Brazil Nuts

Species: Bertholletia excelsa
Commercial forms: shelled whole kernels, pieces, roasted/salted, Brazil nut oil, flours/pastes (incl. partially defatted)

Definition
Large, oil-rich tree nuts with a buttery, rich flavor, renowned for their very high selenium content. Used as premium snacks, in bakery/confectionery, and for extraction of edible oil.

Common name: Brazil nuts (Amazon nuts)

Parent plant: Bertholletia excelsa Bonpl.

Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Order: Ericales
Family: Lecythidaceae
Genus: Bertholletia
Species: Bertholletia excelsa Bonpl.

Cultivation and growth conditions

Climate:
The Brazil nut tree is a strictly Amazonian species that requires:

• warm temperatures (25–32 °C),

• very high humidity,

• high and well-distributed rainfall,

• no frost (damage already below 8–10 °C).

It grows in undisturbed primary rainforests with high biodiversity and depends heavily on the natural ecosystem to fruit properly.

Sun exposure:
It prefers full sun once adult, although young plants may initially grow under partial canopy cover.
Mature trees develop huge crowns and need abundant light to support photosynthesis and nut production.

Soil:
Brazil nut trees grow in soils that are:

• deep,

• well drained,

• typically acidic (pH 4.5–6.5),

• rich in organic matter,

• characteristic of non-waterlogged Amazonian forest soils.

They are sensitive to compacted or heavy soils, which restrict root development and promote root rot.

Irrigation:
In the wild, irrigation is not needed because the species is native to areas with more than 2,000 mm annual rainfall.
In experimental plantations:

• consistent watering is required during dry periods,

• waterlogging must always be avoided.

Temperature:

• Germination: 20–28 °C

• Optimal growth: 25–32 °C

• Damage below 10 °C

• Very high relative humidity (70–95%) favors growth and fruiting.

Fertilization:
In natural forest conditions, the tree relies on the high organic matter content and complex nutrient cycling of the ecosystem.
In managed cultivation it responds positively to:

• phosphorus for root development,

• potassium for flowering and fruiting,

• organic fertilization to improve soil structure and biological activity.

Crop care:

• Young plants benefit from protection against weeds and mechanical damage.

• Pruning is minimal, as the tree naturally forms a tall, straight trunk and a large crown.

• In plantations, plant protection against fungi and insects may be necessary.

• The species strongly depends on natural pollinators (especially euglossine bees) and on forest fauna for seed dispersal.

Because of this ecological dependence, intensive cultivation outside the native rainforest is extremely difficult.

Harvest:
The fruits (often called “cocos”) are large, woody, spherical capsules that mature 14–18 months after flowering and fall naturally to the ground.
Each fruit contains 10–25 seeds (the Brazil nuts), each enclosed in a very hard shell.
Harvest consists of collecting the fallen fruits, opening them (usually by hand or with tools), removing the nuts, then drying and grading them.

Propagation:
Brazil nut trees are propagated by seed, but germination is slow.

• Seeds require warm, moist, well-aerated substrates.

• Early growth is very slow.

• Trees typically start fruiting only after 12–20 years.

Vegetative propagation is difficult and rarely used.

Caloric value
~650–700 kcal per 100 g (typical ≈ 656–680 kcal/100 g, varying with moisture and roasting).

Average composition (per 100 g, dry/roasted kernels)

• Fat: ~65–68 g

• Protein: ~14–16 g

• Carbohydrate: ~10–12 g (of which fiber ~7–8 g, sugars ~2–3 g)

• Water: ~2–4 g

• Micronutrients: selenium extremely high (hundreds of µg/100 g; 1–2 nuts can meet or exceed daily needs), plus Mg, P, Cu, Mn, Zn; vitamins B1 (thiamin) notable, some B6 and vitamin E

Fatty-acid profile (indicative, % of total fat)

• MUFA (MonoUnsaturated Fatty Acids—generally heart-friendly): oleic (C18:1) ~35–45%

• PUFA (PolyUnsaturated Fatty Acids—beneficial but balance with Ω-3): linoleic (C18:2, Ω-6) ~30–38%; ALA (α-linolenic, Ω-3) ≤0.5%

• SFA (Saturated Fatty Acids—best in moderation): palmitic (C16:0) ~12–16%, stearic (C18:0) ~8–12%

• Unsaponifiables: phytosterols, tocopherols, trace squalene

Sensory & technological properties

• Texture: crisp when raw; more friable–buttery after roasting.

