/ Food & Drink

Complaints help solve ‘pine mouth’ mystery

Pine nuts

There’s been a mystery afoot with pine nuts. A bitter aftertaste has affected so many that it’s earned the name ‘pine mouth’. Supermarkets didn’t believe us, but with your help we’ve got to the bottom of it.

Complaining is a big part of British culture. Sometimes we even have a good reason to go with it.

So it was slightly surprising when we looked into ‘pine mouth’ earlier this year to hear that so little was being done about an issue that was affecting so many people.

Bitter aftertaste due to unscrupulous producers

Pine mouth is a bitter, metallic aftertaste caused by the consumption of pine nuts, and can in some cases lead to nausea and stomach problems.

We first heard about pine mouth through one of our members, but after our story in August’s Which? Magazine we received literally hundreds of letters and e-mails about this problem.

But when we started researching the causes we found a lot of speculation and little in the way of facts. It took correspondence with the European Commission (EC) to get to the bottom of the problem – namely that an inedible type of pine nut from China had entered the food chain following a pine nut shortages.

Following intervention by the Chinese Chamber of Commerce, the Chinese authorities have endeavoured to stop this practice, but the EC couldn’t guarantee that there wouldn’t be further incidences.

Your pine mouth stories can help

Some issues are too big to be ignored, but while wholly unpleasant, pine mouth is thankfully not life-threatening. It does provide a cautionary tale though. When we spoke to supermarkets stocking the offending pine nuts and also the Food Standards Agency (FSA), we were repeatedly told that they’d only had a few complaints, and hadn’t deemed the issue serious enough.

Any issue relating to food safety should be brought to the attention of the FSA, local Trading Standards officers, and ourselves. This can take the form of a letter or a phone call, but don’t underestimate the power of the nag.

So with your help we can get something done. If you’ve fallen foul of pine mouth don’t just tell us about it below, email toxicology@foodstandards.gsi.gov.uk with details of the pine nuts and the length of time you suffered the bitter taste to get your case recorded.

Craig Rushforth says:
22 March 2011

I am currently suffering with this problem for the first time, even though I have been eating pine nuts for years. My partner, who ate as many of the pine nuts as I did has had no problem.

I had never heard of pine mouth until I googled my symptoms, but as a dentist I have found the internet searches very useful – there have apparently been cases of people having unnecessary dental treatment to try to cure what is probably Pine Nut Syndrome. I have alerted my professional colleagues through a national internet forum.

My pine nuts were bought in Waitrose and yes, they were from China. To their credit Waitrose offered me double what I had paid for them as a refund and promised to look into the problem and keep me informed. I wonder if they will?

I will avoid certainly Chinese pine nuts in future! Trouble is it seems like all supermarket pine nuts are from China. Anyone know of a source of Italian pine nuts?

H.Salter says:
25 March 2011

I have never had any problem with pine nuts until a few days ago.

I used a quantity of Salad Sprinkle from a Neal’s Yard wholefood packet ( “a specially blended mix of hulled pumpkin seeds, pine kernels and hulled sunflower seeds”) bought from Holland and Barrett and with a best before date of July 2011, incorporating the seeds into a batch of flapjack type bars. Since eating some of the flapjack I have had a continuous bitter and disgusting taste in my mouth and at one stage my tongue had a yellow coating. First thing in the morning the taste is not so bad, but after eating breakfast it’s back again in full force. I had read elsewhere that it can last up to two weeks. So far I think I am on about day 4. I’m relieved to see there are probably no sinister effects, but the experience is unexpected and unpleasant.

Nowhere on the Neal’s Yard packet does it state country of origin, but ‘This product has been developed and packaged by NBTY Europe’. [Burton Upon Trent DE14 2WP] ‘Our world class facility allows us to control exactly what goes into each bag. It is our assurance that you are getting the highest quality product’ and so on and so on….. The fact that this information appears to be repeated in Dutch on the other side of the packet reminds me of reading on another site that someone in Holland began research on this problem sometime last year.

Janet says:
27 March 2011

I purchased a 300g pack of Chinese pine nuts from Tesco about a year ago and ate some at that time with no side effects. I sealed the bag up and used about a tablespoon of the nuts on Thursday (24/3/11) although I will admit that I disregarded the best before date of November 2010 thinking this would not be of any harm.

