Wheatgrass is rich in magnesium since this is the core mineral found in every chlorophyll molecule. Magnesium has relaxing and dilating effect on the blood vessels. This means that it can relax constricted blood vessels and make it larger so that blood can flow freely and pressure on the walls of the blood vessels will be lessened.
The antioxidants in wheatgrass prevent oxidation of cholesterol in the blood, which causes the cholesterol to stick to the walls of the blood vessels. Thus antioxidants prevent cholesterol plaque formation or atherosclerosis.