📊 Full nutrition facts — per 100g
| Nutrient | Amount | % Daily value | Level |
|---|---|---|---|
| Calories | 659 kcal | 33% | |
| Total fat | 67.1g | — | |
| Saturated fat | 15.1g | — | |
| Carbohydrates | 3.5g | 1% | |
| Dietary fibre | 7.5g | 27% | |
| Protein | 14.3g | 29% | |
| GI | ~15 — Near zero | — | |
| Selenium | 1917µg | 3485% | |
| Magnesium | 376mg | 94% | |
| Thiamine B1 | 0.62mg | 41% | |
| Copper | 1.74mg | 87% | |
| Zinc | 4.06mg | 34% |
Based on Australian NRV. Source: FSANZ and USDA Food Composition Databases.
📈 Glycaemic index (GI)
💊 Key vitamins & minerals
✅ Health benefits
Brazil nuts are the most concentrated dietary source of selenium by a vast margin — a single nut provides approximately 68–90µg of selenium, meeting or exceeding the adult daily requirement (60–70µg). Selenium is essential for thyroid hormone activation (converting inactive T4 to active T3), synthesis of glutathione peroxidase (the body's primary antioxidant enzyme), immune cell function and DNA repair. Selenium deficiency is associated with thyroid dysfunction, increased cancer risk and impaired immunity. Areas with selenium-poor soils — including much of Australia, Europe and New Zealand — have populations at risk of mild selenium insufficiency.
A 2019 randomised trial in the American Journal of Clinical Nutrition found that consuming one Brazil nut daily for 6 months significantly improved cognitive performance (verbal fluency, constructional ability and memory) in older adults compared to placebo. The mechanism involves selenium's role in selenoprotein P (the primary brain selenoprotein), glutathione peroxidase (protecting neurons from oxidative damage) and thyroid hormone metabolism (critical for neurological function). Low selenium status is associated with cognitive decline and depression in population studies.
Brazil nuts provide predominantly unsaturated fats (oleic acid and linoleic acid), ellagic acid (a potent polyphenol antioxidant) and substantial magnesium — all cardiovascular-protective. A small randomised trial found that eating a single serving of Brazil nuts significantly increased HDL cholesterol and reduced LDL cholesterol within 9 hours. Selenium's role in reducing LDL oxidation and reducing vascular inflammation provides additional cardiovascular protection. The magnesium content supports arterial relaxation and blood pressure regulation.
The thyroid gland has the highest concentration of selenium of any organ in the body — selenium is indispensable for the enzymes that convert thyroxine (T4) to the active thyroid hormone triiodothyronine (T3). In people with autoimmune thyroid disease (Hashimoto's thyroiditis), selenium supplementation has been shown in multiple clinical trials to significantly reduce thyroid peroxidase antibodies — the autoimmune markers that drive thyroid destruction. Brazil nuts provide a practical whole-food selenium source for thyroid health support.
⚠️ Who should limit or avoid
Brazil nuts contain approximately 68–90µg of selenium per nut — and the upper tolerable limit for selenium is 400µg per day for adults. Eating 5 or more Brazil nuts daily could exceed the tolerable upper intake level. Chronic excess selenium intake (selenosis) causes: hair loss (the earliest symptom), brittle nails, garlic breath, nerve damage, fatigue, nausea and in severe cases cirrhosis. A serving of 1–3 Brazil nuts (30g) daily is the evidence-based recommendation. Do not take selenium supplements while eating Brazil nuts regularly without professional guidance.
Brazil nuts are tree nuts and a common allergen. People with tree nut allergy — particularly those with cross-reactive allergies to other tree nuts — may react to Brazil nuts. Brazil nut allergy can cause anaphylaxis. Note that Brazil nuts often cross-react with macadamia, cashew and other tree nuts. Always check labels for Brazil nut presence if you have any tree nut allergy.
Brazil nuts are slightly radioactive — their roots grow so deep in the Amazon rainforest that they access naturally occurring radium-226 deposits in deep soil layers, and the radium accumulates in the nuts. The radiation dose from eating 2–3 Brazil nuts per day is minimal and far below any health concern — but it makes Brazil nuts technically the most radioactive commonly eaten food. This is a fascinating fact rather than a practical health concern at normal consumption amounts.
