Key takeaways:
Brazil nuts come from the Amazon rainforest.
Highly nutritious, Brazil nuts contain healthy unsaturated fats, magnesium, and a high amount of the mineral selenium.
Selenium has many benefits, including brain and thyroid health. But it’s important not to get too much of it. So you shouldn’t eat more than 4 to 5 Brazil nuts per day.
Brazil nuts may or may not be on your radar. Depending on where you shop, you may have seen them in packages or in bulk bins at your local supermarket. They may be less well-known than other types of nuts. But there are plenty of reasons to become familiar with Brazil nuts.
Brazil nuts are native to the Amazon rainforest, where they grow on the Brazil nut tree. Technically, Brazil nuts are a seed, not a nut. But most people refer to them as nuts because of the way they look and the way people use them.
Brazil nuts are larger than other nuts, measuring about 1 to 2 inches long, and about a half inch wide. You may have spotted them before in a mixed nut container: They’re the largest nut in the group, with thin, brown skin on the outside. With their mild, nutty flavor, you can eat them raw or roasted.
Brazil nuts are difficult to harvest and are only found in certain parts of the world. So they’re often more expensive than other nuts. They’re sometimes harder to find in stores too. If you can’t find them in your local supermarkets, you may have better luck at a natural food store.
Brazil nuts are an excellent source of many nutrients, including:
Magnesium
Phosphorus
Vitamin E
Selenium
Highest protein nuts: Nuts alone can’t provide all of the protein that you need, but they can help contribute to your daily intake. Here are the top eight for protein.
The most heart-healthy nuts: All nuts are nutritious and can help lower your risk of heart disease. But some nuts may be better than others for heart health.
Plant-based protein sources: You don’t need to eat animal products to meet your protein requirements. But your diet should include different plant-based proteins to help bump up your protein intake.
The table below shows the nutrition benefits of a 1 oz (28 g) serving of Brazil nuts.
Calories | 187 |
Total fat | 19 g |
Saturated fat | 5 g |
Carbohydrates | 3 g |
Dietary fiber | 2 g |
Sugar | less than 1 g |
Protein | 4 g |
Phosphorous | 205 mg (16% daily value, or DV) |
Magnesium | 106 mg (25% DV) |
Selenium | 544 mcg (988% DV) |
Copper | 0.5 mg (55% DV) |
Thiamine (vitamin B1) | 0.17 mg (15% DV) |
Vitamin E | 1.6 mg (11% DV) |
Most of Brazil nuts’ health benefits come from their high selenium content. Brazil nuts contain more selenium than any other food. For example, a 1 oz serving provides nearly 1,000% of the recommended daily value (DV) of selenium. But since selenium is a nutrient that you might not be familiar with, you may be wondering, what does selenium do for the body?
Selenium is an essential trace mineral. This means your body requires it but can’t make it on its own. Selenium is needed to:
Support normal thyroid function
Produce DNA
Support healthy fertility and reproduction in both males and females
Work as an antioxidant by preventing cell damage that can increase your risk for disease
But because Brazil nuts contain so much selenium, it’s important not to eat too many at once (more on this below).
Let’s look at some of the ways that the selenium in Brazil nuts can benefit your health
Your thyroid is a butterfly-shaped gland in the front of your neck. It releases hormones that are necessary for supporting many functions in your body, including:
Metabolism
Body temperature
Growth and development
Your thyroid requires selenium to do its job properly. Selenium helps create T3, one of the two main hormones that helps the thyroid function as it should. Not getting enough selenium can contribute to thyroid disorders such as hypothyroidism and Hashimoto's thyroiditis.
Selenium also has antioxidant properties. Antioxidants help protect your body’s cells from damage. They do this by fighting off free radicals — or unstable molecules — that harm your cells. When too many free radicals build up in the body, a condition called oxidative stress can occur. Oxidative stress increases your risk of chronic health conditions such as:
Type 2 diabetes
Cancer
Heart disease
Kidney disease
Excess weight
Neurological disorders like Alzheimer’s disease and Parkinson’s disease
Eating Brazil nuts — along with other foods high in antioxidants like berries and sweet potatoes — is a great way to help protect your body from damage and disease.
