Adapted from an article in the New Haven Register by Dr. David Katz, July 1, 2018
In late June 2018, Yale University hosted the Mediterranean Diet Roundtable conference. Among the presentations were two by world-leading experts in the bioactive components of olive oil, Eleni Melliou, PhD, and Prokopios Magiatis, PhD, both from the University of Athens.
Among those many compounds is oleocanthal, a polyphenol and potent antioxidant found in olives. It is established to inhibit COX1 and COX2 enzymes. What does that mean? The first, inhibition of COX1, is what ibuprofen does. The second, inhibition of COX2, is what Celebrex does. So, oleocanthal-rich olive oil (let’s call this “OROO”) has potent anti-inflammatory, and potentially analgesic (pain reducing) properties. What does the research show?
As presented by my colleagues from Athens, a study of OROO in 200 men in Spain showed a linear increase in protective HDL cholesterol, and a decline in LDL cholesterol. In a study of 24 women with hypertension, OROO was found to lower blood pressure, improve endothelial function and lower CRP, an important inflammatory marker. Multiple other studies cited by my Greek colleagues replicated these effects.
OROO has been shown to inhibit platelet aggregation as well, the mechanism responsible for acute myocardial infarction. Like ibuprofen, aspirin inhibits COX1, so there is a clear case for the actions of compounds in olive oil to resemble effects seen with these drugs.
Aspirin is used routinely as a cardioprotective agent because it inhibits platelet aggregation.
Oleocanthal derived from olive oil has been shown to induce the clearance of the plaques associated with Alzheimer’s disease from the brains of experimental animals. Results of a human trial, announced just last month, showed an improvement in Alzheimer’s symptoms, and delayed progression of the disease, with OROO.
Oleocanthal has also been shown to induce cancer cell death. In an ongoing study of patients with chronic lymphocytic leukemia, OROO daily for three months significantly reduced the numbers of cancerous white blood cells relative to placebo.
Now, let’s put it all in context.
The active compounds in olive oil, like oleocanthal, are highly concentrated in the unripe olives used to make cold-pressed, extra virgin olive oil. They are almost completely absent from the ripe olives used to make the lesser varieties of olive oil that often populate the shelves of American supermarkets. Details matter.
The above does not make the case that olive oil, or a Mediterranean diet, is required for good health. But the above certainly does make the case that genuinely good olive oil has genuinely good health effects. No surprise, then, that of the world’s five Blue Zone populations, two have OROO-rich, Mediterranean diets. That, too, is evidence that matters.
I find the weight of evidence regarding extra virgin olive oil, OROO, and oleocanthal extremely compelling. I am fully persuaded that “good” olive oil is a signature contributor to the many benefits of one of the world’s truly great diets.
I am also persuaded, however, again based on the full weight of relevant evidence, that no one food or nutrient accounts for the net effects of the overall diet. The one true toxin I see all too often in the mix—corrosive to consensus, understanding, common ground, and common cause—is cherry-picked science to make the case for any given diet. The pits are concentrated there, so be careful not to swallow that!