🛒 How to source & use brazil nuts
In-shell Brazil nuts last significantly longer than shelled — the hard shell protects the oil-rich kernel from oxidation and rancidity. Shelled Brazil nuts oxidise quickly due to their high fat content. When buying shelled Brazil nuts, choose vacuum-sealed packets or air-tight containers. Smell shelled Brazil nuts before purchase or at home — fresh nuts smell creamy and mild; rancid nuts smell sharp, bitter or like paint. Rancid Brazil nuts have reduced nutritional quality and unpleasant flavour.
This is the most important advice for Brazil nuts: the appropriate portion is 1–3 nuts (8–25g), not the generous handful you might take with other nuts. One nut per day provides 100% of daily selenium. Three nuts provide approximately 200µg of selenium — well within safe range but already a meaningful dose. A 30g handful (6–8 nuts) provides 400–600µg of selenium — approaching or exceeding the tolerable upper limit if eaten daily. Pre-portion Brazil nuts separately from other nuts to avoid mindless overconsumption.
Brazil nuts have a rich, creamy flavour and buttery texture. Chop and add to granola, muesli or trail mix (in small quantities). Grate over salads like Parmesan — the texture and flavour work beautifully. Brazil nut milk: blend 1/4 cup soaked Brazil nuts with 2 cups water for a creamy, rich plant milk. Blitz into smooth Brazil nut butter (high in selenium — be mindful of portion). Add a single Brazil nut to smoothies as a selenium supplement. Chocolate-covered Brazil nuts: the classic confection works because the creamy nut contrasts the dark chocolate beautifully.
🧊 Storage tips & shelf life
Shelled Brazil nuts oxidise faster than most nuts due to high polyunsaturated fat content. Store in an airtight container away from light and heat. In Australian summer conditions, the pantry may be too warm — transfer to the fridge. Always smell before eating — rancidity is obvious and the nutritional value of rancid nuts is reduced. In-shell Brazil nuts keep much longer but require a nutcracker.
Refrigerating shelled Brazil nuts significantly extends freshness. The cold temperature slows oil oxidation. Store in a sealed bag or airtight container — Brazil nuts readily absorb strong odours from other fridge contents (onion, aged cheese). A vacuum-sealed bag is ideal. For daily use, take out 1–3 nuts at a time rather than leaving the bag open.
Brazil nuts freeze excellently with no quality loss. The selenium and other minerals are fully preserved. Frozen Brazil nuts can be eaten directly from frozen (they are pleasant cold) or thawed at room temperature for 10 minutes. Ideal for buying in bulk when prices are low and portioning out gradually. The freezer is the best long-term storage option for shelled Brazil nuts in Australian conditions.
📖 About brazil nuts — complete guide
The Brazil nut tree (Bertholletia excelsa) is one of the most remarkable trees in the Amazon rainforest — it grows to 50 metres tall, lives for 500–1,000 years, and can only be pollinated by female Eulaema orchid bees, which are themselves dependent on specific orchid species. The nuts are enclosed in a thick, woody pod (botanically a capsule) the size and weight of a cannonball (0.5–2.5kg) — the pods fall from 30–50 metres directly to the forest floor, creating a significant ballistic hazard during nut collection season. Each pod contains 8–24 Brazil nuts arranged like orange segments. Commercial Brazil nut harvesting is almost entirely from wild trees — the Eulaema bee cannot survive in disturbed forest, and plantations have largely failed to produce good yields because the bees do not establish in monoculture settings. This ecological dependency means Brazil nut production is an important economic driver for Amazon rainforest conservation — harvesters (castanheiros) have financial incentive to keep the forest intact.
The selenium content of Brazil nuts is extraordinary and has been the subject of intense nutritional research since the 1980s. The selenium concentration in individual nuts varies widely depending on the soil selenium content of the specific forest location — ranging from 8µg to over 300µg per nut, with an average of approximately 68–90µg. This variability means that published selenium values per nut are averages rather than reliable individual measurements. Despite this variability, even the lowest-selenium Brazil nuts typically provide meaningful selenium contribution, and the highest-selenium nuts from selenium-rich soil areas can easily provide 3–4× the daily requirement in a single nut. The practical implication: eating 1–3 Brazil nuts daily is a reliable and safe selenium strategy; eating 6–10 daily is a potential toxicity risk that depends on the specific batch. The selenium in Brazil nuts is primarily in the organic form selenomethionine, which is more bioavailable than inorganic selenium in supplements.