The Mystery of Pine Nut Mouth

Yesterday afternoon I noticed a bad taste in the back of my mouth. I chalked it up to post-nasal drip from seasonal allergies and tried to get on with my life. But by this afternoon, the bad taste had crept all the way forward and really set up shop. It colored everything I ate and drank, whether I was having a banana or a cup of coffee, whether I had just brushed my teeth or chewed a stick of gum or gargled with salt water, the bad taste didn't budge.

After I put aside yet another meal only half-eaten, I decided to do a bit of Googling. Among all the web pages suggesting that I might have a brain tumor (really) I noticed a mention of pine nuts. And then I remembered two things: having read about Pine Nut Mouth a few months ago, and having eaten pine nuts (for the first time in years) on Sunday.

How tragic, that such a nice Easter brunch with a friend of the family should result in… this.

Pine Nut Mouth is quite a mystery, albeit a well-documented one. It is a form of very mild poisoning which results in several days - possibly up to several weeks - of a syndrome called metallogeusia, which is the medical term for a lingering bitter, metallic taste. It causes no real harm, which is good, because there is no cure but time.

Pine nut toxicity is tentatively linked to pine nuts imported from China. The nuts have been tested and are free of any chemicals or heavy metal poisoning that researchers know could be toxic. The current theory is that it is caused by spoilage or oxidation of the pine nuts. It may also be something to do with a new species of pine nut being mixed in with the rest.

The reason why it's impossible to chase away the bad taste by eating or drinking something else is that the bad taste is actually happening in your brain, not in your mouth. Whatever substance causes the problem does so by interfering with the nerve impulses from your mouth to your brain. It's a misfire, in other words. But instead of producing a flash of light or sound, like a misfire in a car's engine would, this misfire produces a very bad taste.

Adding to the mystery of Pine Nut Syndrome is that it doesn't affect all people equally, and the CDC has been unable to find any chemical compound that would cause the problem. One batch that produced a lot of complaints came from Costco. In response, Costco sent samples of that batch plus a control that had received no complaints to several highly respected toxicology labs. None of the labs were able to find a difference between them. And the majority of people who had purchased and eaten the "bad" pine nuts showed no symptoms.

The FDA is continuing to examine the mystery of Pine Mouth. According to their website, most of the reports involve a particular species of Chinese pine nuts, and most of the nuts were consumed raw. If you experience a bout of Pine Mouth, you can report it to your state's FDA inspector here.

Photo credit: Flickr/scribbletaylor


Diane's picture


Pine Nuts - The Bitter Truth!  Thank you for posting your commentary - I too had the same experience over the weekend after ingesting pine nuts purchased from Trader Joes.  They were prepared in a recipe that I hadn't used for years.  Also, I took another handful (raw) on Sunday evening.  By Monday evening, within 24-48 hours I sat down to have a steak I had purchased from a local butcher and there was a bitter explosion in my mouth and subsequently after, everything I tasted even cookies turned bitter and metallic.  Needless to say I did not finish the meal. In addition this was accompanied by indigestion, a bit of a sore throat I thought was allergies, tiredness and questions as to what actually was going on eg: what was the source and how was this impacting me systemically.

Like you, by Tuesday I took to the web, after discussing the issue with the butcher to rule out beef. It did not take long to find that pine nut problem was prevalent througout the world and is well documented on the web with history of pine nuts from China, Russia, Korea being the culprits.  Now we can add Vietnam to the list.  Trader Joes is a store that I go to on a regular basis and have trusted for safety for many years, but shame on them for bringing in products that they have had historical problems with and especially with a label that reads origin: Russia, Korea or Vietnam.  What is that?  There is no difinitive country of origin. 

By Tuesday evening I had alerted Trader Joes locally and the proceeded to call the poison control center because I believe this is not about taste buds and bitterness there has to be some correlation to systemic issues of liver and digestive system, otherwise it would be gone within a few days.  The woman at the poison control center informed me that according to recent research it may take up to 3 weeks for the toxins to circulated through the liver and digestive tract.  She then gave me the local number for the FDA, which I have called.  I will be sending in a report.  FDA is already overworked as more commodities are brought in from countries where we have no control over the soil or water quality.  Yes, it is nice to have our palate treated to foods from all over the world yet we are at more and more of a risk as the environment in which we grow our food sources in becomes compromised.  ( I won't even get into radiation issues).

