Top 10 Health Benefits of Oregano. Best known as the “pizza herb,” oregano has been gaining popularity as a natural remedy for many common health problems. Both fresh and dried oregano leaves have volatile oils with carminative, stomachic, diuretic, diaphoretic, expectorant, antibacterial, antioxidant, antimicrobial and mild tonic properties. Oregano is also an excellent source of vitamins and minerals. It is high in vitamins A, C, and E complex, as well as zinc, magnesium, iron, calcium, potassium, copper, manganese and niacin. Here are the top 10 health benefits of oregano.