BRISBANE, Australia—Results from an Australian study strongly suggested olive leaf extract (OLE), a staple in the Mediterranean diet that contains polyphenols such as oleuropein and hydroxytyrosol, reverses the chronic inflammation and oxidative stress that induces the cardiovascular, hepatic and metabolic symptoms in diet-induced diabetic obese rats without changing blood pressure (JNutr. 2010;140(5);946-953). Male Wistar rats were fed either a cornstarch diet (CS) or a high-carbohydrate, high-fat (HCHF) diet for a total of 16 weeks. Diets of the treatment groups [CS + olive leaf extract (OLE) and HCHF + OLE] were supplemented with 3 percent OLE after eight weeks of being fed their respective CS or HCHF diets for a further eight weeks. After 16 weeks, HCHF rats developed signs of metabolic syndrome, including elevated abdominal and hepatic fat deposition, collagen deposition in heart and liver, cardiac stiffness, and oxidative stress markers with diminished aortic ring reactivity, abnormal plasma lipid profile, impaired glucose tolerance and hypertension. Compared with HCHF rats, those in the HCHF+OLE group had improved or normalized cardiovascular, hepatic and metabolic signs with the exception of elevated blood pressure.