Bitter? YES, I am now going on nearly a week of not even liking the taste of water.  My questions is why do we still import these toxic products?  ( I understand that this is mild poisoning and it takes as little as 40 grams to trigger this response).  I will be sending my post information to the local newspaper and to Trader Joes ( I see Costco had the same issue).  If this has been a problem over the last two to three years and now is spiking again, then why do we still have it on the shelves?  A recall may be in order for FDA test the batches and stop the importation of pine nuts from these countries.

I do not know how my "forced diet" will continue as the my taste nerves are inoperative but I hope this aids others in solving their mystery and get some response to eliminating these products from our shelves.


I agree, I have no idea why they are still selling imported pine nuts! I'm on day 3 and it has definitely waned a little - yesterday was the worst - but I am still a very unhappy camper.

Thanks so much for your report! I hope they do something about this soon!


Diane's picture


I am working on contacting press, have called Trader Joe's with an unsatisfactory response - the will not pull from shelves even though they have gotten some complaints, until FDA steps in on a recall.  There are probably many people who are just wondering what is happening and have not pursued researching, but this is not a trivial matter and goes beyond some idiotic name as "pine mouth".   In the meantime the Telegraph has written this article in the past few days...

you can twitter on their site... I noticed even Dubai chimed in...


OMG from that article!

"Now China has admitted some exporters have been mixing the Pinus koraiensis variety with the cheaper but inedible Pinus armandii.

The latter are deemed "unfit for human consumption" by food safety experts at the European Commission but the lack of long-term harm means regulators have stopped short of a recall or a ban on imports."

Thanks for the nudge, by the way - I phoned the local FDA office and left a report on their message line.


Diane's picture


I am hoping that more people will see this because it is the most recent activity - the last web postings I saw were from November 2010 - so you have done a good thing bringing information up to date. No telling how many people are effected but do not know how to go about getting some answers.  I have experimented with some foods eg: papaya, green cleanse, fresh pineapple for enzymes also a good probiotic daily as I am concerned for liver, bile and digestion.  Of course, everything ends up tasting terrible. Anything lemon seems to help, but of course, not for long.  A metal mouth "aftertaste" is what many going through chemotherapy get, so one can only imagine what is going on here. I will keep trying to reach FDA.  You should also call poison control at the state to report your case.


Anonymous's picture


I, too, got it and it is amazing how colorless the world seems when your tastebuds have been kidnapped by metal!  Someone suggested active charcoal and aloe vera tablets (health food stores) and they worked like a charm.  Within hours I was much better!


Barb's picture


I am beginning to panic about my on-going experience with this relatively unheard of syndrome.  This coming Wednesday will be 8 weeks of messed up taste buds for me! I have no idea why this is lasting so long.  I am able to get some flavors that come through but most meat and all sweets have absolutely no taste.  Though I read on the internet that this could last a couple of weeks I haven't come across any mention of anyone having these symptoms for this length of time.  As a result I did visit my PCP, an ENT physician and an acupuncturist with basically no help from any of them.  I am in excellent health and have had a full range of blood tests done with no negative results.  Most of the time I have a salty taste in my mouth.  There are days when I think I have finally turned the corner only to wake up the next day and discover it's basically the same as before.  Can ANYONE PLEASE help me or at least confirm that they have had a similar experience?!  Will I ever completely get my taste back?  I saw a post about active charcoal & aloe vera tablets helping.  I intend to try that next.  What's very disturbing is that when I told my doctors & acupuncturist that I read about this on the web they pretty much dismissed me.  I even printed out articles for them but I doubt they took the time to read them.



Julie's picture


I have had it 8 weeks also.  Did you ever get over it?  If so how long did it last?


richard and kay taylor's picture

richard and kay...

both my wife and I experienced the same reaction to old trader joe's pine nuts.  we had toasted them, to make them more flavorful.  about two days later we simultaneously experienced bitter metallic flavors in the back of throat and roof of palate.   we both eat new beautiful fresh cherries and to our horror said "these taste terrible"  why would the store sell these!   it has been about two days since this manifest itself, and taste is  really off.   thank you for easing our mines, we could not figure it out, because of the delayed onsite.


