Q. I was taken aback by your remarks about limiting the number of Brazil nuts eaten. Many years ago when I was growing up, my parents bought nuts at Christmastime. Brazil nuts were my favorites and I ate tons of them. I continued the tradition as an adult. I ate lots myself and gave them to my children.
I have not seen Brazil nuts much recently and I seldom eat them. But what did I do to my health and my children’s with all these nuts?

A. Any health problems that might arise as a result of excess selenium would fade after you were no longer eating Brazil nuts or other selenium-rich foods. Selenium is a little bit like Goldilocks’ porridge: you need enough, but not too much.

The most common symptoms of selenium poisoning are seen in hair and nails. They can become quite brittle and fall out. Other problems you might have noted around Christmastime could have included rash, stomach upset, irritability or fatigue.

The tolerable upper limit of selenium is 400 micrograms a day for adults and less for children. An ounce of Brazil nuts, about half a dozen, may contain as much as 800 micrograms of selenium, so it makes sense not to gorge on too many too often.

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  1. PM
    Reply

    Hi everyone,
    There is something else to consider with Brazil nuts, and that is that they are particularly prone to getting moldy and many people have mold allergies. I can often taste this in them. Germany has severely restricted the sale of Brazil nuts for this reason.
    What a shame…

  2. ljc
    Reply

    I have been eating 3 Brazil Nuts a day for quite a few months now. (Solely for the health benefits of selenium).
    A few weeks ago, I noticed that my nails have become very brittle (peeling) and notice hair falling out.
    I have also been waking up with a bad taste in my mouth.
    I am so grateful to has read the article and all the comments. I am definitely stopping the consumption of the Brazil Nuts and will find another source of selenium. Thanks!!

  3. Elley
    Reply

    My thyroid readings fluctuate and so do my moods/memory etc. Doctor says until I have 3 consec high reading he will not do anything.
    I read that 1-2 Brazil nuts would help and they do help but only to a point.
    I am going to docs for Blood tests and wondered how long before the Blood tests I should stop eating Brazil nuts to give a clear reading.

  4. flomaloma
    Reply

    hace aproximadamenten tres meses consumi una generosa cantidad de nueces del brasil. En ese momento no sabia que producian alergias sin embargo hace 15 dias me salio un brote en la espalda y axilas. es bastante doloroso. parece que es herpes ¡sera que esta ingesta de nueces me produjo este molesto brote?
    agradezco me informen algo al respecto.
    People’s Pharmacy respuesta: Creemos que las nueces del brasil probablemente no tienen responsibilidad. (tiempo que paso entre el consumo y el brote) Si es herpes, una medicina antiviral tal vez ayuda al alivio

  5. EE
    Reply

    Had an episode at 3 years old and one when 12 years old (“so long has passed it can’t hurt me again… ouch!”). I had only eaten a small bite both times and both times my parents rushed me to the hospital. From then on, always carried with me a cortisone pill and now an epi-pen. AFAIK I’m only allergic to Brazil nuts, I can eat all the “normal” nuts (never tried macadamia or pecan though, not common in my region) as long as I crack them out of their shell.
    Doctors told me the brazil nut allergy works for accumulation because, for some reason, my body cannot process some of the elements in it. There is an allergen database online showing that brazil nuts contain two special allergen not contained in anything else (according to the database) and I think that this might be the reason why I can safely eat other nuts. Careful! it could work differently if you are allergic to other nuts too.
    Hope this helps, only it’s a stress to be always on guard, a couple of weeks ago there were Brazil nuts in a salad in the cafe’ I was about to eat in, needless to say I changed my lunch plan!

  6. LL
    Reply

    It seems as though nobody got the memo; eat ONLY 1-2 Brazil nuts a day. That dosage is the amount of selium you need for your thyroid hormone to function normally. Either 1 Brazil nut or approximately 6 cups of crimini mushrooms.

  7. Lorrie
    Reply

    Lately I have been snacking on brazils for their selenium due to a suspected under active thyroid. Three days ago I got itchy spots starting in the back of my head. Soon after large itchy hives travelled down over my shoulders, chest, torso and the next day my arms, backside and legs.
    I am allergic to penicillin mould so thought I had accidentally ingested some in my food. After finding this site I am now wondering if it was the nuts and as someone suggested “mycotoxicity”. At last this is all making sense so thanks for your help. I also will be avoiding them in the future.

