Is it true that eating Brazil nuts can help with weight loss? Are there other health benefits or risks of Brazil nuts

Answer:

Brazil nuts are nutritious, providing mainly good fats, carbohydrates that include a good amount of fiber, and protein.

As discussed below, Brazil nuts (which are actually seeds) also provide minerals (such as selenium, magnesium, and calcium) and some vitamin E. They have been promoted for weight loss, although the evidence is not strong. While Brazil nuts do have some radioactivity, the level is relatively small.

Brazil nuts for weight loss?

Eating Brazil nuts (along with cashews) as part of a reduced-calorie diet does not seem to improve weight loss, blood pressure or cholesterol levels, although it may have modest benefit on some body composition measures and a biomarker linked with early atherosclerosis.

An 8-week study among 29 overweight women (average age 31) with at least one additional feature of metabolic syndrome (such as high blood pressure or high triglycerides) showed that consuming an energy-restricted diet (500 Calories lower than the daily requirement) that included 15 grams of Brazil nuts (providing about 51 mcg of selenium) and 30 grams of cashews daily did not improve body weight, body mass index (BMI), waist or hip circumference, cholesterol levels or blood pressure compared to a control group that followed a similar diet without nuts. Although the Brazil and cashew nut group showed a greater reduction in percent body fat (-1.3% vs. 0.1%) and greater increases in total lean mass (1.1% vs. -0.3%) and fat-free mass (1.2% vs. -0.14%) compared to the control group, these changes were small and were considered "exploratory" outcome measures (Caldas, BJN 2022).

A good source of vitamin E and selenium?

Nuts can certainly be a good source of vitamin E, although one Brazil nut provides only 0.3 mg of vitamin E, or 2% of the recommended daily intake of 15 mg, and a 1-oz. serving (6 - 8 nuts) provides 2.1 mg or 14% of the recommended intake. Note, however, that one Brazil nut does provide the recommended daily intake for selenium.

Other nuts, such as almonds and hazelnuts, as well as certain seeds, oils and grains (sunflower seeds, safflower and olive oil and wheat germ) have higher concentrations of vitamin E. For example, a 1-oz. ounce of almonds provides 6.7 mg, and one tablespoon of wheat germ oil contains 20 mg. By incorporating some of these foods into your daily diet, you can easily meet normal daily requirements. (For more about vitamin E and vitamin E supplements, upper intake limits, amounts found in other foods, plus our tests of popular natural and synthetic vitamin E supplements, see the "ConsumerTips" and "Results" sections of the Vitamin E Supplements Review.

Radiation from Brazil nuts?

Many foods naturally contain small amounts of radioactive elements, such as radium and barium, that are absorbed by plants from the soil. However, Brazil nuts contain one of the highest concentrations of radium found in foods — approximately 1,000 times more than in other foods. In fact, the radiation from a typical 1-oz. serving of Brazil nuts (6 to 8 nuts) ranges from 0.047 to 0.08 millirem (Parekh, J Food Comp Analys 2008), which is roughly equivalent to the estimated exposure from all food and water consumed in one day (about 0.08 millirem).

However, the amount of radiation from a serving of Brazil nuts is still much lower than the estimated total daily exposure (which includes natural background radiation in the air), which is 1.7 millirem. Furthermore, it has been found that most of the radiation from Brazil nuts leaves the body, such as through feces.

So, while Brazil nuts will increase your radiation exposure, as an occasional snack this increase is not likely to be significant.