Q. A few years ago I read that selenium was good for everyone and that Brazil nuts were high in selenium. Since I love Brazil nuts, I bought them regularly and ate about three a day. After a few months I began suffering severe leg cramps that woke me from a sound sleep every night. They lasted from ten to fifteen minutes with sharp pain no matter what I tried.

I had no idea what was causing them, so I decided to eliminate foods one by one from my regular diet. When I eliminated Brazil nuts, the cramps didn't occur. I experimented with them several times. Whenever I eliminated them, the leg cramps went away and when I ate even one, the cramps returned.

I'm not allergic to other kinds of nuts. Walnuts, pecans, almonds and cashews don't bother me. Is this reaction commonly known or just peculiar to me?

A. We have not heard of muscle cramps as a reaction to Brazil nuts. At first, we suspected that your regular Brazil nut consumption might have resulted in selenium toxicity. A half-dozen nuts have more than 500 micrograms of this mineral, above the tolerable daily limit of approximately 400 micrograms.

Symptoms of selenium overdose include hair loss, brittle nails, fatigue, rash, digestive upset, irritability and garlic odor on the breath. Since muscle cramps have not been previously reported as symptoms of excess selenium, we imagine this reaction is particular to you.

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  1. John D
    United States

    I have been eating many nuts as between meal snacks daily for years, mostly raw almonds. I added Brazil nuts a couple of months ago and started having leg (shin) and feet cramps. I stopped the Brazil nuts and the cramps are gone. I do have brittle nails with ridges and cracks and wondering if that is related to raw almonds.

  2. maril m
    United States

    I was having leg cramps at night as well. I eliminated almonds and almond milk and the cramps disappeared! Wish I had thought of this 2 years ago! I could have saved many Dr. visits and $. I ‘m just happy I can get some sleep!!

  3. Thinx2DamnMuch

    Simple rule for me regarding eating nuts (basically any kind):
    1) Eat nuts = Leg & stomach cramps will occur the night thereafter. Thus, I eat limited amounts and only a few times per month. I choose wisely, knowing the results will most likely happen.
    2) Do not eat nuts = No cramps.
    Consistent results over years of testing.
    Hope it helps.

  4. Abigail

    Thank you to all of you who contributed to these comments. I had similar problems years ago when I was using a vegetarian protein mix. Recently I have had night time leg cramps. I am going to check all the ingredients in the hot bar selections at our Puget Consumers Coop Natural foods store and the other wonderful natural foods that are packaged. Breads, breadings, cookies and even salads may contain nuts or nut flours.

  5. Mark B

    I’ve been doing a version of the JJ Virgin diet for months. If you’re unfamiliar with the diet, in a nutshell you eliminate 6 foods from your diet:
    Sugar and artificial sweeteners
    I hadn’t had leg cramps since starting the diet. Last night I re-introduced peanuts. I woke up with horrible leg cramps and I still have a cramp in my left leg after being up for a couple hours. I just have to conclude that the peanuts are the cause. If I’ve done the math correctly, there are 577 mcg of selenium in a 1 oz portion of brazil nuts versus 5 mcg in the same amount of peanuts. Still, I’m going with selenium in the peanuts as the culprit. I’m just glad I didn’t have brazil nuts instead!!

  6. Dee

    I purchased a container of raw almonds have been eating all week, the cramps started two nights ago, I could not figure it out
    Thank you all for posting. I think it must be the raw part, I have been eating almonds in oatmeal for years, no problem till I ate the raw ones.

  7. cj

    I finally put together that I get severe leg cramps after eating cereal before bed. Everything I’ve read says the milk, grain, bananas, and nuts should HELP AVOID leg cramps so I couldn’t figure it out until now. I always eat “banana nut” or “fruit and nut” cereal and now I suspect it is the nuts ! Will try a different kind of cereal without nuts and see what happens. Thank you all – I’ve been fighting with this for years.

  8. SAW

    Wow! I am quite happy I finally found other people who get cramps from nuts! I so want to find out exactly why and the mechanism. It is still wonderful to find out I am not the only one. It is, however, for me PISTACHIO nuts that have me jumping up in the night trying to stop a bad calf cramp or foot cramp.
    I have tested and re-tested. It is a guarantee – If I eat them, I get cramps by morning. I am so used to dealing with it for years. Although it took me years to figure out the correlation. I haven’t actually ever stopped eating the darn things, because I love them too much! But if I eat them in moderation, the cramps are not severe and I practically undo them in my sleep before they get worse.

  9. SRP

    I have been eating 2 brazil nuts a day for 3 months and have been experiencing cramps in my feet and general aches in my toes and back. Having stopped eating them, my symptons have now disappeared.

