Brazil nut trees are conspicuous in the non-flooded forests of Brazil, Bolivia, and Peru. They, indeed, are one of the tallest, and long-living plant species among all the tropical rain forests. Each tree can grow up to 50 meters in height with large erect stem and wide umbrella-like foliage canopy near its top 1/3. Its lifespan is about 500 to 700 years.
Each mature tree bears up to 300 fruit pods in a season. A brazil nut pod features thick outer shell as in coconuts and may weigh up to 2.5 kg in weight. It takes about 14 months for the fruit to mature after pollination. Upon maturity, the pod falls itself from the tree, usually with a thud. The pods may remain intact even after falling from such a height. At their natural habitat, brazil nut pods exclusively depend upon caviomorph rodents (agoutis, Dasyprocta spp. that have the ability to gnaw open woody shell) to free and disperse leftover seeds for germination.
Internally, each fruit pod features 10-25 seeds (kernels), arranged in segments. Each kernel, in turn, is encased in its thick dark-brown thin shell. An edible white meat kernel features a triangular base with sloping sides, and sweet, nutty flavor and weighs about 5 g.
Brazil nuts are high in calories, contain good quantities of vitamins, anti-oxidants, and minerals. Its kernels, in fact, have been major energy sources of native Amazonians even today.
100 g of brazil nuts provide about 656 calories. Their high caloric content chiefly comes from their fats. However, much of this fat content is monounsaturated fatty acids (MUFA) like palmitoleic acid (16:1) and oleic acid (18:1) that helps lower LDL or “bad cholesterol” and increase HDL or “good cholesterol” levels in the blood. Research studies suggest that Mediterranean diet that is rich in monounsaturated fatty acids offers protection from coronary artery disease and strokes by favoring healthy blood lipid profile.
The nuts are also a great source of vitamin-E; contain about 7.87 mg per 100 g (about 52% of RDA). Vitamin-E is a powerful lipid soluble antioxidant. It required for maintaining the integrity of mucosa and skin by protecting it from harmful oxygen-free radicals.
Brazil nuts hold exceptionally high levels of selenium. 100 g nuts provide about 1917 µg, or 3485% of the recommended daily intake of selenium, rating them as the highest natural sources of this mineral. Selenium is an essential cofactor for the anti-oxidant enzyme, glutathione peroxidase. Just 1-2 nuts a day provides enough of this trace element. Adequate selenium in the diet can help prevent coronary artery disease, liver cirrhosis, and cancers.
Furthermore, just as in almonds and pine nuts, brazil nuts too are free from gluten protein. For the same reason, they are one of the popular ingredients in the preparation of gluten-free food formulas. These formula preparations are, in fact, healthy alternatives in people with wheat food allergy and celiac disease.
Additionally, these creamy nuts are an excellent source of the B-complex group of vitamins such as thiamin (51% of RDA per 100 g), riboflavin, niacin, pantothenic acid, vitamin B-6 (pyridoxine), and folates. Altogether, these vitamins work as co-factors for enzymes during cellular substrate metabolism inside the body.
In addition to selenium, they hold superb levels of other minerals such as copper, magnesium, manganese, potassium, calcium, iron, phosphorus, and zinc. Copper helps prevent anemia and bone weakness (osteoporosis). Manganese is an all-important co-factor for the antioxidant enzyme, superoxide dismutase.