Diane 's picture


Here's my update:  Trader Joes now displays the risk on their packaging. The pine nuts are still out there.  I have tasted other pine nuts since the first poisoning incident and have not had a reoccurance of the acute symptoms.  I saved the original package purchased and offered to FDA.  Last updated them a few months ago.  My personal conclusion is that it is more that a metallic mouth disorder... my digestive system has never been the same since.


Sue's picture


We bought pine nuts from Trader Joes to make pesto with the fresh basil in the  garden. And have both had this "pine mouth" bad taste. My husband had it first and worse than me, Mine started a few days later and so far doesn't seem to be as bad. His has lasted for about 3-4 days so far. We were amazed that the pine nuts at Trader Joes were 1/3 the price of those at Whole Foods. Now maybe we know why.


fatboy's picture


Wow. Surely this has got to be the best news for weak-willed dieters in years. I reckon if you can find a way of taking the pleasure out of eating, temporarily and with no other real side effects, it would solve the problem of boredom eating.

If you could sell this as a pill I'd buy it.


grambon's picture


I have had a very salty taste in my mouth for some time now.  Nothing I do helps to get rid of it.  Nothing tastes the way it should  either.  Upon reading some comments on here about pine nuts I see this can be from eating them. No more for me !!!!!   One person says it's been 8 weeks since her taste buds vanished.  How long will it take !!!!   Something should be published about these side effects so a person knows before buying/consuming.


Sue's picture


Ate Alessi pine nuts (from China) 3 days ago and developed bitter taste in mouth 1 day ago- all foods and drinks have a bitter/metallic aftertaste.  Won't ever buy the product again!  Should be banned.  Hope the symptoms go away quickly.


christy's picture


Hello to everyone who had the VERY unfortunate experience of bad pine nuts!  This also happened to me last year at Thanksgiving while eating a salad with Pine Nuts. It only happened to me, and it was very miserable, to say the least.

I researched the toxicity and I believe that I have uncovered the mystery and found the cure. Most pine nuts come from China. To meet our demand, they throw in the nuts from the white pine, which are not regulated. The white pine also provides us with terpintine.

Anyhow, to make a long story short...there is a chemical in the white pine nut that causes our bodies to increase bile production. I believe this is the unfavorable taste in our mouths after eating a tainted nut, especially once we start eating or drinking and our bile production increases naturally as it is.

Here is the cure...Pepcid.  Once I took it after suffering for 6 days, in disappeared within 15 minutes. Good luck, hope it works for you too!



Cristina's picture


I am a lawyer in San Francisco and we are looking for individuals who have experienced an aftertaste or other adverse reactions from eating Pine Nuts from Trader Joe’s. Particularly, we are seeking San Francisco Bay Area folks who can provide us with information about when and where they purchased the pine nuts, the symptoms they experienced, whether they still have the pine nuts, and whether they saw a warning on the package of pine nuts. If you can provide any information, please contact me at


Pine Mouth in Ky's picture

Pine Mouth in Ky

I got pine nut mouth from pine nuts purchased at a local Korean food store.  Two days later pine mouth set in.  But I got rid of my pine mouth by flossing twice and rinsing out my mouth with salt water.


Shirley's picture


I have been trying to figure out what is causing this taste in my mouth.  I've had it for about 1 week.  I saw my dentist this morning because I thought it was from a composite filling they had done in early September.  He could find nothing.  I called my pharmacists and she found nothing with any of my meds I'm taking.  Next step, start researching this on-line and I found this site here.

My pine nuts came from Costco and yes they are from China.

Everything I eat has a bitter, metal, tin taste and as much as I love wine with my dinner I have stopped drinking that as well due to the bad taste of the wine.  It's terrible what this has done to my taste buds.

I took the advice of one of the posters and just took an activated charocoal tablet hoping this will help. 

I simply can't imagine going for 8 weeks like this.

Thanks to everyone that has posted, and yes something needs to be done about imports from China that are contaminated.






Ashley's picture


Last night I made some toast with pesto on it that I purchased from Costco. By bedtime I had an awful bitter taste in the back of my mouth that didn't go away even after thoroughly brushing my teeth and using mouthwash. I thought it would just go away and went to bed. Today when I woke up the taste is even worse! I've had coffee, gum, ate lunch, but the bitter taste just won't go away.

I'm sure the pine nuts used in Costco's Kirkland brand pesto come from the same place their plain pine nuts come from so could the pesto be the culprit? I will definitely be throwing it out when I get home and hope my case of "pine mouth" doesn't last for weeks upon weeks!