How wrong I was. From Saturday morning (26/3/11) I have had the most bitter taste in my mouth, which seems to be reactivated every time I eat or drink anything. Today I started researching this on the internet and for the first time found out about Pine Mouth Syndrome. Although I am now somewhat relieved to know what my problem is, I am also very angry that retailers in this country seem to have continued selling this product after they were first told about potential issues.

For your reference the batch number on the packet is L0048A9201. I wish you every success in finding a resolution to this problem and a way to prevent these inedible pine nuts from getting into our food chain.

Meanwhile I am off to try some ginger tea as one of the sites I found suggested this can help to alleviate the bitter taste in my mouth.

LauraD says:
28 March 2011

I have never had problems after eating pine nuts before now, however, I bought Tesco pine nuts last week and ate a few handfuls on Thursday. On Saturday I had an awful bitter taste in the back of my mouth when I drunk a glass of Rose and again when I ate breakfast on Sunday and it’s still happening (Monday) when I eat or drink.

Caroline J says:
28 March 2011

I don’t normally eat pine nuts except in pesto but I has some in a meal at a restaurant on Thursday and by Saturday food was starting to taste bitter. I didn’t think much of it but all day Sunday and today I’ve had a really bitter metallic taste in my mouth. Like most people, thought it was a sign a really serious illness but then found the stories about pine nuts on the internet and knew that’s exactly what it was. It’s a real pain because my natural instinct to take the taste away is to have a drink but that actually makes it worse. It’s not the most awful thing in the world but it’s just irritating. It’s fascinating that something so small could cause this for so many people- I’d be interested to hear the science behind why it happens. I do think the supermarkets need to take it seriously though because even though it doesn’t seem harmful, it shouldn’t be acceptable to sell food that causes discomfort.

J Jeffries says:
28 March 2011

Just received this from TESCO,

Thank you for your email addressed to my colleague, Yvonne Edmonds. Yvonne is currently away from the office and I have been asked to contact you in her absence. Upon receipt of your email, we contacted the Technologist responsible for this product in order to gain a full understanding of this problem and the relevance of the country of origin. We were also keen to establish what measures are currently being taken to reduce the possibility of this happening. As you are aware there has been a fair amount of press about Pine Mouth over recent months. It appears to be a recognised side affect affecting a small number of people who are susceptible to this issue. Due to the wide press and FSA interest, there has been extensive, yet inconclusive, research conducted into possible causes. We are protecting our customers by making sure our Pine Nut suppliers adhere to the International Nut and Dried Fruit Council Foundation guidelines and are only buying from the suppliers on the recommended ccnfa list (China Chamber of Commerce for Imp & Exp of Foodstuffs, Native Produce and Animal By|Products ) and have specified that we can only use “Pinus Koraiensis” and Pinus Sibirica. Our current principal suppliers are based in the heart of Jilin province and only sources raw material from Jilin / Heilongjiang provinces. Our suppliers test all pine nuts on intake against specification which includes taste testing and size checks (an important distinguishing factor of variety) This is carried out by a cross functional panel of staff testing against a retained good sample and the test sample. This limits the risk of getting any bitter tastes due to off-grades from other varieties. Given that there are no definitive guidelines regarding testing protocols or even if the species can be separated by analysis, our suppliers will ******** their intake controls when more information is available. As highlighted above, the market in general tends to use Pine Nuts from either China or Pakistan. The Mediterranean pine nuts are more elongated in shape and much softer. Spain and Turkey are the biggest Mediterranean producers, but unfortunately not much is exported from these countries. Our Technical Department has set down some tight quality, chemical, microbiological and physical parameters that the products have to pass. All paperwork for incoming materials and test results have been reviewed for these Pine Nuts going back to August 2009. The incoming materials analysis completed falls within our specified targets for Physical, Chemical and Microbiological targets. These analyses include Peroxide Values / FFA / Moisture and Aflatoxins. Several production samples have also been sampled but there hasn’t been any issues with metallic taint. However, it is quite difficult to test this since the flavour generally develops after a period of time from consumption. While the causes of Pine Mouth are uncertain and effects are sporadic, it is very difficult to eliminate completely. However I can assure you that there is no safety risk in consuming Pine Nuts and that we are doing everything we can to ensure that the products that we produce are of the highest possible quality.
I do hope that my response has gone some way to explain our position regarding this matter and would like to thank you once again for taking the time and trouble to contact our Chief Executive. Kind Regards
Nick Johnson
Customer Service Executive

