Who would have thought the simple (and extremely tasty) pine nut could cause so much grief; so much suffering; so much dieting. If you’re a fan of these little kernels, there is something you should know about them: they’re PURE EVIL!

Okay, that’s not entirely fair. Not ALL pine nuts are evil. My research has indicated that it is only pine nuts imported from China that are the cause of my suffering, and the suffering of many others.

Last Thursday night I was preparing dinner for myself and a friend, which we possibly wouldn’t be eating for another hour or so. I was hungry and needed a quick snack to stop me from eating all the dinner ingredients. So I reached into the cupboard and grabbed myself a handful of pine nuts. Mmm tasty. They were from the same box of pine nuts I had used on my carpaccio, rocket and raspberry salad a few weeks before, so how could I know the effects that would soon take hold…

On Saturday morning we got up late; it was almost noon, so instead of breakfast I decided to skip straight on to lunch and eat some leftover leek and potato soup that was in the fridge from earlier in the week. At first taste I thought, “Agh, I think this is past it’s used-by date.” A second taste seemed to confirm this, even though it didn’t smell bad, so I threw all the soup away. Next, I tried some toast… which also tasted horrible. I began to wonder whether I had gotten dehydrated through the night and just had a bad taste in my mouth.

After cleaning my teeth, brushing my tongue and gargling mouthwash, I also tried tea and even water, but to no avail. When the problem persisted on Sunday, I realised there was more to this than meets the taste buds; everything tasted like battery acid. It was time to do some internet searching. As is usual when searching medical symptoms online, I turned up all the usual scary cancer and tumour-related stuff, as well as some information on stomach ulcers, acid reflux and liver problems. However, none of the symptom descriptions seemed to match what was happening to me.

Finally I came upon a forum where people were discussing the exact problem I was having; namely a metallic, bitter taste at the back of the tongue that was exacerbated by food, particularly anything sweet. About halfway down the topic posts, someone mentioned pine nuts, and after that post the agreement flooded in from people around the world suffering the same problem after having recently eaten pine nuts. With this new information in hand, I narrowed my search to “pine nuts bitter taste” and suddenly I had my answer from an official source; the European Journal of Emergency Medicine:

Taste disturbances after pine nut ingestion M. Mostin Poisons Centre, Brussels, Belgium Case report: A colleague anaesthesiologist experienced two episodes of taste disturbances after pine nut ingestion. At the first time, he just consumed a handful of pine nuts. Two days later, he developed an episode of taste disturbances (bitter, metallic taste). The disturbances lasted a few days. He made a link between pine nuts and the taste disturbances after the second episode when his wife and friends who shared with him a dish prepared with the same pine nuts complained of a persisting bitter taste sensation 2 days after the meal. Examination of the pine nuts revealed they were oxidized and not fit for consumption. No fungal contamination was found. No explanation was found for the taste disturbances. In the following months, six similar cases were reported to the Poisons Centre. The pine nuts involved in those cases were imported from China. The pine species remain unidentified. Analysis on pesticide residues and heavy metal did not reveal any contamination. One member of the medical team of the Poisons Centre tested on himself several brands of pine nuts and experienced two separate episodes of taste disturbances with the pine nuts imported from China. The phenomenon remained unexplained.

A student in pharmacy undertook chromatographic examinations on two samples involved in the taste disturbances and compared them with pine nuts from other origins. This led to the isolation of constituants compatible with triglycerids, formed by 16-18°C unsaturated fatty acids. The role of those triglycerids in the taste disturbances remains hypothetic.

So there you have it. And if you do further searching of your own, you’ll find much more information out there (even Wikipedia: wikipedia.org/wiki/Pine_nut#Risks_of_eating_pine_nuts). But I have yet to find anything about a cure, other than patience. I have also discovered that peppermint tea and peppermint green tea are the only things I’ve tried so far that don’t taste horrible. I’m on day three now, so hopefully it won’t last too much longer.

There is still debate on the forums I’ve read about whether or not roasting the nuts makes a difference, but I can tell you that for me it did. I served my rocket salad to eight people a few weeks ago with a generous helping of roasted pine nuts on each, and no one had this problem.

Unfortunately, there doesn’t seem to be any law in Norway that requires food to disclose its origin on its labelling. My pine nuts don’t say anything about where they were imported from. However, in all the information I read, it was Chinese imported pine nuts that caused this problem. Check your labels and if you experience the same thing, contact your local consumer affairs branch, or possibly poisons information if you are particularly concerned. As far as I know, there’s no danger, just a nasty, nasty taste for several days.