Haven't tried any of the recommended fixes yet... to the poster who recommended Pepcid, there are other causes of bitter/metallic taste in mouth that include acid reflux and digestive problems. Is it possible that you were experiencing something other than pine mouth? If this horrible taste lasts for another week I'm sure I'll be willing to try pepcid regardless!

Also, I've never heard of aloe vera pills. Would one have to go to a specialty store to find them?


Christy's picture


Hi Ashley,

I am more than positive it came from the nuts. I am a healthy young woman who does not experience acid reflux, or any kind of stomach issues.

 The reason I tried Pepcid is because Pine Nuts, especially certain ones from China contain pinolenic acid. When ingested, this acid triggers cholecystokinin, which causes the release of enzymes and bile from the pancreas. Therefore, I assumed the "bitter" taste in the back of my mouth, or when I drank/ate something was being caused by the over production of bile from the high pinolenic acid of the nuts. Pepcid worked for me and I was just passing on my remedy because I know how miserable it was.

Even though Pepcid did work, I have still not eaten pine nuts since then!


Mitch's picture


First mystery experience is as all of these posts, but about two++ years ago when there was very little posted info on this subject. Very scary at that time as the taste was like a "bitter green potato skin, or an un-roasted walnut, chestnut etc." I had been taught growing up that this was from a form of naturally occurring strychnine poison when potatoes are exposed to the sun. This is a bitter taste you never forget if encountered that occurs naturally in many plants. It's generally an immediate warning that it's not safe to eat, at least until cooked. The difference is that this pine mouth syndrome doesn't show up for a day or two, lasts from 4-6 weeks, and fades away slowly over time.

After figuring out the cause and realizing that we would not "die a slow and bitter death" we noticed the nuts we had used in the pesto did not look like the large nice white ones we had bought in the past. They were about 1/2 the size and darker at the end of the nut. Costco buyers seemed to know about it then, and had already removed their product. That's why we had bought a different brand from another store, as Costco was not carrying them anymore at that time. When they brought them back a couple years later (spring/2011) we figured they would be safe. Costco is usually very careful and we figured they wouldn't bring them back unless they were ok.

WRONG!! We ruined another batch of pesto and these are Costco nuts. To their credit they refunded the $$$ for the nuts (they're the best at backing up their products) and I'm sure they did not know there is still a problem.

Here's what I've learned,

The Costco nuts look like the nice big nuts of the past, but when you look closer we notice that there are a lot of the smaller size, darker ended nuts in the mix as well. We believe these are the culprit. I expect their china supplier has figured out that the diluted product may squeak by if it's not as concentrated so their mixing them in with the good nuts for the $$$.

The strength of the reaction and length of time affected seems to have a direct correlation to the quantity of the bad nuts consumed. This 2nd round of "pine mouth" was not as bad or as long as the first as we were carefull to test first with small quantities and wait 24-48 hours before going "Whole Hog".



Joan Warnecke's picture

Joan Warnecke

Thank you so much for all the info you have provided. I had pine nuts (purchased from Sam's Club) Saturday night and by Sunday night I felt as though I had swallowed a giant bitter pill. I had gone on the internet to find the origin of the pine nuts and that is when I came accross Pine month. I certainly feel much better knowing that I'm not going crazy and/or none of my medications are causeing this, and if they made a diet pill using pine nuts, I'd rather be fat.


Frances Tipton's picture

Frances Tipton

I have had this awful taste for about five weeks. Have been treated with pills for fungicidal and gastric problems to no avail. Was about to be sent to hospital for 'tests'. Then I say by chance an article on pine nuts and it fits exactly with my eating them just before the onset of the taste. I do feel poisoned and cannot believe it is just 'a bad taste' but hope that that at least goes off eventually. Nuts bought from a 'health shop' in London, UK


Teresa Sanders's picture

Teresa Sanders

I, like most everyone, went to the web after becoming ill and feeling like I had chewed bile laced aluminum. I have a recurring headache too. Yup, got my pine nuts from Trader Joe's. It's been a week now I still feel sick and still have the bitter metallic taste.
I publish a weekly newspaper and if I live to next week there will be an article. I'm also sending this information to Congressman Mike Thompson's office (1st Dst. California). I suggest everyone do the same. If not Thompson, send it to your area representative . We are being poisoned and no one seems to know definitively from what.