TikTok Is Obsessed With Brazil Nuts—But Are They Really That Good for You?

Brazil nuts are experiencing a boom in popularity in the wellness space, with videos boasting the food’s health benefits garnering upwards of 4.2 million views on TikTok.

Packed with a ton of vitamins and minerals, it is not surprising that they are growing in popularity. They make a quick and nutritious snack that can not only boost your health but also improve thyroid function. But before you jump on the Brazil nut bandwagon, it is important to determine fact from fiction.

Experts share everything you need to know about Brazil nuts—including how you can add them to your diet, why you shouldn’t overdo it, and whether or not you need to “activate” them by soaking them in water.

What’s in Brazil Nuts?

Originating in the Amazon rainforest, Brazil nuts are shaped similarly to a kidney bean with a hard outer shell and a creamy, buttery inner seed or nut. Not only are they large and nutrient-dense, but they also are rich in selenium, which is largely due to the complex soil of the Amazon River.

“The soil content of selenium in the Amazon River basin is very high, which results in higher selenium in Brazil nuts—around 400 times more than any other nut,” explained Dinesh Edem, MD, an endocrinologist specializing in obesity management, thyroid disorders, and diabetes and director of the Weight-Loss Clinic at the University of Arkansas for Medical Sciences. “This gives Brazil nuts the unique benefit of improving health by improving selenium levels.”

Brazil nuts also are an excellent source of other minerals, as well as protein and fiber, but are mostly fat, added Kristine Dilley, RDN, CSOWM, LD a registered dietitian at The Ohio State University Wexner Medical Center.

“These [healthy] unsaturated fats and fiber in Brazil nuts are staple recommendations for improved heart health,” she noted. “However, the high fat content also makes these nuts very calorically dense, so it is important to watch portion sizes when consuming Brazil nuts.”

A serving of Brazil nuts (about two whole Brazil nuts) can offer nearly 1 gram of fiber and close to 2 grams of protein, depending on the brand and packaging. They also are a good source of vitamin E, magnesium, phosphorus, copper, and, of course, selenium.

Benefits of Selenium

The Brazil nut’s selenium makeup is primarily discussed in reference to the thyroid hormones.

“Selenium is an antioxidant and mineral that is important for the immune system and thyroid health, especially in the conversion of T4 thyroid hormone to active T3 thyroid hormone. It can also be helpful in lowering TPO antibodies found in most cases of Hashimoto’s disease,” explained Lindsay O’Reilly, RD, a registered dietitian who specializes in treating people with thyroid conditions.

If you are considering Brazil nuts for help with a thyroid condition, it is important to remember that not only is selenium deficiency rare in the United States, but improving your thyroid health extends well beyond Brazil nut consumption, said Melissa Loseke, DO, PhD, an expert in hormonal health and a medical advisor for Joi Women’s Wellness.

“Improving true thyroid health requires looking at overall gut health, cortisol levels, and glucose or insulin regulation,” Dr. Loseke continued. “The thought that adequate amounts of Brazil nuts or adding them to your daily, regular diet will correct your thyroid dysfunction, would only be looking at one piece of the whole puzzle.”

Dr. Loseke also noted that selenium goes beyond thyroid health, and can possibly reduce inflammation in the body and decreases oxidative stress, which if unbalanced can lead to cellular damage. “Brazil nuts, which also contain ellagic acid, can in combination with the selenium present, increase antioxidants leading to a decrease in neuro-inflammatory conditions such as Alzheimer’s.”

Dr. Edem agreed, “by improving antioxidant function and inflammation they [Brazil nuts] also can reduce risk of chronic diseases.”

Possible Risks of Brazil Nuts

While Brazil nuts can be beneficial to your overall health, this is definitely one case where more is not better, warned Dilley. “If you want to consume Brazil nuts, buy them 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, explained O’Reilly. According to the National Institutes of Health Office of Dietary Supplements, extremely high intakes of selenium can cause tremors, kidney failure, heart attacks, and heart failure.

“There really is no recommended intake of Brazil nuts,” O’Reilly added. “But you’ll most commonly see one to three Brazil nuts daily or a few times a week when a recommendation is made.”

The recommended dietary intake (RDI) of selenium for a healthy adult is 55 mcg, said Dilley. To put that in perspective, six to eight Brazil nuts provide 544 mcg or 989% of the daily value, which exceeds tolerable intake levels for selenium.

Dr. Edem pointed out that the soil where Brazil nuts grow also can potentially have soil contaminants like barium. “This means they can have two to three times the amount of barium compared to cashews, peanuts, and walnuts.”

However, he added that studies are mixed on how barium in Brazil nuts can impact individuals. But the potential for these contaminants may be yet another reason to limit your intake.

“Activating” Brazil Nuts

Activating Brazil nuts in water or salt water has become a popular trend based on the belief that doing so makes them more digestible, increases the bioavailability of their nutrients, and deactivates enzyme inhibitors.

“But most of the data suggests that in doing so you can turn a relatively healthy snack into a more unhealthy version,” clarified Dr. Loseke. “Whether you soak them or not, they are generally well-tolerated in the gut.”

Soaking foods is supported for things like beans, legumes, grains, or seeds, but scientific studies that have evaluated these soaking methods for nuts have shown only minimal reduction of phytate or sometimes even small increases in phytate content of the nuts tested, Dilley explained.

Adding Brazil Nuts to a Balanced Diet

“The ‘start low and go slow’ approach is always a simple and easy way to start,” suggested Dr. Loseke. “You can add just one Brazil nut a day to your diet with a meal of your choice, but it would be recommended to not exceed more than three in a day. Selenium intake should be limited to 400 mcg per day, with each Brazil nut containing between 70 to 100 mcg.”

When preparing Brazil nuts, you can eat them raw or roast them in the oven, Dilley explained. “Chopping Brazil nuts and adding them to a salad or stir-fry is a great way to add some flavor while still watching the portion size.”

The kernel and the skin have a lot of phytochemicals that have positive antioxidant effects, Dr. Edem added. “Roasted brazil nuts have more flavor, less chances of fungal contamination, and are more digestible, compared to raw Brazil nuts which have fewer calories.”

Before adding them to your diet, it is always best to talk to a healthcare provider. It also may be helpful to get a blood test to check your selenium levels—especially if you are concerned your levels are low. A healthcare provider can advise you on whether Brazil nuts are right for you—and how much you should eat per day—given your medical history and nutritional needs.