fat=66.43 g | satfat=15.137 g | monofat=24.548 g | polyfat=20.577 g | carbs=12.27 g | fiber=7.5 g | sugars=2.33 g | starch=0.25 g | calcium_mg=160 | iron_mg=2.43 | magnesium_mg=376 | phosphorus_mg=725 | potassium_mg=659 | sodium_mg=3 | zinc_mg=4.06 | manganese_mg=1.2 | opt1n=Selenium | opt1v=1917 μg | opt2n=Beta-sitosterol | opt2v=64 mg | vitC_mg=0.7 | thiamin_mg=0.617 | riboflavin_mg=0.035 | niacin_mg=0.295 | pantothenic_mg=0.184 | vitB6_mg=0.101 | folate_ug=22 | vitE_mg = 5.73 <!-- amino acids --> | tryptophan=0.141 g | threonine=0.362 g | isoleucine=0.516 g | leucine=1.155 g | lysine=0.492 g | methionine=1.008 g | phenylalanine=0.630 g | tyrosine=0.420 g | valine=0.756 g | arginine=2.148 g | histidine=0.386 g | alanine=0.577 g | aspartic acid=1.346 g | glutamic acid=3.147 g | glycine=0.718 g | proline=0.657 g | serine=0.683 g | source_usda=1 | note=[https://fdc.nal.usda.gov/food-details/170569/nutrients Link to USDA Database entry] }}
=== Nutrition === Brazil nuts are 3% water, 14% protein, 12% carbohydrates, and 66% fats. The fat components are 16% saturated, 24% monounsaturated, and 24% polyunsaturated.<ref name=table>See USDA source in nutrition table.</ref>
In a {{convert|100|g|oz|abbr=off}} reference amount, Brazil nuts supply 659 calories, and are a rich source (20% or more of the Daily Value, DV) of dietary fiber (30% DV), thiamin (54% DV), vitamin E (38% DV), magnesium (106% DV), phosphorus (104% DV), manganese (57% DV), and zinc (43% DV). Calcium, iron, and potassium are present in moderate amounts (10–19% DV).
==== Selenium ==== {{See also|Selenium#Toxicity}}
Brazil nuts are a particularly rich source of selenium, with just {{cvt|28|g|oz|0}} supplying 544 micrograms of selenium or 10 times the DV of 55 micrograms.<ref name=table/><ref name="ods">{{cite web |title=Selenium |url=https://ods.od.nih.gov/factsheets/selenium-HealthProfessional/ |publisher=Office of Dietary Supplements, US National Institutes of Health |access-date=25 July 2022 |date=26 March 2021}}</ref> However, the amount of selenium within batches of nuts may vary considerably.<ref>{{cite journal |last1=Chang |first1=Jacqueline C. |first2=Walter H.| last2=Gutenmann |first3=Charlotte M. |last3=Reid |first4=Donald J.| last4=Lisk |year=1995 |title=Selenium content of Brazil nuts from two geographic locations in Brazil |journal=Chemosphere |volume=30 |issue=4 |pages=801–802 |doi=10.1016/0045-6535(94)00409-N |pmid=7889353 |bibcode=1995Chmsp..30..801C|doi-access=free }}</ref>
The high selenium content is used as a biomarker in studies of selenium intake and deficiency.<ref>{{cite journal |last1=Garcia-Aloy |first1=Mar |last2=Hulshof |first2=Paul J. M. |last3=Estruel-Amades |first3=Sheila |last4=Osté |first4=Maryse C. J. |last5=Lankinen |first5=Maria |last6=Geleijnse |first6=Johanna M. |last7=de Goede |first7=Janette |last8=Ulaszewska |first8=Marynka |last9=Mattivi |first9=Fulvio |last10=Bakker |first10=Stephan J. L. |last11=Schwab |first11=Ursula |last12=Andres-Lacueva |first12=Cristina |title=Biomarkers of food intake for nuts and vegetable oils: an extensive literature search |journal=Genes and Nutrition |volume=14 |issue=1 |page=7 |date=2019-03-19 |doi=10.1186/s12263-019-0628-8 |pmid=30923582 |pmc=6423890 |doi-access=free }}</ref><ref name="Souza">{{cite journal |last1=Souza |first1=R. G. M. |last2=Gomes |first2=A. C. |last3=Naves |first3=M. M. V. |last4=Mota |first4=J. F. |title=Nuts and legume seeds for cardiovascular risk reduction: scientific evidence and mechanisms of action |journal=Nutrition Reviews |volume=73 |issue=6 |date=2015-04-16 |doi=10.1093/nutrit/nuu008 |pages=335–347| pmid=26011909| url=https://academic.oup.com/nutritionreviews/article/73/6/335/1845023|doi-access=free }}</ref> Consumption of just one Brazil nut per day over 8 weeks was sufficient to restore selenium blood levels and increase HDL cholesterol in obese women.<ref name=Souza/>
===Oil=== thumb|Brazil nut oil
Brazil nut oil contains 48% unsaturated fatty acids composed mainly of oleic and linoleic acids, the phytosterol, beta-sitosterol,<ref>{{cite journal|journal=International Journal for Vitamin and Nutrition Research |year=2013|volume=83|issue=5|pages=263–270|doi=10.1024/0300-9831/a000168|title=Phytosterol content and fatty acid pattern of ten different nut types|pmid=25305221|last1=Kornsteiner-Krenn|first1=Margit|last2=Wagner|first2=Karl-Heinz|last3=Elmadfa|first3=Ibrahim}}</ref> and fat-soluble vitamin E.<ref>{{cite journal|journal=International Journal of Food Sciences and Nutrition |year=2006 |volume=57|issue=3–4|pages=219–228|title=Fatty acid profile, tocopherol, squalene and phytosterol content of brazil, pecan, pine, pistachio and cashew nuts|pmid=17127473|doi=10.1080/09637480600768077|last1=Ryan |first1=E. |last2=Galvin |first2=K. |last3=O'Connor |first3=T. P. |last4=Maguire |first4=A. R. |last5=O'Brien |first5=N. M. |s2cid=22030871 }}</ref>