  10. Olddough

    While eating some party mix I ate a Brazil nut that had a very bad taste. Within a couple of hours I developed diarrhea and chills. For the next 5 or 6 hours I was either sitting on the toilet or hovering over it throwing up. During the first bout of throwing up I experienced severe leg cramps in my right leg. I believe all my problems were from the bad tasting Brazil nut. These nuts were in a batch of mixed nuts from Planters and I probably ate around 5 or 6.

  11. Thinx2DamnMuch

    Brazil nuts got me fo sho. Was soaking overnight and eating like a cup a day sometimes. Severe leg cramps at night!!! This webpage helped me figure out why. Thank you so much!
    Staying healthy is so hard.

  12. Donna G

    Earlier in the year I had bought a bag of trail mix from Sam’s club containing, Pistachios, pecans and walnuts, I noticed I began having the toe and arch cramps the worst then, and then the leg (calf and thigh) cramps followed. I initially seen the report on Brazil nuts, which I bought regularly as well, and I have always been a fan of ALL types of nuts, especially in cookies and breads, and cranberry relish at holidays. I also used to eat peanuts, cashews and sunflower nuts.
    Since I have given up eating ALL forms of nuts my cramps have ended. I hate it because I LOVE all of them! I am also extremely sad to know that for my Grandfathers later years in life he suffered terribly with finger and toe cramps and leg cramps in the evening. I did not find out till after his passing this is what his problem was.
    He used to enjoy handfuls of nuts every night. And loved all sorts of nuts in different variations. I wished I had found out and been able to help him. I don’t believe it is a type of allergy to the nuts, but somehow maybe they contain a mineral or vitamin I am over efficient in. Allergy meds do not help. Thanks to all for the additional information! I will miss the nuts…..

  13. Sally

    I have a problem with walnuts, especially raw ones. Phil above (11-9-2009) says “excruciating pain running down my leg”. I get that with walnuts. I don’t get any stomach or abdominal pain but the muscles from my waist to my knees ache terribly and it feels like bone ache – very deep, with my hips feeling like someone’s hit them with a sledgehammer.
    Dallee above (March 20, 2009) says “unusual hip joint pain” and I can relate to that. The muscles feel like I’ve over-stretched them very badly. It isn’t cramp – it’s more like a pulled muscle feeling with extreme aching. It lasts for several days after eating walnuts. It can be so bad that I can’t sleep. It’s like you’ve run a marathon with no training. No change in position eases it.
    Two paracetamol help to mask it for about half an hour. I used to get exactly the same symptoms if I omitted my one cup of coffee during the day. With coffee, the muscle pain from waist to knee lasted up to three weeks – or until I drank a strong cup of coffee. After experiencing this “withdrawal” symptom five times in my life, I’ve given up caffeine and will never have it again. Thank you all for posting about your symptoms with nuts – it’s nice to be able to confirm that our suspicions about the association is valid.

  14. jg

    To add to the record, I also get leg cramps the night immediately after eating Brazil nuts.

  15. P.L.

    Yesterday evening I ate several Brazil nuts, went to bed and woke in the middle of the night with terrible leg cramps. I used to get this a while ago but I have not eaten Brazil nuts for the same amount of time, now I know the cause thank you.

  16. Donna G.

    I found this site looking for answers as to why my muscle cramps and spasms increase, seemingly after I started eating a nut fruit mix. I have always been a “Nut” lover, Pecans, Almonds, Brazil Nuts, etc. I have also always had horrible cramps in my calves, and back thigh, and the arches of my feet and the big toe.
    I have noticed the last 6 months or better, while unintentional, I haven’t been eating a lot of nuts, and I have not had hardly any cramps, usually just the feet. But, almost two weeks ago, I purchases a bag of an Almond, cranberry, cherry and pistachio mix, and I noticed I have had an increasing amount of painful muscle cramps in my legs and feet. Could this be the culprit?
    After reading about the Brazil nuts it really brings the question to my ear. I have tried eating more mustard, that hasn’t helped and a few years back they started taking Quinine off the shelves as it is suppose to be linked to some heart issues, so… I am going to go “Cold Turkey” on eating nuts and see if they go away. I have never been “Totally” free of nuts, so hopefully this will answer my question. Thanks

  17. SUZI

    I believe all those that have various leg craps and irritable leg syndrome need to look at your vitamin D intake and not solely look and blame brazil nuts.
    I suffered both to the point that I was not sleeping at night at all. Legs were both cramping and kicking around. I did a lot of research and have now increased my vitamin D intake and am still eating brazil nuts. A small amount about three times a week. Also in this I have learned to do leg stretches to the maximum that the muscles burn while stretching to stop the build up of lactic acid which is responsible for irritable leg syndrome. I am no allergic to nuts and I do sleep a hell of a lot better at night now. I do hope this helps.
    Thank you, Suzi

  18. Peter

    I get leg & hand cramps too. I wonder if it is the result of some combination.
    My suspects are walnuts, almonds and caffeine, to which I am sensitive. Does anyone have a parallel list of suspects for muscle cramps & spasms?

