Brazil nuts have several health benefits, including promoting thyroid function, supporting the immune system, helping wounds heal, and preventing certain types of cancer, specifically cancers of the prostate, breast and bone. Brazil nuts also promote optimal muscle function, support bone and teeth health, and assist the body in using energy from food. The main nutrients in Brazil nuts that produce these health benefits include selenium, magnesium, copper and phosphorus. Brazil nuts also contain manganese, vitamin E, zinc, potassium and riboflavin.
Most of the health benefits of Brazil nuts result from the fact that one nut contains over 100 percent of the daily value of selenium, an important mineral in the body. Because ingesting high levels of selenium may be harmful, it's best to consume one serving of Brazil nuts or less each day. Some signs of excessive selenium intake include brittle hair and fingernails, skin rashes and nervous system issues. Too much selenium may also cause fatigue and diarrhea.
A 1-ounce serving of Brazil nuts, typically around five to six nuts, contains 185 calories and 18 grams of fat. Most of this fat is unsaturated fat, which can promote heart health when consumed in place of foods containing high levels of saturated fat. One serving of Brazil nuts also contains 2 grams of fiber and 4 grams of protein.