Brazil nuts are large nuts native to Brazil, have hard, triangular brown shells and white meats with thin brown skins and a slightly astringent flavor.
Brazil nuts are 18% protein, 13% carbohydrates, and 69% fat by weight, and 91% of their calories come from fat. The fat breakdown is roughly 25% saturated, 41% monounsaturated, and 34% polyunsaturated. Due to their high polyunsaturated fat content, primarily omega-6 fatty acids, shelled Brazil nuts soon become rancid.
Nutritionally, Brazil nuts are a good source of some vitamins and minerals. A cup (133 grams) of Brazil nuts contains the vitamins thiamin (0.8 mg—55% DV) and vitamin E (7.6 mg—38% DV); minerals calcium (213 mg—21% DV), magnesium (500 mg—125% DV), phosphorus (946 mg—96% DV), copper (2.3 mg—116% DV), and manganese (1.6 mg—81%). Brazil nuts are perhaps the richest dietary source of selenium; 28 g (1 oz, 6–8 nuts) can contain as much as 544 µg. This is 10 times the adult U.S. Recommended Dietary Allowances, more even than the Tolerable Upper Intake Level, although the amount of selenium within batches of nuts varies greatly.
Recent research suggests that proper selenium intake is correlated with a reduced risk of both breast cancer and prostate cancer. This has led some health commentators and nutritionists to recommend the consumption of Brazil nuts as a protective measure. However, these findings are inconclusive. Other investigations into the effects of selenium on prostate cancer have also been inconclusive.
Brazil nuts have one of the highest concentrations of phytic acid at 2 to 6% of dry weight. Phytic acid can prevent absorption of some nutrients, mainly iron, but is also a subject of research and possibly confers health benefits..
Despite the possible health benefits of the nut, the European Union has imposed strict regulations on the import from Brazil of Brazil nuts in their shells, as the shells have been found to contain high levels of aflatoxins, which can lead to liver cancer.
Brazil nuts contain small amounts of radium. Although the amount of radium, a radioactive element, is very small, about 1–7 pCi/g (40–260 Bq/kg), and most of it is not retained by the body, this is 1,000 times higher than in other foods. According to Oak Ridge Associated Universities, this is not because of elevated levels of radium in the soil, but due to “the very extensive root system of the tree.”
Some studies indicate that above average consumption of Brazil nuts may be a causative factor in the development of Amyotrophic lateral sclerosis or ALS (Lou Gehrig’s Disease) in some individuals.
As well as its food use, Brazil nut oil is also used as a lubricant in clocks, for making artists’ paints, and in the cosmetics industry.
Engravings in Brazil nut shells were supposedly used as decorative jewelery by the indigenous tribes in Bolivia, although no examples still exist. Because of its hardness, Brazil nut shell has often been pulverized and used as an abrasive to polish softer materials such as metals and even ceramics (in the same way as jeweler’s rouge is used). A high luster could be acquired by a final application of carnauba wax, only produced in north-eastern Brazil.
The lumber from Brazil nut trees (not to be confused with Brazilwood) is of excellent quality, but logging the trees is prohibited by law in all three producing countries (Brazil, Bolivia and Peru). Illegal extraction of timber and land clearances present a continuing threat.
To toast Brazil nuts:
Spread on a baking sheet and place in a preheated 325 degrees F (165 degrees C) oven. Toast, shaking frequently.