What the evidence says. Early or small human trials; promising but not yet conclusive.
Nutrition per serving 1 oz (28 g, ~6 nuts)
Sugars0.7 g3%
Fibre2.1 g8%
Other carbs0.5 g2%
Protein4 g14%
Fat18.8 g67%
Other1.9 g7%
What's in one serving, by weight — average composition (USDA).One serving as % of the adult daily requirement (FDA Daily Values). The bold outer ring = 100% of a day's needs.
Brazil Nut (Bertholletia excelsa) is a nut or seed used for modest reductions in total and ldl cholesterol in small rcts. NutriDex grades the human evidence as Preliminary. Brazil nuts are the most concentrated dietary source of selenium, and most of the specific human research focuses on that. Small randomized trials suggest a modest benefit: a 90-day RCT of partially defatted Brazil nut flour in dyslipidemic patients lowered total and non-HDL cholesterol (Carvalho 2015, PMID 26077768), and a trial in obese adolescents reduced total/LDL cholesterol and oxidized LDL (Maranhao 2011, PMID 21619692). A 2022 systematic review and meta-analysis of RCTs found Brazil nuts reliably raise selenium status but showed inconsistent, generally small effects on blood lipids (PMID 35204285). Evidence is preliminary and rests on small, short trials; there are no Brazil-nut-specific outcome trials for cardiovascular events or mortality. The stronger cardiovascular and all-cause mortality data come from tree nuts as a whole and from large cohorts (Aune 2016 meta-analysis, PMID 27916000), not Brazil nuts specifically. Treat them as one nutritious nut among many, valued chiefly for selenium.
Purported Benefits
✓Modest reductions in total and LDL cholesterol in small RCTs
✓Dramatically raises blood selenium status from a tiny serving
✓Lowers oxidized LDL and markers of oxidative stress in trial subjects
✓Part of the broader tree-nut pattern linked to lower CVD risk in cohorts
✓Provides healthy unsaturated fats, fibre and magnesium
Tree nuts are a major allergen and can cause life-threatening anaphylaxis; avoid if allergic to tree nuts. Brazil nuts are calorie-dense (~185 kcal/oz), so portion control matters. The dominant Brazil-nut-specific risk is selenium toxicity (selenosis): a single nut can contain 70-90 mcg selenium, so just a few nuts can exceed the 400 mcg/day tolerable upper limit, causing hair loss, brittle nails, GI upset, garlic breath, fatigue and neuropathy. Limit to 1-3 nuts per day and do not combine with selenium supplements. Whole nuts are a choking hazard for young children. Brazil nuts can also concentrate naturally occurring radium and barium from soil; this is not a practical concern at normal intakes but is another reason not to over-consume. Educational only — always check with your doctor or pharmacist before combining Brazil Nut with any medicine.
Brazil Nut is most often taken for Modest reductions in total and LDL cholesterol in small RCTs, Dramatically raises blood selenium status from a tiny serving, Lowers oxidized LDL and markers of oxidative stress in trial subjects, Part of the broader tree-nut pattern linked to lower CVD risk in cohorts. Selenium-rich tree nut; 1-2 nuts/day for lipids, but easy to overdose
Does Brazil Nut work — what does the evidence say?
Preliminary evidence. Early or small human trials; promising but not yet conclusive. Brazil nuts are the most concentrated dietary source of selenium, and most of the specific human research focuses on that. Small randomized trials suggest a modest benefit: a 90-day RCT of partially defatted Brazil nut flour in dyslipidemic patients lowered total and non-HDL cholesterol (Carvalho 2015, PMID 26077768), and a trial in obese adolescents reduced total/LDL cholesterol and oxidized LDL (Maranhao 2011, PMID 21619692). A 2022 systematic review and meta-analysis of RCTs found Brazil nuts reliably raise selenium status but showed inconsistent, generally small effects on blood lipids (PMID 35204285). Evidence is preliminary and rests on small, short trials; there are no Brazil-nut-specific outcome trials for cardiovascular events or mortality. The stronger cardiovascular and all-cause mortality data come from tree nuts as a whole and from large cohorts (Aune 2016 meta-analysis, PMID 27916000), not Brazil nuts specifically. Treat them as one nutritious nut among many, valued chiefly for selenium.
What is the typical dose of Brazil Nut?
1-2 nuts (~5-10 g) per day; even a single nut supplies ~70-90 mcg selenium. Do not exceed 3-4 nuts daily.
Is Brazil Nut safe? Any cautions or side effects?
Tree nuts are a major allergen and can cause life-threatening anaphylaxis; avoid if allergic to tree nuts. Brazil nuts are calorie-dense (~185 kcal/oz), so portion control matters. The dominant Brazil-nut-specific risk is selenium toxicity (selenosis): a single nut can contain 70-90 mcg selenium, so just a few nuts can exceed the 400 mcg/day tolerable upper limit, causing hair loss, brittle nails, GI upset, garlic breath, fatigue and neuropathy. Limit to 1-3 nuts per day and do not combine with selenium supplements. Whole nuts are a choking hazard for young children. Brazil nuts can also concentrate naturally occurring radium and barium from soil; this is not a practical concern at normal intakes but is another reason not to over-consume.
How many studies support Brazil Nut?
NutriDex cites 12 sources for Brazil Nut, graded "Preliminary".
Cite this page
APA
Peh, D. (2026). Brazil Nut (Bertholletia excelsa): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 16 Sept 2026, from https://nutridex.info/s/brazil-nut
BibTeX
@misc{nutridex_brazil_nut,
author = {Peh, Daryl},
title = {Brazil Nut (Bertholletia excelsa): Benefits, Dosage, Side Effects \& Evidence},
year = {2026},
howpublished = {NutriDex --- The Supplement Research Compendium},
url = {https://nutridex.info/s/brazil-nut},
note = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-09-16}
}
For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.