The selenium in Brazil nuts also helps fight inflammation. Some research suggests that taking selenium supplements can reduce inflammation in critically ill patients. Other research has found that taking selenium may help prevent developing chronic inflammation-related diseases, such as rheumatoid arthritis, heart disease, and inflammatory bowel disease (IBD).
Selenium affects brain functions such as movement, coordination, and memory. This is because it protects against oxidative stress and inflammation — which harm brain cells. Having normal selenium levels may help lower the risk of brain disorders, including Alzheimer’s disease, Parkinson’s disease, and dementia.
This may help explain why studies have found that older adults with the lowest dietary intake of selenium had reduced cognitive performance. This means they had more trouble with thinking, remembering, and other brain skills. We also know that blood levels of selenium decline as you age.
But there’s no evidence that taking selenium supplements can help prevent brain disorders. So more research is needed.
Although Brazil nuts can benefit your health, it’s important to stick to very small quantities. With other types of nuts, you may be used to snacking on a handful or two at a time. But with Brazil nuts, the safe amount is just a few nuts.
The tolerable upper limit (UL) for selenium is 400 mcg. A single Brazil nut contains 68 mcg to 91 mcg of selenium. So, it’s important not to eat more than 4 to 5 Brazil nuts per day.
Keep in mind there may be other sources of selenium in your diet from foods, including:
Seafood (tuna, halibut, sardines, shrimp)
Meats (ham, steak, turkey, chicken, beef liver)
Grains (pasta, breads, oatmeal)
Dairy products (milk, cottage cheese, yogurt)
Eggs
Consuming too much selenium from supplements or food can lead to selenium toxicity. Symptoms can include:
Nausea
Vomiting
Nail discoloration and brittleness
Fatigue
Hair loss
Breath that smells “garlicky”
Selenium poisoning can be serious. So, it’s best to stick to eating no more than 4 to 5 Brazil nuts per day, depending on their size.
All nuts have health benefits, but which is the healthiest one may depend on your health goals:
If you want the nut with the most protein, or the most fiber, almonds are a great choice (They also have high vitamin E).
For the nut with the most omega-3 fats, choose walnuts.
For iron, choose pistachios or cashews.
There isn’t one particular food that can reduce belly fat on its own. The selenium in Brazil nuts can support a healthy metabolism. To reduce belly fat, it’s important to have an overall balanced diet combined with an active lifestyle.
It doesn’t matter what time of day you eat Brazil nuts. Just be sure not to exceed the recommended intake of 4 to 5 Brazil nuts per day.
Brazil nuts provide many essential minerals and healthy, unsaturated fats. They’re the richest food source of the mineral selenium. This mineral plays a role in supporting many parts of your body, including your thyroid and brain. Selenium also works as an antioxidant, which helps protect the body from many chronic health conditions.
But it’s important to not consume too many Brazil nuts, since getting too much selenium can cause selenium toxicity. Having just a few Brazil nuts each day can still provide many health benefits.
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Kobayashi, R., et al. (2021). Thyroid function in patients with selenium deficiency exhibits high free T4 to T3 ratio. Clinical Pediatric Endocrinology.
MacFarquhar, J. K., et al. (2010). Acute selenium toxicity associated with a dietary supplement. JAMA Internal Medicine.
Mahmoodpoo, A., et al. (2022). The effects of selenium supplementation on inflammatory markers in critically ill patients. Discover Applied Sciences.
Miragaya, J. (2024). Does selenium supplementation prevent hypothyroidism in Hashimoto’s thyroiditis? Clinical Thyroidology for the Public.
MyFoodData. (n.d.). Brazil nuts.
Office of Dietary Supplements. (2024). Selenium. National Institutes of Health.
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Turck, D., et al. (2023). Scientific opinion on the tolerable upper intake level for selenium. EFSA Journal.
World Wildlife Fund. (2010). The Brazil nut tree: Grandiose and threatened.