Why do some pine nuts cause a bad taste in your mouth that can last for weeks?
The reason I make pesto with walnuts instead of the more traditional pine nuts isn’t only because walnuts are probably healthier with 20 times more polyphenols, but also because of a mysterious phenomenon known as PMS. Not that PMS. Pine mouth syndrome is characterized by what has become my favorite word of the week: cacogeusia, meaning a bad taste in your mouth. You can get cacogeusia from heavy metal toxicity, seafood toxins, certain nutritional and neurologic disorders, or the wrong kind of pine nuts. “Termed ‘Pine Mouth’ by the public, cases present in a roughly similar fashion: a persistent metallic or bitter taste beginning 1–3 days following ingestion of pine nuts lasting for up to 2 weeks.”
As I discuss in my video Pine Mouth Syndrome: Prolonged Bitter Taste from Certain Pine Nuts, thousands of cases have been reported, and it doesn’t seem to matter if the pine nuts are raw or cooked. Could the cause be an unidentified toxin present in some varieties of non-edible pine nuts? Indeed, “out of more than 100 species of the Pinus genus, [only] 30 are considered to be edible by the Food and Agriculture Organisation of the United Nations.”
We don’t know it’s the Chinese white pine nuts, though, until we put it to the test. Researchers gave study participants six to eight Chinese white pine nuts. Most hadn’t ever heard of pine mouth syndrome, and they all developed symptoms. We still don’t know exactly what it is in those nuts that causes such a bizarre reaction. We know to stay away from those kinds of pine nuts.