Pine Nut Syndrome (PNS) – Alternatively termed as ‘Pine Mouth’
WHAT IS PNS?
- Characterized by a delayed bitter / metallic-type taste disturbance
- Occurs 1-3 days after the ingestion of good-tasting pine nuts
- Symptoms mostly resolve within 1-2 weeks, some cases known to last for months
- Amplified by food and drink intake
- Dependent upon the type of food and the individual
- Most people are susceptible to PNS but are affected to different extents.
- Nature and intensity of the symptoms vary over the course of the episode, normally peaking within the first two days and tailing off at the end
- Occasional complaints of headache, nausea, throat discomforts, diarrhea and stomach pains accompany the symptoms of taste disturbance
WHO GETS PNS?
PNS is a phenomenon that has affected large numbers of people from all walks of life. The 434 survey cases spanned 23 countries (4 continents) and involved people of different ethnicity, ages, genders, health conditions and lifestyles (activity levels, smokers/non-smokers; alcohol drinkers/ non-drinkers; diets). See page ‘Who Sold Them!‘ for a full list of countries and retailers that sold problem pine nuts.
Almost all victims (96% of total) have previously consumed pine nuts and have no known allergies towards it, 11% of whom reported experiencing PNS multiple times as they were unable to associate the problem to pine nuts in the past when there was less available information about this problem.
Reported cases of shared pine nuts mostly involved (1) all members of the group noticing symptoms OR (2) symptomatic individuals having consumed a larger quantity of pine nuts than the other members of the group [to be addressed in a moment].
Of 21 students and professors of Wageningen University that ingested 1g and 10g (the latter amount for those who did not get symptoms from 1g) from a supermarket batch consisting of 100% P. armandii pine nuts, 19 were afflicted with noticeable symptoms that were characteristic of PNS (subjects filled in a daily logbook describing their observations). The pine nuts ingested were within expiry date and tasted good at the time of ingestion (not rancid).
PINE NUTS THAT CAUSE PNS
Survey cases involved raw and/or roasted, rancid and non-rancid, fresh and stored, expired and non-expired pine nuts, mostly of Chinese origin except for Trader Joe’s pine nuts that labelled ‘Product of Russia and/or Korea’. The average estimated amount of pine nuts consumed was about 30g, with trigger dosages as low as 2 or 3 seeds. The 56 complaint samples collected were found to consist of pure P. armandii or a mixture of P. armandii with one or two of 6 other species (See page: ‘Pine Nut Species‘ for information on the different species).
Species composition of 56 complaint samples
DESCRIPTORS OF PNS SYMPTOMS
Bitter and bitter-metallic were most often used to describe the nature of the taste disturbance, although it was reported that the quality and intensity of the taste disturbance varied with different types of foods and at different stages of the PNS episode. (See page: ‘Food Effects’ for how the taste disturbance varies with different types of food). The chart below shows the frequency which other types of off-tastes were experienced.
Both taste disturbance and these physical symptoms are often signals of underlying physiological disturbances and should not be so quickly dismissed as a non-health issue (as is done by many food authorities). No research proof of health problem does not equate no health problem! Please read the page on ‘Health Issue‘ for further explanations on the adverse impacts of PNS.
[Updated: 5 June 2011]