Beware of pine mouth

As a salad topping, a pesto ingredient and a healthy snack, the pine nut is popular. But it’s left a bad taste — or, in the worst-case, no taste at all — in the mouths of thousands of people worldwide.

While people have ingested pine nuts for thousands of years, only in the past decade has “pine mouth” started occurring.

The cases all follow a similar pattern: A couple of days after eating pine nuts, raw or in pesto, people notice a bitter, metallic taste they can’t get rid of. The problem lingers for one to two weeks, and all other foods taste terrible.

In the past two months, an uptick in the number of pine-mouth cases has been reported. Nobody knows why. In fact, even though it’s been scientifically studied, nobody can explain what makes it happen in the first place.

A paper published in the European Journal of Emergency Medicine in 2000 reported that the majority of cases came from Chinese pine nuts, but when they were studied in a lab they contained no fungi, no chemicals, no pesticides and no heavy metals. After purposely giving himself a dose, the scientist who studied the foul-tasting pine nuts wrote, “no explanation was found for the

taste disturbances.”

After noticing that some people didn’t get sick even though they ate the same batch of pine nuts, researchers in the UK tried to pinpoint the cause but concluded it was not due to allergies: “Possibly the oils in the nuts have gone rancid because of poor storage and just as caffeine increases some people’s heart rate more than

others, some people may be susceptible to these oils, and some not.”

Pine nuts are an important part of vegetarian and vegan diets, so for many people, giving them up is not an option. Instead, treat them like a drug — only take from sources you know and when in doubt, throw it out.

(Image via Flickr: Daniel Eizans)