-Olive tree (Olea europaea, Oleaceae) leaves have been widely used in traditional herbal medicine to prevent and treat various diseases especially in Mediterranean countries. 50gm Olive leaf benefits: reduces cardiovascular risk, like atherosclerosis. lowers blood pressure. helps treats type 2 diabetes. supports weight loss. eliminates free radicals. boosts immunity. fights herpes. reduces inflammation. Make Your Own Olive Leaf Tea Pour hot water over loose leaves (bring water to a boil and let cool for a minute or two so you don't burn the leaves). Use loose leaves in a tea ball and steep 1 teaspoon (5 grams) of dried leaves in 1 cup (250 ml) of hot water for 10–15 minutes.