Don’t overeat them — you could make yourself seriously ill

This article is for educational and entertainment purposes only. It is not medical advice. If you need medical advice, please consult a qualified medical practitioner.

Most people know that nuts are generally considered to be a healthy snack. But did you know that one nut, in particular, contains a significant amount of radium?

Brazil nuts come from the Bertholletia excelsa tree that grows mainly in the Amazon forest. The fruits that grow on the trees are hard-shelled pods, similar to coconuts. Inside the fruit are the seeds, which we know as Brazil nuts. There are usually around 8–24 nuts per pod.

The pods are not picked from the tree as most other nuts are. Instead, the pods are gathered from the forest floor. This ensures that the trees are not disturbed or damaged.


The Brazil nut trees have very deep roots that soak up large amounts of radium from the soil. Radium is a source of radiation, which can cause cancer in large amounts.

The radiation present in Brazil nuts is 1,000 times higher than in most other foods.

But don’t get too worried. Eating 1–3 Brazil nuts a day shouldn’t cause any health risk.

Annual radiation exposure is measured in MilliSieverts (mSv). Cancer risk is increased if your exposure is over 100 mSv.

To put this into perspective, eating one ounce of Brazil nuts every week would give you an annual exposure of 0.27 mSv.

Selenium Poisoning

Brazil nuts contain large amounts of selenium. Eating 50 Brazil nuts would result in ingesting 5,000 mcg of selenium. This can lead to toxicity and a condition known as selenosis. This can lead to kidney failure and heart attack.

Adults shouldn’t have more than 400 mcg of selenium a day in their diet.

If you already take selenium supplements it might be a good idea to avoid Brazil nuts.


It’s not all bad news. Brazil nuts contain a range of nutrients that are great for our overall health.

As well as selenium, Brazil nuts also contain good amounts of Vitamin B1, Vitamin B6, Vitamin E, Calcium, Copper, Magnesium, Manganese, Phosphorous, Thiamine, and Zinc. They also contain healthy fats.

As you can see, there are good reasons to eat Brazil nuts.

Health Benefits

  • Eating Brazil nuts can support thyroid function and also help improve the condition of people that have thyroid disorders.
  • The healthy fats in Brazil nuts can help keep your heart healthy.
  • Brazil nuts can help reduce inflammation.
  • Brazil nuts contain ellagic acid, a type of polyphenol. This is said to be good for your brain.
  • The Vitamin E in Brazil nuts can help improve the condition of your skin.
  • Brazil nuts also contain calcium, copper, potassium, and magnesium. These are known to help keep your bones strong.

To eat or not to eat?

I eat Brazil nuts but have a maximum of 3 per day. I don’t eat them every day. Eating Brazil nuts in small amounts can help keep you healthy.

Eating too many can have the opposite effect and cause health problems.