Brazil nut

Studies in people

• Benefit

  Heart and blood sugar health⁴

  In people, eating brazil nuts in a usual diet raised antioxidant markers, and healthy people also improved cholesterol and fasting glucose.

• Open question

  Blood cholesterol levels⁵

  In people, eating Brazil nuts raised selenium levels but did not change cholesterol.

• Benefit

  Heart and cholesterol health⁷

  Brazil nuts contain selenium and other nutrients, and studies found they may improve cholesterol and antioxidant response.

• Benefit

  Gut inflammation and leaky gut⁸

  In women with overweight, eating brazil nuts daily alongside a diet cut inflammation and improved gut leakage.

• No harm found

  Heart health in patients¹⁰

  In people with heart disease, eating one Brazil nut daily for 3 months did not change their TMAO levels.

• Benefit

  Cholesterol levels¹¹

  In people, eating Brazil nut flour alongside a healthy diet lowered total and non-HDL cholesterol.

• Benefit

  Memory and thinking in older adults¹²

  In older people with mild memory problems, eating one Brazil nut daily improved some thinking test scores.

• Open question

  Selenium levels in dialysis patients¹³

  In dialysis patients, eating one Brazil nut a day raised low selenium levels, but they fell again a year later.

• Benefit

  Blood sugar and DNA damage¹⁵

  In people with type 2 diabetes, eating one Brazil nut a day for six months lowered blood sugar and DNA damage.

• Benefit

  Benefits fade after stopping¹⁷

  In people on dialysis, one Brazil nut a day lowered inflammation markers, but levels rose again a year after stopping.

• Open question

  Nut allergy diagnosis¹⁹

  In people suspected of Brazil nut allergy, history, skin tests and blood tests together diagnosed most cases.

Found in some samples or products

These come from where it was grown, how it was processed or cooked, or what it was made into. They are not about the ingredient itself, so the signal does not count them.

• Barium in a popular nut²

  Brazil nuts can hold barium, and eating two a day may be too much for some people.

• Cancer risk from daily eating³

  Brazil nuts hold tiny amounts of natural radioactivity, and scientists do not yet know whether eating them daily affects cancer risk.

• Heavy metals in the blood¹⁶

  Obese women who ate one Brazil nut daily for two months had more cadmium in their blood.

Single cases of misuse or overdose

One person or one incident, such as an accidental overdose or a mistake in a kitchen or factory. They are real, but a single case does not show what happens at normal amounts, so the signal does not count them.

• Pancreas and blood fats⁹

  A woman got sudden pancreas problems after taking a Brazil nut weight loss supplement every day.

How it’s made and used

• Selenium in the diet⁶

  Brazil nuts are one of the richest food sources of selenium, which the body needs.

• Selenium levels in vegans¹⁴

  Eating Brazil nut butter raised selenium levels in vegans and omnivores as much as a supplement did.

• Selenium levels in the body¹⁸

  Eating two Brazil nuts a day raised selenium levels in people as much as selenium supplements did.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.