J Jeffries says:
28 March 2011

The above reply, while lengthy does not even include an apology for the weel of absolute distress we have just been through, and laughably doesn’t even offer a refund for the pack of bad nuts we bought.
At least we now all know that TEACO nust are all ok because they are so very well tested?????? Hmmmm not too sure about that given that even this week others are detailing their problems with the very same product.

Maybe not enough of the complaints are getting to the very top of the organisation. I wrote to the CEO directly.

Craig Rushforth says:
29 March 2011

An afternote to my earlier post – I have discovered that Waitrose stock Italian pine nuts in the Wholesome range. Used some to make pesto at the weekend and absolutely no ill effects.


Janet says:
29 March 2011

Further to my post on 27th March, I purchased some Medicinal Charcoal tablets (made by J L Bragg’s) from my local chemist for £3.45 yesterday as I had read on a website that charcoal could alleviate the symptoms of pine nut syndrome.

I have been sucking/chewing two tablets after each meal and after just 24 hours I can report that the bitter taste in my mouth is now negligible. The charcoal tablets have no real taste although they have a very strange crunchy texture! However if anyone out there is still suffering they may be worth trying.

When in Sainsburys this evening I checked their pine nuts, toasted and natural. Both are packaged in Italy but are the produce of China – beware!

Alison says:
1 April 2011

I also found out about Pine Mouth by googling ‘bitter taste’. In my case it was from a large tub of pesto from Costco. As it was slightly past its Use by Date I used it all up on pasta. I wonder how much the date and fact it had already been opened contributed. I read in one article that pine nuts oxidise quickly, particularly the Chinese ones and this is what causes the bitter effects.

My husband was not affected although we probably ate the same amount. Why should it affect some people more than others?

I’ll certainly take note of the Sell by Date in future, as well as where they come from, and never buy large amounts.

Nixer says:
3 April 2011

I’ve had the bitter taste for about 3 days now, and I think I’ve narrowed it down to a Neal’s Yard Salad Sprinkle bought from Holland and Barrett which I started on Tuesday. I also had stomach cramps for a couple of days and noticed they got worse around mid morning which was when I would have some salad sprinkle. The pack doesn’t state the origin of the pine nuts but I did notice that they were smaller than pine nuts we have bought in the past.
I’m not pleased about this, the bitter taste is one thing but having stomach pain for several days was quite worrying. I intend to complain to Neal’s Yard and H&B and will e-mail the toxicology link above too.

JOSEPH says:
4 April 2011

This is my 9th week with `pine mouth`, I assume, as I have carried out a barrage of investigations to exclude serious disease, all negative. It started two days after eating pine nuts from `Turkey`, they were smaller than usual. The bitter taste persists, in my case it is not abating. I have tried all remedies to no avail. Activated charcoal is difficult to obtain outside hospital, as that would be the last resort in a desperate situation. Red wine and fish bring out the bitterness in force. Shame on Standards boards and greedy importers.

Blimey, 9 weeks is an incredibly long time! We’ll be posting an updated pine mouth Conversation very soon, so stay tuned. I hope your symptoms disappear soon!

JOSEPH says:
4 April 2011

I have just ordered some charcoal tablets from Bragg`s as suggested above. I had tried Eucarbon with no effect. If I list the investigations I carried out you will be surprised, I even scanned my liver, the only procedure I have not carried out as yet is a gastroscopy as I had one this year. LFTs, tumor markers, ESR and CRP, test for heavy metals, colonic detoxification with Klean Prep[ awful] etc..

Reply from Tesco says:
4 April 2011

I contacted TESCO and got the following reply:

— Start of transcription—

“I was sorry to learn that the Tesco Pine Nuts you bought from us recently had a bitter metallic aftertaste. I can appreciate how unpleasant this must have been for you and I sincerely apologise if it has given you any cause for concern.

