Calories in Brazil Nuts: Full Nutrition Breakdown

Brazil nuts are large, crescent-shaped tree nuts harvested from towering trees in the Amazon rainforest of South America. One ounce of dried Brazil nuts (about 6 nuts) provides approximately 187 calories, 4.1 grams of protein, and 19 grams of fat, but their most remarkable nutritional feature is their extraordinary selenium content — a single nut provides well over 100 percent of the daily recommended intake. They are also an excellent source of magnesium, copper, phosphorus, manganese, and thiamine.

Calories by serving size:

Brazil nuts are the richest known dietary source of selenium, with a single nut (approximately 5 grams) providing about 96 micrograms — roughly 175 percent of the daily recommended intake of 55 micrograms for adults. Selenium is a critical trace mineral that supports thyroid hormone metabolism, DNA synthesis, and the body's antioxidant defense system through selenoproteins like glutathione peroxidase. The fat in Brazil nuts is predominantly polyunsaturated (about 36 percent) and monounsaturated (about 37 percent), with a relatively higher saturated fat content (about 25 percent) compared to most other tree nuts.

Frequently Asked Questions (FAQ)

How many Brazil nuts should you eat per day?

Most nutrition experts recommend limiting Brazil nut intake to 1 to 3 nuts per day due to their extremely high selenium content. A single Brazil nut contains approximately 96 micrograms of selenium, and the tolerable upper intake level for adults is 400 micrograms per day — meaning that eating more than 4 to 5 nuts daily could approach levels associated with selenium toxicity (selenosis). Symptoms of chronic selenium excess include brittle nails, hair loss, garlic-scented breath, gastrointestinal upset, and fatigue. Eating 1 to 2 Brazil nuts daily is generally considered a safe and effective way to meet selenium needs without supplementation.

What are the symptoms of selenium toxicity from eating too many Brazil nuts?

Selenium toxicity, or selenosis, can occur from chronically consuming more than 400 micrograms of selenium per day, which is possible by eating just 5 or more Brazil nuts daily over time. Early symptoms include a metallic or garlicky taste in the mouth, brittle or discolored nails, and hair loss or brittleness. More severe toxicity can cause gastrointestinal distress, fatigue, irritability, neurological symptoms, and in extreme cases, respiratory and cardiac complications. If you eat Brazil nuts regularly, it is important to be aware of other selenium sources in your diet (such as seafood, organ meats, and fortified grains) to avoid exceeding safe levels.

Are Brazil nuts good for thyroid health?

Brazil nuts are one of the most effective foods for supporting thyroid function because the thyroid gland has the highest selenium concentration of any organ in the body. Selenium is essential for the production and activation of thyroid hormones — specifically, the selenoprotein enzyme type II deiodinase converts the inactive thyroid hormone T4 into the active form T3. Studies have found that selenium supplementation (including from Brazil nuts) can reduce thyroid antibody levels in people with Hashimoto's thyroiditis and may help improve symptoms of autoimmune thyroid disease. Consuming just 1 to 2 Brazil nuts daily has been shown in clinical trials to effectively raise selenium status and improve markers of thyroid function.

Why can Brazil nuts only be harvested from the wild?

Brazil nut trees (Bertholletia excelsa) grow almost exclusively in undisturbed Amazon rainforest because they depend on a complex ecological web for pollination and reproduction that cannot be replicated in plantation settings. The trees are pollinated primarily by large-bodied orchid bees (Eulaema species), which require intact forest habitat to survive. Additionally, the seeds are dispersed by agoutis — small rodents with jaws strong enough to gnaw through the extremely hard seed pod — which bury the nuts and allow some to germinate into new trees. This ecological dependency means that Brazil nut harvesting actually incentivizes rainforest preservation, making them one of the most sustainable wild-harvested foods in the world.

How do Brazil nuts compare to selenium supplements?

Studies have shown that selenium from Brazil nuts is absorbed as efficiently as, or even more efficiently than, selenium from dietary supplements. A clinical trial published in the American Journal of Clinical Nutrition found that consuming just 2 Brazil nuts per day raised blood selenium levels and improved glutathione peroxidase activity as effectively as a 100-microgram selenium supplement. Food-based selenium from Brazil nuts comes packaged with other beneficial nutrients including healthy fats, protein, magnesium, and additional antioxidants that supplements do not provide. However, the selenium content of Brazil nuts can vary significantly (from 10 to over 100 micrograms per nut) depending on the soil where they were grown, making precise dosing more challenging compared to standardized supplements.