Lettuce is one of popular green leafy-vegetables. Lettuce seeds were used to produce oil and by the late 20th century the consumption of lettuce had spread throughout the world. Its crispy, green/crimson-red leaves are one of the incredible sources of essential nutrients that benefit health. Indeed, it is among the most sought-after greens, be it in your crunchy green salads or healthy sandwiches. Lettuce leaves carry good amounts of vitamins and minerals.