  19. Andy

    I get an anaphylactic shock from brazil nuts. This is a potentially fatal allergic reaction. It starts in the mouth within seconds (swelling and horrible taste). It causes vomiting within minutes and cramps in the back for hours afterwards. It only takes a tiny morsel and my accidental intakes have caused me to feel the symptoms first and then scramble for the packet (flap jacks in the last case) to confirm that there was brazil nuts in it. This is how I know for sure it is due to brazils which are otherwise only rarely included in everyday ingredients. It’s not selenium in my case- it’s one or more of the known allergens in brazils.
    The interesting thing though, is that I have really bad restless leg at night but it’s restless back too and it emanates from the specific point in my back where the brazil nut cramp got me every time. So I think there was permanent (though mild) damage to the nerves, due to being flooded with immune cells, resulting in permanent restless back.
    It would be interesting to know if there’s anyone else with similar brazil allergy problems. I know it’s fairly rare though.

  20. Debbie

    I found this page because I was wondering if the HORRIBLE leg cramps I had last night could have had anything to do with the Brazil nuts I’ve been eating. I knew that Selenium toxicity could be an issue, but I’d never heard of leg cramps being part of it. Maybe we’re building an anecdotal base for further testing? Guess I better stop eating the Brazil nuts. Darn. I really like them!

  21. Phil

    My completely empirical evidence is that I ate a packet of Brazil nuts last night (200g). Overnight and this morning I have excruciating pain running down my leg. I haven’t done anything strenuous in the last couple of days, the nuts seems like the most likely cause..it may be complete coincidence but I for one am going easy on them from now on.

  22. Deanna

    Selenium has a narrow margin of safety. A normal diet contains more than enough selenium. A few Micrograms too much will send you over the edge. I suggest everyone get a test for selenium levels. If you test high, call the FDA, even if you don’t eat Brazil nuts.
    What state and county your food is grown in has everything to do with how much selenium is in your diet. Be aware that corn grown in Ohio will be selenium deficient and corn grown in south Dakota will be high, maybe too high. High protein grains, such as soybeans, can be extremely high as selenium binds to the protein in the seed. Grain is a seed the same as the nut from a tree.

  23. June

    My husband just experienced his second case of “food Poisoning” that consisted of the runs, sore gut, high temp., dehydration, and fast pulse. It’s 12 hours of worrisome conditions. The doctors called it food poisoning, but now that he remembers there being bad tasting brazil nuts I now wonder if it was the brazil nuts, or maybe too many of them? Any suggestions?

  24. Guy

    Amazing. I have discovered it is the intake of nuts that has been associated with the leg cramps but hadn’t identified a specific culprit. I shall be excluding the Brazil nuts. Good experimenting!

  25. Beau

    Thanks for the good info. I’ve been chowing down on Brazil nuts and my symptoms fit what has been an “overload” of these nuts.

  26. Rosemary J

    After reading the info on brazil nuts I stopped eating them and my leg cramps that woke me up at night stopped. I continue to eat almonds, pecans, walnuts, cashews, pistachios and peanuts.
    I read you column in our local paper every week and have learned many things from it.
    Thanks and keep going!

  27. Connie K.

    My husband has leg cramps. The doctor did blood test on him and found he has high iron. He has to have blood test done and if it shows high in iron then he has to have blood taken out by an IV. The doctor said one of his parents probably had and didn’t know it.

  28. abigail

    Some years ago I repeatedly experienced knee pain after eating sauce made with a vegetarian powdered mix that contained Brazil nuts.

  29. cm

    I do have leg cramps and pain in my legs, sometimes both. The doctor could not find anything wrong. Bone scan and all. I did not have bone density test, should have that. What other foods have selenium in them, maybe I am eating that in other foods? Just wondering, I will watch for that ingredient in other foods.

  30. Dallee

    Thanks for writing up this question!
    For the last week, I started having an unusual hip joint pain — after about 2 weeks of eating more than my typical limit of 2 daily Brazil nuts.
    Definitely going to cut back and see if the pain goes away.

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