• Flavor: milky–nutty; roasting (120–160 °C) enhances Maillard notes.

• Oil: straw-colored, mild; good stability due to MUFA and tocopherols.

Food applications

• Snacks: roasted/salted or honey-/chocolate-coated.

• Bakery/confectionery: pralines, brittles, cookies, cakes; defatted flour for gluten-free systems (needs binders).

• Culinary: chopped as toppings; Brazil nut butter; oil for dressings and moderate-heat cooking.

Nutrition & health (key points)

• Selenium: 1–2 nuts can reach or exceed RDA—avoid excess to prevent selenosis (nausea, brittle nails/hair, garlic-like breath; severe cases: neuropathy).

• Lipids: mix of MUFA (favorable) and PUFA Ω-6 (balance with Ω-3 sources). SFA present at moderate levels.

• Fiber and minerals support satiety and metabolic functions.

• Suggested portion: ~15–30 g (≈2–5 nuts), accounting for total selenium in the diet.

Allergens & safety

• Tree nut allergen → risk of IgE-mediated reactions; strict labeling and cross-contact controls.

• Mycotoxins: tropical supply chains require control for aflatoxins—ensure proper drying/storage.

• Natural radioactivity: trees can accumulate soil radioisotopes; typical dietary levels are low and not concerning at normal portions.

• Pets: as with other nuts, not recommended for pets.

Quality & specifications (typical themes)

• Kernel moisture ≤3–4% for crunch and shelf life.

• Low peroxide/anisidine (no rancid off-notes).

• Graded by size and defects (breakage, discoloration, insect damage).

• Residues within legal limits; aflatoxins compliant.

Storage & shelf life

• Store cool, dry, dark, in airtight packaging (nuts absorb odors).

• 6–12 months at controlled ambient; longer if refrigerated/frozen.

• Prefer oxygen-barrier packs (vacuum/inert gas) and moderate temperatures to limit oxidation.

Troubleshooting

• Early rancidity: lower storage temp, use barrier packaging, rotate stock.

• Loss of crunch: light re-dry/re-roast; sugar/salt coatings help.

• Over-friable gluten-free bakes: add binders (xanthan/psyllium/eggs) and balance with starches.

Sustainability

• Native to the Amazon (wild harvest or agroforestry). Favor supply chains with traceability, protection of biodiversity/local communities, and robust post-harvest practices.

Conclusion
Brazil nuts offer a luxurious flavor and a MUFA/PUFA-oriented lipid profile, plus a uniquely high selenium content. Moderate portions and controlled sourcing let you leverage their culinary and nutritional value while maintaining safety and quality.

References__________________________________________________________________________

Godos J, Giampieri F, Micek A, Battino M, Forbes-Hernández TY, Quiles JL, Paladino N, Falzone L, Grosso G. Effect of Brazil Nuts on Selenium Status, Blood Lipids, and Biomarkers of Oxidative Stress and Inflammation: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. Antioxidants (Basel). 2022 Feb 16;11(2):403. doi: 10.3390/antiox11020403. 

Abstract. Tree nuts, including Brazil nuts, have been hypothesized to impact cardiovascular health through the modulation of oxidative stress and inflammation. Nonetheless, a quantitative analysis of these effects has not been performed. Therefore, the aim of this study was to systematically revise and quantify the effect of Brazil nut intervention on selenium status, blood lipids, and biomarkers of oxidative stress and inflammation using a meta-analytical approach. To meet the goals of this study, a systematic search of PubMed, EMBASE, and Web of Science databases of published randomised clinical trials reporting on dietary interventions with Brazil nuts and their effects on selenium status, blood lipids, and markers of oxidative stress and inflammation was performed. Eight articles were included for systematic review and meta-analysis. Based on the conducted analysis, a significant positive effect of Brazil nuts on selenium blood concentration (SMD = 6.93, 95% CI: 3.99; 9.87) was found. Additionally, a positive effect of Brazil nut intervention on glutathione peroxidase activity (SMD = 0.53, 95% CI: 0.07; 0.99) was observed. However, no significant results were found when considering blood lipid levels, including results for total cholesterol (SMD = -0.22, 95% CI: -0.57; 0.14), HDL cholesterol (SMD = -0.04, 95% CI: -0.28; 0.19) and LDL cholesterol (SMD = -0.15; 95% CI: -0.43; 0.13). In conclusion, the findings from this study suggest that Brazil nut consumption improves selenium status and exerts antioxidant effects, which could be considered a potential pathway for the prevention of metabolic disorders related to altered blood lipid profiles. However, further studies are needed to elucidate the effect of Brazil nuts toward blood lipid profile, also preferably controlling for other biomarkers.

