Pine Nuts May Be To Blame For That Bitter Aftertaste : Shots - Health News Scientists haven't documented any long-term health effects from eating bad pine nuts, just an annoying, temporary metallic taste in the mouth.

Pine Nuts May Be To Blame For That Bitter Aftertaste

Pine Nuts May Be To Blame For That Bitter Aftertaste

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Selena Simmons-Duffin demonstrates the face that comes with Pine Mouth syndrome. Ilse Bendorf hide caption

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Ilse Bendorf

You know it's a bad sign when the bride texts her guests to ask if anyone has a metallic taste in their mouth.

That was Morning Edition Producer Selena Simmons-Duffin's first clue that she'd been struck by a weird food syndrome known as Pine Mouth.

What is Pine Mouth you ask? It's a vile, bitter-metallic taste in your mouth that you just can't shake after eating pine nuts. "Anything I eat or drink tastes revolting," writes The Greasy Spoon, one of many food blogs to complain about the problem recently. The nasty taste can last a few days or up to two weeks.

For Simmons-Duffin, it was the wedding rehearsal dinner that done it. "We had this lovely salad with arugula, goat cheese and the fated pine nuts," she told Shots.

Simmons-Duffin said the good news is you don't really feel sick. The condition is mostly just an annoyance, because nothing tastes good for awhile.

When Simmons-Duffin and some ME colleagues posted a Facebook thread on Pine Mouth, they were surprised by how many people jumped into the conversation. "For a post at 1 a.m., 22 comments made for quite a lively thread" said Simmons-Duffin.

So how many people experience Pine Mouth? Official numbers are hard to come by. The FDA documented 53 complaints in 2009. They don't have updated numbers for this year, but it's likely that many cases don't get reported.

An FDA spokesperson said that most cases are not considered illnesses, since there are usually no accompanying symptoms. "Taste disturbance" is the category FDA gives Pine Mouth.

No one is certain what causes it. One theory is that people don't store the nuts properly, so they go bad.

"We know from agricultural research that pine nut oil can go rancid quickly," said Dr. Marc-David Munk of the University of New Mexico. Munk got interested in Pine Mouth after he came down with it.

In Munk's case, he ate a handful of pine nuts from a restaurant salad bar. He published a paper in the Journal of Medical Toxicology about his experience. Since then, he says he receives a couple of emails a day from people who are curious to know more.

Munk says there's another theory about what causes the bitter taste: Chinese imports. Researchers in Switzerland recently did a chemical analysis of imported pine nuts and identified two species that have not traditionally been part of the food supply.

"One was the Chinese White Pine and the other was the Chinese Red Pine," said Munk. So the second theory is that Pine Mouth is caused by an inedible species of pine nuts that have made it onto the market.

The problem is, there's no way for most consumers to tell. They look the same on the salad, so you might want to approach these nuts with a little caution. If you've been struck, there's a Facebook group you can join.

For more on the mysterious Pine Mouth syndrome, check out my Morning Edition piece today.