Saturday, August 25, 2012

What is Oleocanthal? (an irritating compound in virgin olive oil)

Virgin olive oils have been characterised by a stinging or burning sensation localised to the back of the throat that can have sufficient intensity to force involuntary coughing, but the compound/s responsible were unknown. 
The virgin olive oil contains different phenolic compounds such as phenyl acids, flavonoids and secoiridoids that are reported to have health benefits and contribute to oxidative stability and flavour. However, very little is known about the influence individual compounds contribute to the organoleptic properties.  Of particular interest was the stinging almost exclusively in the throat region, which was similar to the irritation elicited by the nonsteroidal anti-inflammatory drugs (NSAIDs) ibuprofen (Nurofen/Advil).  So, colleagues at Monell Chemical Senses Center in Philadelphia and I started to investigate the interesting irritant sensation associated with virgin olive oils in the hope that we could find the irritant compound.  It was a long process, but here is the short version.  
The irritating compound was isolated and identified using a combination of HPLC-G and NMR.  The irritating compound was synthesised, tasted and named oleocanthal (oleo-Latin for olive, canth-Latin for sting, al-for aldehyde).  Finally, the pharmacologic activity of oleocanthal was assessed and compared to ibuprofen. Oleocanthal, was a classic NSAIDs with potency superior to that of ibuprofen.
Taken together, these data are consistent with our hypothesis that the throat irritating compound in virgin olive oil is an ibuprofen-like antiinflamatory agent.  It is important to remember that the traditional Mediterranean diet is associated with reduction in many inflammatory related diseases.  We suggest long-term consumption of virgin olive oil containing oleocanthal (and many other phenolic compounds), with anti-inflammatory ibuprofen-like activity may enhance health and well being.  Assuming that an olive oil consumer in the high normal range ingests about 3 tablespoons of olive oil/day and that this oil contains up to 200 ug/g of oleocanthal, then the person would consume approximately 10% of the dosage of ibuprofen recommended for adult pain relief.  It is important to note virgin olive oil in this situation is no a pain reliving drug, rather it provides some protection for inflammatory response that occurs during food consumption. [1]

It is vital the olive oil is labelled ‘virgin’olive oil, otherwise the phenolics are not present.  To take full advantage of oleocanthal, the virgin olive oil should be peppery – some consumers do not like the peppery character.  And finally, olive oil is a yearly harvest, usually Autumn to Autumn – purchase local and fresh to maximize the potential health benefiting compounds.



  1. Great article - thanks. We've been doing some olive oil tasting recently. This was part of a 'guest' MSc project we hosted in our laboratories in which we've been developing reference flavour standards for olive oil. Until having sat down and tasted extra-virgin olive olive oil in the quiet of our taste room I'd never been really aware of just how pungent and peppery they can be - despite being a life-long olive oil consumer. We've been debating among ourselves what sort of compound might give rise to this unusual mouthfeel. Somehow we'd managed to miss this paper from Monell. And what a fascinating twist in the tail with respect to the anti-inflammatory effects.

    1. Thanks Bill, it is a fascinating compound and topic.