Q. My wife is always telling me not to eat so many Brazil nuts. The last 10 days I have eaten more than usual, up to six a day. I probably ate at least 40 nuts. I estimate that batch contained up to 6 mg of selenium, which is way too much.
I have noticed a metallic taste in my mouth. That’s a known symptom of selenium toxicity, so I am going to stop for a while and not OD in the future!

A. Your wife is right about not pigging out on Brazil nuts. Brazil nuts are high in selenium and an ounce (roughly half a dozen) provides 800 micrograms. That’s about double the US recommended tolerable upper limit. Overindulging regularly could lead to selenium toxicity. Symptoms may include a metallic taste, garlic odor on the breath, hair loss, brittle nails, fatigue, nausea, rash, diarrhea, runny nose, cough and nerve pain. Selenium-containing supplements are another potential source of this mineral.

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  1. cpmt
    Reply

    Chilbob… what are you talking about? I don’t understand your comment (sorry I must be dumb today or brain fog). Please explain

  2. Chilibob
    Reply

    Some people get freaked out about possible ingestion of radiation. Most people know bananas contain the potassium isotope (naturally occurring). What they don’t know is that brazil nuts contain 5 times the level of bananas. The element in the spotlight here is Radium. Look it up…

  3. M
    Reply

    Ooooops just ate about 15 :( they were big too!

  4. Mara
    Reply

    Hmm interesting. Confession time! I went to the market on an empty stomach and bought 50 grams of Brazil nuts, usually I have 2 a day but not today. Over the course of 3 hours whilst running around doing chores and what not I consumed this whole 50 gram bag. Oh my. Now what?

  5. may
    Reply

    I’ve read (or heard) that macadamia nuts also are a good source of selenium but not as much selenium as contained in Brazil nuts.

  6. cpmt
    Reply

    I read in a government website the you should not eat more than 2 or 3 a day.

  7. Kay
    Reply

    Great information. I just bought a big bag of brazil nuts from Trader Joe’s and have been having 4 or 5 a day.

  8. NDF
    Reply

    The NIH only lists brazil nuts as a source that is extremely high in selenium. It is a source that is over 30 times higher than the next listed source, in that 1 oz gives nearly ten times higher levels than 3 oz of tuna, the next most concentrated source.

  9. Noah T.
    Reply

    I am not an expert and constantly on the heels of Joe and Terry. From what I remember brazil nuts are the only one.

  10. Deon
    Reply

    What about those of us who are “nuts” about other nut species too? Is the selenium a problem that is restricted to Brazil nuts?

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