Discuss as:

'Pine mouth syndrome' leaves a bitter taste

It’s a food lover’s nightmare: One minute you’re enjoying a delicious bit of pine nut pesto and the next, everything you taste is nauseatingly bitter.

That’s what happened to Christian Niles, a 29-year-old software engineer from San Francisco.

“I made a cream sauce with about a cup of pureed pine nuts and about an hour after the meal, I had a cookie with blueberries in it and the blueberries were really bitter,” says Niles. “Then everything just turned bitter.”

A bitter-metallic taste that hangs around for a week or so after eating the seeds is the hallmark of “pine mouth syndrome,” a curious condition that a recent paper in the Journal of Medical Toxicology calls “an emerging problem.”

First documented in 2001, the phenom remains unexplained and seems to involve raw, cooked or processed pine nuts of various species. While there’s been speculation the condition is associated with pine nuts imported from China, Niles says the batch that caused his taste distortion came from Italy.

It’s a fairly rare syndrome, but because pine nuts are becoming increasingly popular in dishes such as pesto and gourmet salads, reports of more cases are popping up.

The condition is mostly unexplained, but it could be nerve cells in the mouth misfiring, says Dr. Alan Hirsch, founder and neurological director of the Smell & Taste Treatment and Research Foundation in Chicago. “At this moment, we think it’s the sweet taste receptors that aren’t firing off. In response to the lack of the taste of sweet, bitter come out more.”

He compares it to the “artichoke effect.”

“When you eat artichokes and then you drink red wine, the red wine tastes bitter,” he says. “The same thing happens if you brush your teeth and drink orange juice. Hirsch says he’s not only seen cases of “pine mouth,” he’s also had people come to him with “pineapple tongue” and “tomato tongue.” In all three cases, a bitter taste persists after people eat these particular foods.

Taste distortions can also be caused by certain medications, he says.

If you think you’ve got the strange condition, you don’t have to wait until the bitter end. A little sugar or artificial sweetener in food (or on the tongue) can help, as well as rinsing your mouth with watered-down milk of magnesia or chewing (non-mint-flavored) gum, says Hirsch.

Have you ever had a weird reaction to pine nuts or any other food? Share your comments!