A Bertholletia excelsa, também conhecida como castanheira do Pará ou castanheira do Brasil, pode ser encontrada nas florestas que circundam os grandes rios Amazonas, Negro, Tocantins, Orinoco e Araguaia. Com uma presença em todos os países amazónicos, ela abunda especialmente na Bolívia e no Suriname. Esta espécie vulnerável enfrenta vários riscos, encontrando-se ameaçada pela desflorestação causada na sua maior parte pela atividade humana. O fruto da castanheira do Pará precisa de mais de um ano para amadurecer, apresentando o tamanho de um coco e um peso até 2 Kg. A sua casca é dura e contém no seu interior entre 8 a 24 sementes, designadas por castanhas do Pará ou castanhas do Brasil. As castanheiras do Pará podem viver 500 ou mais anos. O maior exportador é a Bolívia, onde é designada por "almendras". De elevado teor calórico e proteico, uma simples castanha fornece a dose diária de selénio necessária para o nosso organismo.
The Brazil nut (Bertholletia excelsa, family Lecythidaceae) is an important economic plant of the Amazon. The edible seeds of this species, along with the latex of Hevea brasiliensis, are often cited as the most important products of extractive reserves in Amazonia.
To be on the safe side and because we could not find any definitive study on extended long term effects relative to any nut consumption, we must rely on the good sense of so many other studies which do confirm that nuts are beneficial to our health. So, in this sense, three to five Brazil nuts each month (natural and unsalted) would be the beneficial recommended serving size. Remember that there are so many other nuts and seeds beneficial to our health, that we must be reasonable when recommending any monthly advisable ingestion of something. And we must bear in mind that many other animal and plant foods contain selenium, even if in much less concentration than Brazil nuts.
Brasil nuts are rich in Selenium which provides protection against cardiovascular diseases. Selenium helps improve the working of the immune system, promoting the synthesis of glutathione, fortifying the protection against bacterial and viral infections which plays an important role in minimizing free radical damage and lower the rates of breast cancer. The proper functioning of the thyroid gland needs also Selenium.
Selenium is also known to boost testosterone levels, improving sperm production and motility.
Brasil nuts help also in controlling weight. The high protein and fiber content of these nuts help to control hunger and facilitate peristaltic motion in the gastrointestinal system which helps prevent gastric ulcers, bloating, constipation, cramps and even colon cancer. One study from University of Arizona and Cornell University showed that, “patients receiving selenium had a 63% decrease in cancer of the prostate, a 58% decrease in colon or rectal cancer and a 46% decrease in lung cancer.”
The mono unsaturated and polyunsaturated fats in Brazil nuts can also reduce the heart attack and stroke risk, helping also to prevent atherosclerosis.
The high content of zinc in Brasil nuts is benefic and helpful for anyone which has zinc deficiency.
Selenium enables a healthy cholesterol ratio by helping to raise HDL (high density lipoproteins or good cholesterol) and lower LDL (bad cholesterol).
The vitamin and nutrients make Brasil nuts a benefit towards the protection of your skin elasticity and even on the treatment of acne. Selenium is also responsible for the stimulation of the antioxidant glutathione compound that is responsible for removing free radicals from the skin cells, a cause for wrinkles and sometimes skin cancer.
Bad effects for your health
Too much selenium will bring you problems. An overdose of Selenium can be toxic, it will mean too much carcinogenic aflatoxins and these can cause hair falling, whiting of nails, fatigue, stomach problems, rash, anxiety disorders, asthma, depression, heart disease, rheumatoid arthritis and seizures.
Be sure to test yourself against any potential Brazil nut allergies before consuming them natural or in oil form or other more potent form.
Because of high fat content, Brazil nuts can go rancid very easily. You should store them in the freezer to maintain their freshness. Heat, light, and humidity will also spoil the nuts. When they are still in the shell, you can keep them for three months at room temperature in a cool dry place. You can also store them properly inside a plastic bag or freezer container and they will keep up for almost one year inside the refrigerator or freezer without affecting flavor or texture.
