The new research by researchers from the Spanish Institute de la Grasa, and the University Hospital of Valme, report that, under their simulated in vitro conditions, the polyphenol-rich extra virgin olive oil exerted anti-bacterial effects against eight strains of H. pylori, three of which were said to be resistant to antibiotics.
"These results open the possibility of considering extra virgin olive oil a chemoprotective agent for peptic ulcer or gastric cancer, but this bioactivity must be confirmed in vivo in the future," wrote lead author Concepcion Romero in the Journal of Agricultural and Food Chemistry.
The researchers state that previous studies have shown that green tea, cranberry juice and certain other natural foods inhibit the growth of H. pylori, the only bacteria that can survive in the acidic environment of the stomach and known to cause peptic ulcers and gastritis.
The new study, the first to look at the potential anti-H. pylori role of olive oil polyphenols, used laboratory experiments to demonstrate that under simulated conditions the healthful phenolic compounds in extra virgin olive oil remain stable in the acidic environment of the stomach for hours.
Indeed, the results show that, under the simulated conditions, over half of the polyphenols found in olive oil could diffuse into the aqueous (water) phase of the gastric juices. Moreover, these polyphenols were found to exert the greatest anti-H. pylori activity.
"The results indicate that the secoiridoid aglycons are not hydrolysed in the acidic environment of the gastric juice," wrote Romero. "It has just been demonstrated that these secoiridoid aglycons, in particular the dialdehyde form of decarboxymethyl ligstroside aglycon, are the most powerful anti-H. pylori compounds of the olive oil."
The olive oil extract's anti-bacterial effects were found to be dose-dependent, and only the weakest extract (one per cent) failed to exert a significant bactericidal activity.
"In view of the low concentration required to exert bactericidal action against H. pylori by the dialdehydic form of decarboxymethyl ligstroside aglycon, it is promising to carry out studies in vivo with extra virgin olive oil to prevent and control peptic ulcers and gastric cancer caused by this bacteria," concluded the researchers.
The results of the study may keep consumer interest in olive oil high, following other studies linking the diet to lower incidence of cardiovascular disease (CVD) and certain types of cancer.
Indeed, Mintel's Edible Oils report said that the UK olive oil market has been on fire since 2000, growing by 39 per cent to date in order to break through the £100m mark.
Source: Journal of Agricultural and Food Chemistry Volume 55, Pages 680-686 "In vitro activity of olive oil polyphenols against Helicobacter pylori" Authors: C. Romero, E. Medina, J. Vargas, M. Brenes, A. de Castro