Bonifácio DB, Caldas APS, Costa MAC, Rocha DMUP, Hermsdorff HHM, Bressan J. Acute effect of a beverage containing Brazil and cashew nuts on oxidative stress, lipemia, and blood pressure of women with cardiometabolic risk (Brazilian Nuts Study): a randomized clinical trial. Appl Physiol Nutr Metab. 2023 Oct 1;48(10):789-798. doi: 10.1139/apnm-2023-0049. 

Abstract. Nuts are important sources of antioxidants that combat oxidative stress and improve lipid profile as well as vascular function. However, the intake of typical Brazilian nuts and its acute effect on cardiovascular health needs to be better understood. Thus, the present study aimed to evaluate the acute effect of a beverage containing cashew (Anacardium occidentale L.) and Brazil nuts (Bertholletia excelsa H.B.K.) on postprandial oxidative stress, lipemia, and blood pressure of adult women aged 20 to 55 years with cardiometabolic risk. This was an acute, randomized, parallel arm, controlled clinical trial. The participants received either a beverage containing nuts (30 g Brazil nuts + 15 g cashew nuts) or a beverage without nuts with similar macronutrient composition. Oxidative stress markers and lipid profiles were evaluated at fasting and 4 h after beverage consumption. Blood pressure was measured during fasting and after beverage intake (1, 2, 3, and 4 h). In the postprandial state, there was a greater reduction in malondialdehyde levels in the intervention group compared to the control group (-12.3 ± 0.59 vs. -10.7 ± 0.43 µmol/mL; p < 0.05), which was positively correlated with the concentrations of TG (r = 0.399; p < 0.05), VLDL (r = 0.399; p < 0.05), TG/HDL (r = 0.380; p < 0.05), and blood pressure (iAUC SBP r = 0.391; p < 0.05, iAUC DBP r = 0.409; p < 0.05). The remaining oxidative stress markers showed similar postprandial changes between groups. In women with cardiometabolic risk, a beverage containing Brazilian nuts promoted a significant acute reduction on postprandial malondialdehyde levels. The study was registered in the Brazilian Clinical Trials Registry-ReBEC (protocol: RBR-3ntxrm).

Caldas APS, Rocha DMUP, Dionísio AP, Hermsdorff HHM, Bressan J. Brazil and cashew nuts intake improve body composition and endothelial health in women at cardiometabolic risk (Brazilian Nuts Study): a randomized controlled trial. Br J Nutr. 2022 Feb 23:1-38. doi: 10.1017/S000711452100475X.

Abstract. Several mechanisms have been proposed for the beneficial effect of nuts on health. However, Brazil and cashew nuts remain the least studied. We aim to evaluate the effect of these nuts within an energy-restricted diet on body weight, body composition, cardiometabolic markers, and endothelial function in cardiometabolic risk women. Brazilian nuts study is a randomized controlled parallel 8-week dietary intervention trial. Forty women were randomly allocated to 1) Control group: Energy-restricted diet without nuts, n= 19 or, 2) Brazil and cashew nuts group (BN-Group): Energy-restricted diet containing daily 45 g of nuts (15 g of Brazil nuts + 30g of cashew nuts), n= 21. At the beginning and final intervention, anthropometry, body composition, and blood pressure were measured. Fasting blood sampling was obtained to evaluate lipid profile, glucose homeostasis, and endothelial function markers. After 8-week, plasma selenium concentration increased in BN-group (∆ = + 31.5 ± 7.8 μg/L; p= 0.001). Brazil and cashew nuts intake reduced total body fat (-1.3 ± 0.4 %) parallel to improvement of lean mass percentage in BN-group compared to the control. Besides, the soluble adhesion molecule VCAM-1 decreased (24.03 ± 15.7 pg/mL vs. -22.2 ± 10.3 pg/mL; p= 0.019) after Brazil and cashew nuts intake compared to the control. However, lipid and glucose profile markers, apolipoproteins, and blood pressure remained unchanged after the intervention. Thus, the addition of Brazil and cashew nuts to an energy-restricted diet can be a healthy strategy to improve body composition, selenium status, and endothelial inflammation in cardiometabolic risk women.