  8. Theresa
    Reply

    I had a simular reaction to eating some brazil nuts a few weeks ago. I am hypothyroid and the brazil nuts created what felt like hyperthyroid symptoms. I woke up after three hours of sleep with a racing heart and I was very hot and could not sleep. I had some beta blocker medication which I was prescribed years ago when I was suffering from hyperthyroidism, I took one dose and felt a bit better. I remembered reading recently that selenium deficiency could cause someone to become hypothyroid so I began taking selenium supplements and I became hyperthyroid as a result. Selenium is needed to convert T4 into active T3 hormone so if a person doesn’t have enough selenium they will become hypothyroid.
    I have been experimenting with the amount of selenium and brazil nuts I am consuming and I have been able to cut back on my Armour thyroid medication by 75%. I have been taking 800 mcg of selenium a day and consuming about 8 to 10 brazil nuts as well for the last 6 days and I have been feeling much better. I have contacted my doctor and he is planning to run thyroid tests on me next week to see if my thyroid is really working on less medication while consuming the selenium supplements. As of today it appears that I can cut my thyroid medication by possibly 87% or more.
    I would guess that anyone having the same experience as your mom and I would most likely be suffering from hypothyroidism.
    People’s Pharmacy response: We emphasize that this type of experiment should be done in collaboration with your doctor. 800 micrograms of selenium a day could be toxic.

  9. Sick from Brazil Nuts
    Reply

    I bought a bag also and I was up to eating between 6-8 a day. I noticed that I was getting so sick during the day that I had to stop what I was doing to rest. I became SEVERELY sick, sweating, legs numb, face hot, shaking, unable to restore proper breathing pattern, metallic taste in mouth and a bad headache. I will NEVER eat these things again. The hospital said that it was not an allergic reaction. The doctor said that my body was responding to an overdose of selenium! I think there should be a warning label attached to these nuts as a precautionary measure.

  10. lee
    Reply

    my mom had brizilian nuts last night and today she woke up sweating non stop, being sick & shaking why is this?

  11. Matt
    Reply

    I’ve been allergic to Brazil nuts for as long as I can remember.
    First exposure was around the age of 4 or 5. The only thing I remember was an itchy mouth, tongue, & throat, and my lips and tongue swelling.
    The second time it happened was when I ate a small bite of some easter candy when I was 11 or so. If I remember correctly the oral reaction (itching and swelling) wasn’t as severe, but it did cause me to vomit terribly a short time later. I think the initial attack was slightly weaker because of the small amount of the nut which I consumed.
    The third reaction was around the age of 17/18. I grabbed a handful of bridge mix and included in the mix is, of course, chocolate covered brazil nuts. For some reason the reaction always waits until just after I swallow before it kicks in, then it rears it’s head. This time was much worse than ever- Itchy tongue, cheeks, and lips. Swelling tongue and constricting throat, difficulty breathing and hives. My mom promptly drove me to the ER. Two magic phrases that get you immediate treatment in an emergency room are 1) heart attack 2) anaphylaxis (or I ting om habbing allegy am I cand breev) as long as you can convey that your throat is constricting, they’ll pay attention.
    There I received epinephrine and benadryl and I learned about the “second wave” attack, which happens after you survive the initial anaphylactic blast. Second wave consists of your stomach contents violently being projected across the room. It doesn’t last long, but it’s not fun.
    I’m glad I found this forum, it reminded me that i need to get a new epi-pen – if you discover you have an allergy, especially a nut allergy- don’t play around, they typically get heavier, faster and more deadly with every exposure.

  12. B
    Reply

    I was eating about 4-5 handfuls a day for 3-4 days before I got really sick and stopped eating them. I can’t even stand the smell of them now and I threw them all out. Now I’ve had constant diarrhea for the last 4 days and can only eat a little bit of food at a time because it’s hard to keep down. How long will this last? It doesn’t seem to be getting better :(

  13. Amanda N.
    Reply

    I bought a bag of brazil nuts last week and my son and I were eating a small handful each most days. After a couple of days, I started to get very distressing symptoms (sensation of brain expansion and swollen throat, primarily), but hadn’t made the connection until today when I hadn’t eaten anything else and thought to look into it online. My son has been complaining of itchy spots (little red patches, if you look hard) all over for a few days, and no other explanation is evident. I shall dispose of the remaining nuts and see how his skin goes…. I certainly won’t ever be tempted to try another one!

  14. donna z.
    Reply

    Hi,
    This is strange. I remember eating Brazil nuts when I was young but when I go older I never knew I was allergic to nuts at all. I do remember getting a slight rash when I was young but that was it when I got older and in my 40’s I had a trip to the hospital which almost I died from peanut sauce on some ribs at work. My throat closed up and cpr had to me done on me and I remember is waking up in the hospital the next day. The smell of planters peanuts drives my senses crazy. I cannot tolerate it or peanut butter.

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