With this union, oxidation occurs, and the LDL-cholesterol begins to build up on blood vessel walls. This narrows blood vessels and might eventually result in a number of cardiovascular problems. OPCs in tea might find their way into the bloodstream and hook up with the defenseless LDL-cholesterol. The OPCs fight off the free radicals and save the vessel walls from damage. What makes the color, texture, fragrance, and antioxidant content different is the degree of processing.
Green tea is the least processed.
The leaves are chopped and rolled and then immediately steamed or heated. Black tea is also chopped and rolled, but then the leaves are exposed to air for several hours. This causes the tea to oxidize, which gives it its black color and destroys many of the OPCs. However, black tea has its own antioxidants, known as theoflavins and thearubigins. These are just beginning to be studied.