Contain Antioxidants
Selenium is an antioxidant that’s important for the immune system and thyroid health, especially in the conversion of T4 thyroid hormone to active T3 thyroid hormone. The mineral can also be helpful in lowering TPO antibodies found in most cases of Hashimoto’s disease.5 This thyroid disease causes inflammation that results in hypothyroidism, or decreased thyroid function.6
Keep in mind that thyroid health requires looking at overall gut health, cortisol levels, and glucose (sugar) or insulin regulation.78 The thought that adding these nuts to your daily, regular diet will correct a thyroid problem would only be looking at one piece of the puzzle.
Improving your thyroid health extends well beyond Brazil nut consumption. Brazil nuts’ antioxidant content can also reduce the risk of several diseases.9 As an antioxidant, selenium helps decrease oxidative stress, which can lead to cell damage if unbalanced. Research has shown that this cell damage may contribute to the onset of illnesses like cancer, diabetes, and heart disease.2
May Reduce Inflammation
Antioxidants like selenium go beyond thyroid health and can also possibly reduce inflammation in the body.1 Chronic (long-term) inflammation may increase your risk of cancer, diabetes, and heart disease. Reducing inflammation might protect against these illnesses.2
Selenium also increases levels of glutathione peroxidase (GPx), an enzyme that helps decrease inflammation and oxidative stress.10
Can Help With Cognition
Brazil nuts are a source of selenium and ellagic acid, both of which may support cognitive health. Ellagic acid is a polpyhenol, or a compounds with anti-inflammatory and antioxidant properties. Research has shown that ellagic acid may protect brain health.11
Some evidence suggests that low levels of selenium may contribute to illnesses that negatively impact cognition, such as Alzheimer’s disease. Increasing selenium levels may improve reasoning and thinking. A study published in 2022 found that cognition improved among older adults who ate one Brazil nut daily for six months.4
May Improve Blood Sugar Regulation
Selenium has been shown to improve insulin sensitivity, thus decreasing blood sugar levels, in people with type 2 diabetes.3 Insulin is a hormone that helps move glucose into the cells. Insulin resistance, in which the cells do not respond to insulin, is a hallmark characteristic of type 2 diabetes.12
Nutrition of Brazil Nuts
A serving of Brazil nuts (about two whole nuts) can offer the following nutrients:13
- Calories: 62
- Fat: 6 grams (g)
- Saturated fat: 1.5 g
- Unsaturated fat: 4.5 g
- Sodium: 0.28 milligrams (mg)
- Carbohydrates: 1.11 g
- Fiber: 0.71 g
- Added sugars: 0 g
- Protein: 1.35 g
Brazil nuts are rich in vitamin E, magnesium, phosphorus, copper, and selenium. These nuts are also a source of unsaturated fats and fiber essential for heart health.13 The high fat content also makes these nuts very calorically dense. It’s important to watch portion sizes when consuming Brazil nuts.
Risks
Brazil nuts can be beneficial to your overall health, but it’s important to eat them in moderation. You might buy these nuts in small quantities and use them less than daily to prevent excess selenium intake.
Overconsuming Brazil nuts pose a number of health risks, such as selenium toxicity. This might look like diarrhea, nausea, a metallic taste in the mouth, and hair loss, among other symptoms. Extremely high intakes of selenium can cause tremors, kidney failure, heart attacks, and heart failure.1
There really is no recommended intake of Brazil nuts. The recommended dietary intake (RDI) of selenium for a healthy adult is 55 micrograms (mcg). Six to eight Brazil nuts provide 544 mcg, or 989% of the daily value (DV), which exceeds tolerable intake levels for selenium.1
The soil where Brazil nuts grow can also potentially contain soil contaminants like barium. This means they can have two to three times the amount of barium compared to cashews, peanuts, and walnuts.14 Studies are mixed on how barium in Brazil nuts can impact humans. The potential for these contaminants may be yet another reason to limit your intake.
Tips for Consuming Brazil Nuts
It’s always best to talk to a healthcare provider before adding Brazil nuts to your diet. It also may be helpful to get a blood test to check your selenium levels, especially if you are concerned yours are low. A healthcare provider can advise you on whether Brazil nuts are right for you and how much you should eat per day.
Here are some different ways you can prepare Brazil nuts:
- Chop the nuts and add them to a salad or stir-fry to add some flavor while still watching the portion size
- Eat them raw or roast them in the oven
- Roast the nuts to add flavor, decrease the risk of fungal contamination, and make them more digestible
Activating Brazil nuts in water or salt water has become a popular trend. Some claim that activating the nuts makes them more digestible, increases the bioavailability of their nutrients, and deactivates enzyme inhibitors. Soaking foods is supported for foods like beans, legumes, grains, or seeds. Some evidence suggests that these soaking methods for nuts have shown only minimal effects.15
Brazil nuts are also generally well-tolerated in the gut, whether or not you soak them. You can add just one Brazil nut a day to your diet with a meal of your choice, steadily increasing to about three per day.
A Quick Review
Brazil nuts are a rich source of selenium, an antioxidant. Selenium can reduce inflammation, help improve blood sugar regulation, and help with cognition. Eating too many Brazil nuts can lead to selenium toxicity, which has symptoms like diarrhea, nausea, and a metallic taste in the mouth. Limiting intake to about one to three Brazil nuts per day is best.
Talk to a healthcare provider or registered dietitian nutritionist if you’re unsure whether Brazil nuts are safe for you.
