Olive, With a Twist
The leaves of the olive tree are as beneficial as the famous oil.
Okay class, it’s time for a beneficial botanicals pop quiz. Raise your hands—how many people here know that olive oil is good for you? The whole room...not surprising. Now—how many know that olive leaf is also good for you? There’s not quite so many hands up this time. Let the lesson begin.
The olive tree occupies a prominent place in ancient history and no wonder: Olives and the oil they contain were (and are) dietary staples in the Mediterranean world. (The Greeks were so enamored of the olive tree that they ascribed its creation to the goddess Athena.) But the leaf of this venerable tree has also made historical appearances, generally as a folk remedy for bringing down fevers. The mechanism behind that action didn’t come to light until scientists were able to isolate a substance called oleuropein, responsible for both the bitter taste of uncured olives...and the tree’s hardy nature and resistance to bugs and bacteria.
In the laboratory oleuropein extract has been as tough on many of the bacteria and viruses that plague human beings as it is on the olive tree’s natural enemies, a finding which helps explain why olive leaf has traditionally worked so well in fighting fevers (a sign of infection). Various types of rhinovirus (common cold), influenza and herpes viruses have been numbered among oleuropein’s victims, along with the bacterial bad guys Escherichia coli (a strain of which can cause food poisoning) and Staphylococcus aureus (the prime suspect in many hospital-acquired infections).
Viruses are especially difficult to vanquish—antibiotics, as anyone suffering from the flu can tell you, don’t touch these tiny marauders. Olive leaf’s power lies in its ability to thwart viruses from replicating; no replication means no new viruses, which means no spread of infection. Olive extract can also incite immune-system cells into gobbling up harmful micro-organisms.
In addition to thwarting microbes, olive leaf promotes better circulatory health. The white-coat crowd has discovered that oleuropein extract relaxes constricted arteries, which results in reduced blood pressure. And olive not only reduces blood-sugar (glucose) levels but also serves as an antioxidant, a substance that can mop up harmful molecules known as free radicals. Given that oxidation plays a key role in the development of diabetic complications, both actions make olive leaf an intriguing option for people with diabetes. What’s more, oxidation also affects LDL cholesterol, turning it into the bad stuff that clogs arteries; olive leaf appears to interfere with this insidious process. This triple action—the ability to reduce blood pressure, glucose and LDL oxidation—may give olive leaf an important role in fighting metabolic syndrome, a cluster of health woes that helps fuel the world’s epidemic of cardiovascular disease.
The latest news from the olive grove: What boosts your blood may also benefit your bones. French researchers, intrigued by the low occurrence of osteoporosis among people who consume olive-heavy Mediterranean diets, found that female rats who received oleuropein showed less inflammation-induced bone loss than those fed standard rat chow (Clinical Nutrition 2006 online).
Surprised to learn that the olive tree’s leaf is just as valuable as its fruit? It’s true—and olive leaf deserves to go straight to the head of the class.