The compound, called oleocanthal, inhibits COX enzymes in the same dose-dependent manner as ibuprofen, a member of the nonsteroidal anti-inflammatory class of drugs, write Paul A. S. Breslin from the Monell Chemical Senses Center in Philadelphia and colleagues in a brief communication in the 1 September issue of Nature.
The findings could help explain olive oil's widely reported health benefits. Numerous studies have pointed to a link between high consumption of the product, a common ingredient in traditional Mediterranean food, and the low rates of heart disease in many south European countries. Other studies suggest it may prevent cancer.
But few studies have identified a clear mechanism for these effects.
Breslin and his colleagues say that oleocanthal in newly pressed extra-virgin olive oil and ibuprofen both produce a strong stinging sensation in the throat, an indicator of a "shared pharmacological activity, with oleocanthal acting as a natural anti-inflammatory compound that has a potency and profile strikingly similar to that of ibuprofen."
The researchers carried out a study on different premium olive oils and found a strong positive link between levels of oleocanthal and its intensity as a throat irritant. Similar results were achieved in tests of a synthetic version of oleocanthal they created, confirming that this compound is in fact the active ingredient in olive oil.
They demonstrated that oleocanthal, like ibuprofen, inhibits so-called COX enzymes so that a 50-gram daily dose of olive oil is equal to about 10 per cent of the ibuprofen dose recommended for pain relief in an adult.
This means it is unlikely to cure a headache but regular consumption of olive oil might have some of the long-term health benefits of ibuprofen, the researchers say. These include benefits for heart health.
It is well known that aspirin, another COX-inhibitor, protects the heart. Ibuprofen reduces the risk of developing some cancers and also prevents blood platelets from clumping together, which can block arteries.
Ibuprofen has also been shown to reduce levels of an Alzheimer's disease-related protein in mice.
"Our findings raise the possibility that long-term consumption of oleocanthal may help to protect against some diseases by virtue of its ibuprofen-like COX-inhibiting activity," Breslin and colleagues write.