Brazil Nuts (Bertholletia excelsa) grow on Brazil nut trees known as the castanheira-do-Pará (Pará Nut tree) in Brazil. They can be found inside segments of round-shaped shells, which usually contain 12 to 20 nuts.
Regular consumption of Brazil nuts is associated with various health benefits. They are a great source of proteins, micro- and macroelements, vitamins, and fats. Because they also have a very high concentration of selenium, they boost the immune system and are said to improve the health of the brain and heart.
Brazil nut trees are native to the Amazonian forests in Peru, Brazil, Bolivia, Guyana, Venezuela, Suriname, French Guyana, Ecuador, and Colombia. The trees usually grow alongside great rivers, including the Amazonian River, the Orinoco, the Negro, and the Araguala.
Brazil nut trees face extinction and can only be found abundantly in Bolivia and Suriname
. The International Union for the Conservation of Nature classified it as a vulnerable species, while the Ministry of the Environment in Brazil considers it a threatened species.
Because Brazil nut trees require particular conditions to thrive, they can only grow in rainforests in South America. Unfortunately, it is not possible to cultivate this species in North America or Europe.
Brazil nuts are often considered a superfood. They are full of healthy nutrients that the human body needs for optimal functioning. Aside from vitamins, fats, and many beneficial compounds, brazil nuts are packed to the brim with selenium. Their concentration of this element is so high it only requires one to two nuts a day to max out the body’s demand for this microelement.
One serving of 28 grams (1 oz.) of unsalted and unroasted Brazil nuts contains 190 calories. Its primary nutrients are as follows:
1 ounce of Brazil nuts is also a source of many vitamins, micro- and macroelements:
Because Brazil nuts contain a lot of selenium, some people may experience symptoms of selenosis, a condition caused by consuming too much. To learn more about the safety of Brazil nuts, refer to the ‘Risks and side effects' Article.
Brazil nuts are rich in unsaturated fats, beneficial chemical elements, and acids that positively affect various body parts. The best-researched properties are as follows:
Some studies show Brazil nuts may have anti-depressant and neuroprotective effects on humans. This is possibly caused by ellagic acid, a polyphenol in Brazil nuts. However, the results could be more extensive and require more research.
Another study suggests that selenium, found in abundance in Brazil nuts, may be responsible for improving the performance of brain signaling pathways, including GABA (Gamma-aminobutyric acid) and dopamine signaling. These two signaling pathways are essential in Alzheimer's and Parkinson's diseases, as low selenium levels have been associated with neurodegenerative conditions.
On the other hand, one study found that low selenium levels are unrelated to human cognitive impairment. Researchers have yet to reach a consensus and need more high-quality evidence to prove such a link exists.
Selenium present in Brazil nuts may aid the thyroid in performing its tasks. The tissue of this organ has the highest concentration of selenium in the body. Low levels of this element can cause a bad mood, worsen concentration, negatively affect metabolism, make it challenging to have a good night's sleep, and, last but not least, reduce thyroid activity.
Selenium is a critical component the thyroid gland requires to convert T4 (thyroxine hormone) into T3 (triiodothyronine hormone). Not enough selenium may lead to cellular damage and increases the risk of developing autoimmune disorders such as Graves' disease or Hashimoto's thyroiditis and thyroid issues like hypothyroidism.
According to a large study conducted in China, people with selenium deficiency are more likely to develop thyroid diseases (enlarged thyroid, thyroiditis, hypothyroidism).
The risk of developing all of the above health problems can be significantly reduced by eating just one Brazil nut per day.
There are reasons to believe that Brazil nuts are also suitable for heart health. They contain phytonutrients, antioxidants, soluble fiber, and polyunsaturated and monounsaturated fatty acids, all beneficial for heart performance.
Brazil nuts help maintain proper blood pressure and increase healthy cholesterol (HDL) levels, which reduces the risk of stroke, heart attack, and heart diseases like heart cancer.
