Rich in minerals and bursting with healthy fats, the Brazil Nut is nature’s highest known source of the vital nutrient selenium – a compound that is crucial to many bodily functions. Dietary selenium (as opposed to supplements), is readily absorbed with a bioavailability of over 50 percent.
Selenium is an essential component to the smooth functioning of the thyroid, helping to regulate the amount of the thyroid hormone T3 that is produced within the body. Without selenium the T3 hormone cannot be produced which can be catastrophic to a wide variety of bodily systems.
Research has shown that eating just one Brazil nut per day is enough to raise T3 hormone levels naturally. A 2015 study gave patients with poor thyroid function one Brazil Nut per day for 3 months. After the 3 month period their thyroid hormone levels had significantly increased and levels of thyroid stimulating hormone (TSH) reduced.1
Selenium is also needed for the proper functioning of the immune system. Without enough of this important mineral, the immune system is weak in the face of attack. People with low selenium levels are more likely to come down with frequent infections and take longer to get over them.
Brazil Nuts are also rich in ellagic acid, a potent anti-inflammatory compound that also has neuroprotective qualities. It is well known that constant low-level inflammation is a pre-cursor to many diseases.
Many of Brazil Nut’s benefits come from its rich selenium content, and its contribution to fertility is no exception. Selenium is a key element in spermatogenesis (the production or development of mature spermatozoa), and naturally boosts testosterone levels.
Researchers published a double blind study in 2017 entitled the “Effect of Selenium in Treatment of Male Infertility”. They gave 12 infertile men one 50 mcg capsule of selenium daily for 3 months. At the end of this period they found a significant increase in sperm count, motility, viability, normal sperm morphology and ejaculation volume of infertile men after treatment with selenium.2
Female fertility is also heavily influenced by adequate selenium levels. A medical research team, led by Melanie Ceko, looked at the role of selenium in the ovaries, and found that selenium is crucial to the development of healthy ovarian follicles. Follicles are responsible for production of eggs in women.
The researchers found exactly where selenium is located in the ovary, and in particular, the selenoprotein known as GPX1.
According to Ceko:
"Our findings are important, because they show that selenium and selenoproteins are at elevated levels in large, healthy ovarian follicles. We suspect they play a critical role as an antioxidant during the late stages of follicle development, helping to lead to a healthy environment for the egg, We found that gene expression of GPX1 was significantly higher – in some cases double – in egg cells that yielded a pregnancy."
The researchers cautioned that more research is needed to understand how to optimise selenium for fertility, and that it is not just a matter of taking more selenium supplementation.
Folklore and history
Consumed as a food staple by the indigenous peoples since the Upper Palaeolithic era 11,000 years ago, Brazil Nuts have a long history of traditional use. The oil was extracted to be used as cooking oil, for skin, hair and made into soap. The seed pods were used as cups and to make small fires to drive away black flies.
As a medicinal herb, the native Amazonian tribes made a decoction of the tree bark to cure liver disorders. In traditional Brazilian herbal medicine, a tea prepared of the seed husks is used to alleviate stomach aches and for other stomach complaints.
Native to South America, the Brazil Nut tree lives for over 500 years, with some specimens reaching and impressive 1,000 years old. Growing to 50 metres tall and with a trunk circumference of up to 2 metres, it is the one of the largest trees of the Amazon Rainforest.
Brazil Nuts are technically classified as seeds because the come from large pods containing between 10 and 24. Botanically, they are more closely related to blueberries and persimmons than pecans and walnuts!
Organic Brazil Nuts
Delicious when eaten whole or crushed and added to muesli, flapjacks and in baking.
Carbohydrates, protein, fat, fibre, selenium, magnesium, copper, phosphorus, manganese, zinc, calcium, potassium, iron, vitamin B1 and vitamin E
Do not consume if you have a nut allergy.