Whole Brazil Nuts | whatsinit

About

What it is and where it shows up.

Whole Brazil nuts (Bertholletia excelsa) are large, oil-rich seeds from an Amazonian tree, consumed as a snack and used in cooking and confectionery. They are exceptionally rich in selenium, healthy fats, protein, and minerals, and are frequently recommended as a natural selenium supplement.

Safety summary

The regulatory and scientific consensus.

Brazil nuts contain extraordinarily high and variable levels of selenium (68–91 mcg per nut), and regular consumption of more than one or two nuts per day can exceed the EFSA tolerable upper intake level of 255 mcg/day, risking selenosis. They are also susceptible to aflatoxin contamination — a genotoxic, carcinogenic mycotoxin — and contain elevated levels of naturally occurring radium and barium, though the health significance of the latter at typical intake is debated. For healthy adults consuming them in moderation (1–2 nuts/day), Brazil nuts are considered safe and nutritious.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
EFSA (European Food Safety Authority) (European Union)	Restricted	In 2023, EFSA set a daily upper limit for selenium of 255 µg for all adults, with lower amounts (70–230 µg) for children and teens depending on age. Consuming more than 1–2 Brazil nuts per day may exceed this limit.source
FDA (Food and Drug Administration) (United States)	Restricted	NIH/FNB tolerable upper intake level (UL) for selenium is 400 µg/day for adults. Brazil nuts contain 68–91 mcg of selenium per nut and could cause selenium toxicity if consumed regularly in large amounts.source

Who should approach with care

Whose guidance would steer them away.

Children — Children have lower selenium tolerable upper intake levels (70–230 µg/day per EFSA) and studies show that even modest Brazil nut servings in children with already-adequate dietary selenium can push intake to potentially toxic levels.

Pregnancy — Selenium requirements increase during pregnancy but excessive intake via Brazil nuts can approach or exceed the tolerable upper level; moderation (1–2 nuts/day) is advised and high-dose consumption should be avoided.

Kidney Disease — Impaired renal function reduces selenium excretion, raising the risk of selenium accumulation and toxicity from Brazil nut consumption; elevated barium content may also pose additional renal stress.

Liver Disease — Aflatoxin contamination in Brazil nuts is associated with liver cancer risk, and individuals with pre-existing liver disease (especially hepatitis B carriers) face substantially higher risk from aflatoxin exposure.

Nut Allergy — Brazil nuts are a tree nut and a recognised major allergen; individuals with tree nut allergies must avoid them entirely as reactions can be severe or anaphylactic.

Research citations

The sources behind this verdict.

1NIH / Office of Dietary Supplements. Selenium – Health Professional Fact Sheet. ods.od.nih.gov
2NIH / Office of Dietary Supplements. Selenium – Consumer Fact Sheet. ods.od.nih.gov
3other. Codex General Standard for Contaminants and Toxins in Food and Feed (CXS 193-1995, revised). fao.org
4PubMed. Barium Levels in Brazil Nuts: A Global Review of the Literature, 2025. pmc.ncbi.nlm.nih.gov
5PubMed. Radium levels in Brazil nuts: A review of the literature, 2025. pmc.ncbi.nlm.nih.gov
6FDA. CPG Sec. 570.200 Aflatoxins in Brazil Nuts, 2021. fda.gov

Independently researched8 citations