The above properties of Brazil nuts were partially confirmed in the study conducted in 2019. Its results suggest that the consumption of Brazil nuts decreases the chance of developing cardiovascular health issues and experiencing heart attacks in people with diabetes.
Brazil nuts may help to deal with inflammation in the body. It consists of several components which have anti-inflammatory properties:
One of the roles of the above substances is to fight free radicals causing damage to the body cells. Making sure to have a diet rich in antioxidants allows cells to be healthy and perform their functions properly.
A small study conducted in 2019 provided some evidence of the anti-inflammatory properties of Brazil nuts. According to its results, consuming just one Brazil nut daily for three months reduced inflammation in chronic kidney disease patients. The level of oxidative stress decreased among these patients.
The study was followed up by more research which found that once the daily intake of Brazil nuts is discontinued, inflammatory markers return to their original values. That suggests that the nuts' consumption should be long-term to maintain its benefits related to oxidative stress.
In addition to anti-inflammatory and antioxidant properties, Brazil nuts are also referred to as anti-cancer snacks. Again, thanks to selenium and ellagic acid presence, consuming nuts can lower the chance of developing cancer.
According to many researchers, selenium can decrease the presence of mercury (Hg), a toxic chemical element, which is correlated with the growth of cancerous cells. However, these results regard only animal studies, which need more comprehensive evidence to reach a consensus among health professionals. More high-quality, long-term studies may shed more light on this problem in the future.
Low selenium levels are linked to anxiety and depression. Certain mood-affecting disorders are more likely to develop if your selenium intake exceeds recommended amounts.
One study found that symptoms of anxiety, depression, and tiredeness subside after five weeks of recommended daily selenium intake (100mcg), equivalent to 1-2 Brazil nuts, depending on the brand.
The list of selenium benefits goes on and also includes a positive impact on blood sugar levels.
One 8-week-long study found that the daily intake of 200 mcg of selenium improves insulin sensitivity and reduces insulin levels in people with coronary heart disease and type 2 diabetes.
Another study also found that consuming one Brazil nut daily lowers cholesterol levels in healthy adults.
Brazil nuts have a lot of calories for their size, but it does not stop them from helping your digestive system perform its tasks more effectively—all thanks to an impressive amount of healthy fats in the seeds.
They also contain plenty of dietary fiber that will make you feel full for a long time and amino acid arginine that will additionally support calorie-burning processes in your body. As long as you won’t eat an entire package all at once, you can expect Brazil nuts to help you maintain proper weight and body fat levels.
Brazil nuts are heavily packed with nutrients, which makes them easy to overdose. A few nuts per day is recommended, but some people do not experience any side effects after eating more.
Brazil nuts have a lot of calories and a high concentration of selenium. Overeating may lead to weight gain and cause selenium toxicity.
Moreover, some people may experience allergic reactions to nuts, including Brazil nuts. The American College of Allergy, Asthma & Immunology estimates that 25 to 40 percent of peanut allergy people experience side effects after eating at least one species of nuts.
Most drawbacks of Brazil nut consumption are related to their high selenium levels—a spoonful of tar to this microelement's plethora of excellent properties.
Brazil nuts are safe to eat if a person does not exceed their daily selenium intake too much. Although 1 to 2 nuts are enough to max out the need for selenium, eating more is usually completely safe. The problems arise when consuming large quantities of Brazil nuts during the day. Take a look at the below symptoms of selenium overdose (selenium toxicity) to see if maybe you should reduce the amount you eat per day:
If you still experience symptoms after reducing the intake of Brazil nuts, discuss your issues with a dietician or discontinue consuming nuts.
Brazil nuts are called superfoods, not without reason. They are rich in nutrients that support the brain, heart, and thyroid. One Brazil nut is enough to meet daily requirements for selenium, a chemical element that helps lower blood sugar levels, increase the performance of the thyroid gland and help overcome inflammation and combat free radicals/
After considering their benefits, it can be safely said that there is much to gain and little to lose. The only drawback is related to selenium toxicity, but this problem can be easily overcome by reducing the amount of nuts consumed.
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