Olive leaf is the leaf of the olive tree (Olea europaea). Although olive oil is well known for its flavor and health benefits, the leaf has been used medicinally in various times and places.[1] Olive leaf and olive leaf extracts (OLE), are now marketed as anti-aging, immunostimulator, antioxidant, cardio protective, blood sugar regulating, anti-inflammatory and antibiotic agents. Though there is some laboratory evidence for these effects in biological standardization experiments (i.e., bioassays), clinical evidence in humans is inconclusive.
Clinical evidence has been conflicting regarding any blood pressure lowering effect of carefully extracted olive leaf extracts. Bioassays support its antibacterial, antifungal, and anti-inflammatory effects at a laboratory level. A liquid extract made directly from fresh olive leaves gained international attention when it was shown to have an antioxidant capacity almost double green tea extract and 400% higher than vitamin C