Olive Leaf Extract May Improve Vascular Functions
The polyphenols in the leaves of the olive plant have been shown to favorably modify a number of cardiovascular risk factors. The most recent study suggests that olive leaf extract supplementation may improve vascular function and lower inflammatory cytokines that have been linked with an increased risk of heart disease.
Participants in the study included 18 volunteers, half female and half male. They were given either an olive leaf extract containing 51 mg oleuropein and 10 mg hydroxytyrosol (HT) or a control on a single occasion. Following a 4 week wash out period, they were switched to the other intervention.
The researchers measured vascular function using digital volume pulse (DVP). In addition, blood collected at baseline, 1, 3, and 6 hours was cultured for 24 hours in the presence of lipopolysaccharide in order to examine cytokine production. Finally, they analyzed urine for phenolic metabolites by HPLC.
They found that both DVP-stiffness index and ex vivo IL-8 production were significantly lower in the olive leaf extract group when compared with the control. They also noted the excretion of several phenolic metabolites, mainly oleuropein and HT, which peaked in urine after 8-24 hours.
Researchers from the University of Reading conducted the study. It was published online ahead of print on June 8, 2015, in the British Journal of Nutrition.
Previous studies suggest that olive leaf extract may help lower blood pressure, triglycerides, and cholesterol. It is available in supplement form.