The following table presents the composition of fatty acids in Brazil nut oil:<ref name=table/>
{| class="wikitable" |- | Palmitic acid || 10% |- | Palmitoleic acid || 0.2% |- | Stearic acid || 6% |- | Oleic acid || 24% |- | Linoleic acid || 24% |- | Alpha-linolenic acid || 0.04% |- | Saturated fats || 16% |- | Unsaturated fats || 48% |}
===Wood=== The lumber from Brazil nut trees (not to be confused with Brazilwood) is of excellent quality, having diverse uses from flooring to heavy construction.<ref name=pfaf>{{cite web |title=''Bertholletia excelsa'' - Bonpl. |url=https://pfaf.org/User/Plant.aspx?LatinName=Bertholletia+excelsa |access-date=28 January 2023 |publisher=Plants for a Future}}</ref> Logging the trees is prohibited by law in all three producing countries (Brazil, Bolivia, and Peru). Illegal extraction of timber and land clearances present continuing threats.<ref>{{cite news |title=Greenpeace Activists Trapped by Loggers in Amazon |url=http://www.greenpeace.org/international/en/news/features/activists-trapped-by-loggers071018/ |publisher=Greenpeace |date=October 18, 2007|access-date=July 17, 2012 |archive-date=2010-12-22 |archive-url=https://web.archive.org/web/20101222112635/http://www.greenpeace.org/international/en/news/features/activists-trapped-by-loggers071018/}}</ref> In Brazil, cutting down a Brazil nut tree requires previous authorization from the Brazilian Institute of Environment and Renewable Natural Resources.<ref>{{cite web |last=Moncrieff |first=Virginia M. |date=2015-09-21 |title=A little logging may go a long way |url=https://forestsnews.cifor.org/33554/brazil-nut-special-for-brazil-nuts-a-little-logging-may-go-a-long-way |access-date=2020-07-08 |work=Forest News |publisher=Center for International Forestry Research |via=CIFOR.org}}</ref><ref>{{cite web |last1=de Oliveira Wadt |first1=Lucia Helena |last2=de Souza |first2=Joana Maria Leite |title=Árvore do Conhecimento – Castanha-do-Brasil |trans-title=Tree of Knowledge – Brazil nut |url=https://www.agencia.cnptia.embrapa.br/gestor/castanha-do-brasil/arvore/CONT000g1kpc3vg02wx5ok00gmbp4skbjdei.html |website=Brazilian Agricultural Research Corporation |language=pt-br |access-date=July 8, 2020 |archive-date=July 8, 2020 |archive-url=https://web.archive.org/web/20200708174055/https://www.agencia.cnptia.embrapa.br/gestor/castanha-do-brasil/arvore/CONT000g1kpc3vg02wx5ok00gmbp4skbjdei.html |url-status=dead }}</ref>
===Other uses=== Brazil nut oil is used as a lubricant in clocks<ref>{{Cite book|url=https://books.google.com/books?id=32rWbxUtjeMC&pg=PA131 |title=Edible Medicinal And Non Medicinal Plants: Volume 3, Fruits |last=Lim |first=T. K. |year=2012 |publisher=Springer Science & Business Media |isbn=978-94-007-2534-8}}</ref> and in the manufacturing of paint and cosmetics, such as soap and perfume.<ref name=pfaf/> Because of its hardness, the Brazil nutshell is often pulverized and used as an abrasive to polish materials, such as metals and ceramics, in the same way as jeweler's rouge, while charcoal from the shells can be used to purify water.<ref name=pfaf/>
==See also== * Brazil nut cake * List of culinary nuts * Official list of endangered flora of Brazil * Granular convection, also known as the "Brazil nut effect" {{clear}}
==References== {{Reflist|30em}}
== External links == {{Commons}} {{Wikispecies|Bertholletia excelsa}} {{EB1911 poster|Brazil Nuts}}{{Nuts}} {{Non-timber forest products}} {{Taxonbar|from=Q81671}}
Category:Lecythidaceae Category:Trees of the Amazon rainforest Category:Edible nuts and seeds Category:Fruit trees Category:Trees of Brazil Category:Trees of Bolivia Category:Trees of Colombia Category:Trees of Guyana Category:Trees of Peru Category:Trees of Venezuela Category:Tropical agriculture Category:Crops originating from South America Category:Crops originating from Brazil Category:Crops originating from Bolivia Category:Crops originating from Peru Category:Crops originating from Colombia Category:Flora of the Amazon Category:Vulnerable flora of South America Category:Taxa named by Aimé Bonpland Category:Taxa named by Alexander von Humboldt