This appears to be a natural phenomenon as the Food Standards Agency have also received several reports over the last few months about pine nuts that have caused a similar taste for some people who have eaten them. I can confirm this is not a food safety issue, but the Food Standards Agency is trying to get more information. They have been in contact with the Poisons Centre in Belgium, which has researched this phenomenon. They have investigated this at some length but have been unsuccessful in establishing why this happens. Batches shown to cause the unusual taste and batches giving no effects were compared and no chemical differences to which the bitter taste could definitely be attributed have been found.

The bitter taste usually disappears after a few days but has been reported to last for as long as two weeks. As far as we are aware, no adverse health effects have been associated with these symptoms. We will continue to monitor these reports. However, the current lack of information on why and how this effect occurs is limiting the scope for further investigation.

I hope the above information has alleviated your concerns and gives you some reassurance that we are working hard with our suppliers to resolve this issue.”

— End of transcription—

Apparently something is being done!


H.Salter says:
4 April 2011

I don’t know if this techy thing will work, but hopefully below you’ll see both my response and the email I received from the FSA Toxicology Department this morning.


Dear Darren,

Thank you for this detailed reply. I still have half the quantity of Neals Yard salad sprinkles (a mix of pine nuts, sunflower and pumpkin seeds) which was the cause of my problem, and also the 250g packet they came in. The pine nut content is given as 14%, so in total I consumed about 20g over a two day period, as I think I used around half the packet.

The best before date is still three to four months ahead, and the packet was unopened until I decided to incorporate some of the seeds into a flapjack recipe. I shall post this to you sometime this week together with a copy of this email and the response I got from Holland and Barrett.

My symptoms of aftertaste began within a day of eating the flapjack and lasted about two weeks. Halfway through this period I noticed a white coating on my tongue, and one night I woke up because my breath smelled absolutely putrid. This cleared in a few hours, but for the last two or three days the tongue coating has changed to yellow. The bitter taste began after I ate or drank anything except plain water, and lasted for hours. One day I made a vegetable curry and thought to add a fairly large amount of turmeric as I believe this spice has valuable antiseptic properties, and I found the bitterness was lessened for a while, though I don’t know if this was due to the turmeric content or not. The morning after the putrid breath incident I ate a large quantity of bio yogurt which did seem to help somewhat.

It is not the pine nuts that taste bitter.

The ‘Which’ conversation site today has someone writing that he also suffered stomach cramps, as well as the bitter aftertaste. He bought his pine nuts from the same source as mine, and says he will be contacting your department as well as Holland and Barrett. On the same site someone has just posted that they are in their 9th week of the aftertaste.

The ‘pine mouth syndrome’ is also being experienced in the United States, according to internet blogs.

Adults seem able to cope with the symptoms, however unpleasant, but my concern is the effect these ‘nuts’ may have on any very young children who might be vulnerable to the toxin.

As I said, I shall be posting the actual packaging to you, and you’ll see the BBE is July 11 and that the contents were packed in the U.K. Below the BBE it says 11019 10:55 2 49660, but I don’t know whether this is the batch number? Although it’s indicated that the contents are well within the best before date, I did wonder how long the seeds had been in storage in the country of origin before being processed.

Thank you for responding to my complaint.


=== Reply ====

Thank you for your recent communication on pine nuts.

No long term health effects are anticipated following the resolution of this bitter taste – despite the fact that the exact causative agent or mechanism is at present, unclear. At present it is thought that this phenomenon might be due to the pine nuts exported from China becoming mixed with non-edible species of pine nut. The Chinese authorities are working with suppliers to raise awareness of the issue and minimise the chance of this occurring.

We have received reports that “bitter pine nuts” are commonly consumed in some regions of China with no widespread effects noted. If any further effects are noted relating to the consumption of pine nuts other than those reported already, please contact us again, and speak to your GP or another healthcare professional. We are not aware of anything that can be done to alleviate the bitter taste disturbance in sufferers.

Colleagues in France have recently undertaken a sampling and analysis exercise to see if they are able to shed some light on this phenomenon. Neither they nor the Belgian Authorities who investigated this in 2001 have found a prospective causative agent as there were no obvious differences between pine nuts that had this effect and those that did not. We currently do not intend to carry out a similar analysis exercise, although we have not ruled out other types of investigation, finances permitting.

