Olive extract could improve blood flow, boost cardio health
dietary supplementation with the olive extract, oleuropein, could
boost blood flow and reduce heart attack risk.
If the results from the rabbit model can be reproduced in a human setting it may offer an alternative area of marketing for dietary supplements containing the extract currently marketed for their reported benefits for blood pressure, blood glucose levels, and bone health.
A large body of science has linked adhering to the Mediterranean diet, rich in olive oil and other antioxidant sources, to lower rates of cardiovascular disease and other health diseases.
The new research, published in the August issue of the Journal of Nutrition (Vol. 136, pp. 2213-2219), claims to be the first experimental study in vivo that suggests the possibility of using an oleuropein to improve blood flow and boost cardiovascular health.
"Oleuropein, for three or six weeks, reduced the infarct size, conferred strong antioxidant protection and reduced the circulating lipids," reported lead researcher Ioanna Andreadou from the University of Athens.
The researchers supplemented the diets of rabbits consuming a normal or a high cholesterol diet. Daily doses of 10 or 20 milligrams of oleuropein per kilogram of body weight were given for three to six weeks.
The effects of these diets were evaluated in rabbits subjected to coronary ischemia (inadequate blood supply caused by blockage of blood vessels) which leads to increases in oxidative stress and heart attack.
It was found that rabbits consuming the normal diet had significantly reduced heart attack size when supplemented with the lower dose of the olive extract (16.1 per cent after three weeks compared to 48 per cent in the control/unsupplemented group).
The 20mg oleuropein dose for the normal diet reduced the size of the infarction to 21.7 per cent, and only this dose had an protective effect on the rabbits fed the high cholesterol diet (34.7 per cent infarction size versus 52.8 per cent for the cholesterol-fed control group).
"Oleuropein decreased the plasma lipid peroxidation product and protein carbonyl concentrations compared with the control groups, in which these factors increased relative to baseline due to ischemia and reperfusion," reported the researchers.
While significant further research needs to confirm or refute these findings, the results appear promising. Moreover, effects observed in rabbits or other animals are not guaranteed to be transferable to humans in everyday life. The results should therefore be treated with a cautious welcome.
Dietary supplements containing oleuropein are currently available in Europe by Belgian company BioActor, licensees of the worldwide rights to the patents held by France's INRA patents on using olive polyphenols for osteoporosis prevention in food, supplements and herbal medicines.