Olives alive: extra-virgin oil has anti-inflammatory properties.

Besides taste, scientists now offer another reason why people should drizzle their food with extra-virgin olive oil. A chemical analysis suggests that a molecule isolated from this grade of oil, which comes from the first pressing of the fruit, has anti-inflammatory effects similar to those of ibuprofen. The finding may explain some of the health benefits associated with the Mediterranean diet.

This style of eating, now popular beyond its origins in southern Europe, consists mostly of vegetables, with small servings of meat, moderate amounts of wine, and plenty of olive oil. Since the 1950s, scientists have known that people who follow this diet have lower rates of dementia, heart disease, strokes, and some types of cancer than do people who eat other combinations of foods. Researchers remain unsure about which specific foods are responsible for these positive effects, notes Paul Breslin of the Monell Chemical Senses Center in Philadelphia.

At a recent meeting in Italy, Gary Beauchamp, Breslin's colleague at Monell, tried some flesh-pressed extra-virgin olive oil. He instantly felt stinging sensations in his throat that reminded him of similar experiences he'd had during studies of liquid ibuprofen's sensory properties.

This chance observation, which Beauchamp's colleagues later replicated, made the researchers wonder whether extra-virgin olive oil and ibuprofen had pharmacological similarities as well. To investigate, the collaborators isolated the molecular component of olive oil responsible for the stinging sensation, which they named oleocanthal. However, an analysis showed that the molecule has no structural similarities with ibuprofen.

To confirm that they indeed had isolated the component of olive oil that caused the stinging sensation, the scientists made synthetic copies of oleocanthal in the lab. After spiking non-irritating corn oil with small amounts of the compound and doing a taste test, the scientists experienced the characteristic stinging in their throats.

The team then tested whether oleocanthal could chemically inhibit two inflammation-inducing enzymes, cyclooxygenase (COX) 1 and COX 2. That's what ibuprofen does to produce anti-inflammatory and analgesic effects. The tests showed that identical concentrations of oleocanthal and ibuprofen were equally potent in inhibiting both enzymes. The scientists report their findings in the Sept. 1 Nature.

Breslin notes that the concentrations of oleocanthal in extra-virgin olive oil yield an amount of the chemical far lower than the amount of ibuprofen taken in a typical dose.

"If you had a headache and wanted to treat it with olive oil, you'd have to drink a whole glass," Breslin says. Even so, he adds, the overall amount of oleocanthal in olive oil consumed by someone eating a Mediterranean diet might ease inflammation, a known risk factor for many diseases.

The study is "interesting and intriguing," says Frank Hu, a nutrition researcher at the Harvard School of Public Health in Boston. However, he suggests that oleocanthal is only one of many health-promoting components in the Mediterranean diet or even in olive oil alone. "The bottom line is that olive oil has many biologically important compounds that impact our health. It's difficult to attribute the effects of olive oil to one compound" he says.