Lettuce originated in Asia and has been cultivated since Roman times. It is a leafy green that is 95% water, making it low in calories. Lettuce contains vitamins A, C, E, and B1, as well as antioxidants like zeaxanthin and lutein that are good for heart health and may have anticancer properties. The United States has the largest lettuce production worldwide, followed by China, Spain, and Canada, while in Greece around 19,000 hectares of land are used to cultivate about 25,000 tons of lettuce annually.