ISMNT News #52. The Mediterranean diet is associated with a lower incidence

of CHD and cancer. The protective agents remained, however, ill-defined.

There was a feeling that the high proportion of the monounsaturated oleic

acid might be involved. The present mail provides a more rational

explanation. Phenolic compounds with antioxidative properties present in

olive oil might be the protective agent. It has previously been shown that

phenolic components of olive oil can inhibit platelet function and

eicosanoid formation in vitro (Thromb Res 1995 Apr 15;78(2):151-160). It

appears, however, that these beneficial compounds are present only in extra

virgin olive oil which is obtained by physical pressure from a whole fruit.

If other types of olive oil preparations have lost these beneficial

components, they would just be ordinary oils.

The key reference is by:

Visioli F, Bellomo G, Galli C

Institute of Pharmacological Sciences, University of Milan, Italy

Free radical-scavenging properties of olive oil polyphenols

Biochem Biophys Res Commun 1998 Jun 9;247(1):60-64

Plants in the Mediterranean basin, such as vine and olive trees, have

developed an array of antioxidant defences to protect themselves from

environmental stress. Accordingly, the incidence of coronary heart disease

and certain cancers is lower in the Mediterranean area, where olive oil is

the dietary fat of choice. As opposed to other vegetable oils, extra virgin

olive oil, which is obtained by physical pressure from a whole fruit, is

rich in phenolic components that are responsible for the particular

stability of the oil.

We have investigated the scavenging actions of some olive oil phenolics,

namely hydroxytyrosol and oleuropein, with respect to superoxide anion

generation, neutrophils respiratory burst, and hypochlorous acid. The low

EC50S indicate that both componds are potent scavengers of superoxide

radicals and inhibitors of neutrophils respiratory burst: whenever

demonstrated in vivo, these properties may partially explain the observed

lower incidence of CHD and cancer associated with the Mediterranean diet.