Selecionámos a seguir algumas páginas que poderão fornecer informação adicional relativamente a esta imponente árvore: Castanheira do Párá ou Castanheiro do Brasil e seus frutos.
Metabolomics Unveils Urinary Changes in Subjects with Metabolic Syndrome following 12-Week Nut Consumption
Sara Tulipani, Rafael Llorach, Olga Jáuregui, Patricia López-Uriarte, Mar Garcia-Aloy, Mònica Bullo, Jordi Salas-Salvadó, CristinaAndrés-Lacueva;Department of Nutrition and Food Science, XaRTA, INSA, Faculty of Pharmacy, University of Barcelona, Barcelona, Spain; INGENIO−CONSOLIDER Program, Fun-c-food CSD2007-063, Ministry of Science and Innovation, Barcelona, Spain; Scientific and Technical Services, University of Barcelona, Spain; Human Nutrition Unit, IISPV, Universitat Rovira i Virgili, Reus, SpainCIBERobn, Instituto Carlos III, Madrid, Spain; J. Proteome Res., 2011, 10 (11), pp 5047–5058DOI: 10.1021/pr200514h; Publication Date (Web): September 12, 2011
Association of Nut Consumption with Total and Cause-Specific Mortality
Ying Bao, M.D., Sc.D., Jiali Han, Ph.D., Frank B. Hu, M.D., Ph.D., Edward L. Giovannucci, M.D., Sc.D., Meir J. Stampfer, M.D., Dr.P.H., Walter C. Willett, M.D., Dr.P.H., and Charles S. Fuchs, M.D., M.P.H.; N Engl J Med 2013; 369:2001-2011;November 21, 2013; DOI: 10.1056/NEJMoa1307352
Primary Prevention of Cardiovascular Disease with a Mediterranean Diet
Ramón Estruch, M.D., Ph.D., Emilio Ros, M.D., Ph.D., Jordi Salas-Salvadó, M.D., Ph.D., Maria-Isabel Covas, D.Pharm., Ph.D., Dolores Corella, D.Pharm., Ph.D., Fernando Arós, M.D., Ph.D., Enrique Gómez-Gracia, M.D., Ph.D., Valentina Ruiz-Gutiérrez, Ph.D., Miquel Fiol, M.D., Ph.D., José Lapetra, M.D., Ph.D., Rosa Maria Lamuela-Raventos, D.Pharm., Ph.D., Lluís Serra-Majem, M.D., Ph.D., Xavier Pintó, M.D., Ph.D., Josep Basora, M.D., Ph.D., Miguel Angel Muñoz, M.D., Ph.D., José V. Sorlí, M.D., Ph.D., José Alfredo Martínez, D.Pharm, M.D., Ph.D., and Miguel Angel Martínez-González, M.D., Ph.D., for the PREDIMED Study Investigators;N Engl J Med 2013; 368:1279-1290 April 4, 2013DOI: 10.1056/NEJMoa1200303
Changes in Diet and Lifestyle and Long-Term Weight Gain in Women and Men
Dariush Mozaffarian, M.D., Dr.P.H., Tao Hao, M.P.H., Eric B. Rimm, Sc.D., Walter C. Willett, M.D., Dr.P.H., and Frank B. Hu, M.D., Ph.D.; N Engl J Med 2011; 364:2392-2404; June 23, 2011DOI: 10.1056/NEJMoa1014296
Chemical Composition of Selected Edible Nut Seeds
Mahesh Venkatachalam andShridhar K. Sathe; Department of Nutrition, Food & Exercise Sciences, Florida State University, Tallahassee, Florida 32306-1493; J. Agric. Food Chem., 2006, 54 (13), pp 4705–4714; DOI: 10.1021/jf0606959; Publication Date (Web): May 28, 2006