Historical evidence for the use of olive leaves dates back thousands of years.  Across the globe today, olive leaf is still used as a healthy tonic.  In modern times much study has been done of one of its primary constituents, oleuropein, for its strong antioxidant health benefits. Olive Leaf provides a rich supply of oleuropein, reinforcing the immune function by combating free-radicals.  Coupled with a wide range of natural polyphenols, powerful antioxidant properties are achieved by Olive Leaf, sparking interest for its support of the body. European research indicates Olive Leaf to have strong properties of fighting microbes, too.