Thomson CD, Chisholm A, McLachlan SK, Campbell JM. Brazil nuts: an effective way to improve selenium status. Am J Clin Nutr. 2008 Feb;87(2):379-84. doi: 10.1093/ajcn/87.2.379. 

Abstract. Background: Brazil nuts provide a rich natural source of selenium, yet no studies have investigated the bioavailability of selenium in humans. Objective: We investigated the efficacy of Brazil nuts in increasing selenium status in comparison with selenomethionine. Design: A randomized controlled trial was conducted with 59 New Zealand adults. Participants consumed 2 Brazil nuts thought to provide approximately 100 mug Se, 100 mug Se as selenomethionine, or placebo daily for 12 wk. Actual intake from nuts averaged 53 mug Se/d (possible range: 20-84 mug Se). Plasma selenium and plasma and whole blood glutathione peroxidase (GPx) activities were measured at baseline and at 2, 4, 8, and 12 wk, and effects of treatments were compared. Results: Plasma selenium increased by 64.2%, 61.0%, and 7.6%; plasma GPx by 8.3%, 3.4%, and -1.2%; and whole blood GPx by 13.2%, 5.3%, and 1.9% in the Brazil nut, selenomethionine, and placebo groups, respectively. Change over time at 12 wk in plasma selenium (P < 0.0001 for both groups) and plasma GPx activity in the Brazil nut (P < 0.001) and selenomethionine (P = 0.014) groups differed significantly from the placebo group but not from each other. The change in whole blood GPx activity was greater in the Brazil nut group than in the placebo (P = 0.002) and selenomethionine (P = 0.032) groups. Conclusion: Consumption of 2 Brazil nuts daily is as effective for increasing selenium status and enhancing GPx activity as 100 mug Se as selenomethionine. Inclusion of this high-selenium food in the diet could avoid the need for fortification or supplements to improve the selenium status of New Zealanders.

Rajaram S, Damasceno NRT, Braga RAM, Martinez R, Kris-Etherton P, Sala-Vila A. Effect of Nuts on Markers of Inflammation and Oxidative Stress: A Narrative Review. Nutrients. 2023 Feb 22;15(5):1099. doi: 10.3390/nu15051099.

Abstract. Oxidative stress and inflammation are mediators in the pathophysiology of several non-communicable diseases (NCDs). Tree nuts and peanuts lower risk factors of cardiometabolic disease, including blood lipids, blood pressure and insulin resistance, among others. Given their strong antioxidant/anti-inflammatory potential, it is plausible that nuts may also exert a favorable effect on inflammation and oxidative stress. Evidence from systematic reviews and meta-analyses of cohort studies and randomized controlled trials (RCTs) suggest a modest protective effect of total nuts; however, the evidence is inconsistent for specific nut types. In this narrative review, the state of evidence to date is summarized for the effect of nut intake on biomarkers of inflammation and oxidative stress, and an attempt is made to define the gaps in research while providing a framework for future research. Overall, it appears that some nuts, such as almonds and walnuts, may favorably modify inflammation, and others, such as Brazil nuts, may favorably influence oxidative stress. There is a pressing need for large RCTs with an adequate sample size that consider different nut types, and the dose and duration of nut intervention, while evaluating a robust set of biomarkers for inflammation and oxidative stress. Building a stronger evidence base is important, especially since oxidative stress and inflammation are mediators of many NCDs and can benefit both personalized and public health nutrition.