We are setting up a detailed database of reports to allow us to spot trends and monitor reports and would be grateful if you could respond with details of the pine nuts that you purchased if still available. We understand that it is likely that you no longer have the packaging or many of the details but would be grateful if you could provide us with as many details as you are able to recall.

We are especially interested in the following:

• Batch no and pack size,
• When opened and how long before consumption and details of storage
• Country of origin
• How long you experienced the aftertaste for after ceasing consumption of pine nuts
• Whether the pine nuts were within their best before date or not
• Which, if any, foods made the taste much worse

Thank you very much for your interest and help with this issue.



Higher Scientific Officer
Chemical Risk Assessment Unit
Food Standards Agency

JOSEPH says:
5 April 2011

As you may see from my blog above, this is my 9th week with this bitter taste coming on 2 days after having pine nuts from `Turkey`. The best before was ok, my wife had a short period of the symptoms and mild. Opened and used on the same day. Red wine and fatty fish make it worse[ salmon and tuna]. I have carried out a barrage of tests as stated above+ENT and dental examinations, all normal.

H.Salter says:
4 April 2011

Below is the response I got from Holland and Barrett. They did offer a refund if I telephoned them with my address, but I emailed that. Didn’t want to spend more money on a phone call! Still awaiting refund.

Thank you for taking the time and trouble to contact us regarding Pine Nuts.

I am sorry to learn that you have experienced a reaction to the Pine Nuts.

We go to great lengths to ensure that all the products we sell meet the highest standards for quality and are manufactured with strict adherence to the appropriate good manufacturing practices.

The FSA is aware of the issue that some people experience when these nuts. At the present time it can not be determined why this should happen two people can eat nuts from the same batch and one person experience it and the other person is fine. It does seem to be an individual reaction.

This is something that we are aware of and your comments have been passed to the Technical Service Department for their information.

With regard to the information on the packaging this has also been passed to the relevant department for their information.

If you would like to contact me on 02476215435 to provide your address details I will send out gift vouchers to cover the cost of your product.

Yours sincerely
Lin Pearson
Customer Service Team.
NBTY Europe.
The home of Holland & Barrett

Nixer says:
4 April 2011

I do hope mine doesn’t last 9 weeks – I’m going to Paris at the weekend…How awful for you.

One or two foods that I have found that taste sort of ok are
1) Marmite
2) Garlic – just had a very garlicky potato salad which was ok
3) Oyster sauce

Given 1 and 3 am considering putting salt on everything.

Sweet foods are horrid and the absolute worst I have found is bananas, closely followed by peanut butter.

I’m interested in what’s happening here – is something interfering with the salivary glands or the tongue? I’ve noticed my mouth feels a bit “boggy” even when not eating and it feels as if there’s a sort of “bad air” right in the back of my mouth almost down my throat. I have been cleaning my tongue when I clean my teeth and it helps with the boggy mouth for a while but it comes back. The garlic probably isn’t helping.

Incidentally the pine nuts tasted fine, not rancid at all. I’m mildly curious as to what they will taste like now but have no desire to ever eat a pine nut again. I daresay there’s money in it as an appetite suppressant.

Nixer says:
4 April 2011

Oh I’ve just seen Heather’s reply. I got the same e-mail from Darren at FSA Toxicology this morning. I’ve only had an acknowledgement from H&B, no actual reply yet. I’m waiting until the bitterness goes (fingers crossed) before I reply to FSA as they wanted to know how long it lasts.

My batch was BBE: Jul 11
and under that it says
11019 12:05 2 49702

Bought in Farnham a few weeks ago.

I’m female by the way:)

I’ve discovered that toasted sunflower seeds taste very similar to pine nuts. I found this out because the price of pine nuts went up so much, but for those experiencing pine mouth, it might be a good (and cheaper) alternative!

H.Salter says:
6 April 2011

This morning I received a voucher from Holland and Barrett for £10 after complaining about the effects of pine nuts used from their 250g bag of salad sprinkle. I shall be very careful what I spend it on.

Nixer – sorry about that. I should have said ‘they’! 🙂