Tomatoes are the major dietary source of the antioxidant lycopene, which has been linked to many health benefits, including reduced risk of heart disease and cancer. They are also a great source of vitamin C, potassium, folate, and vitamin K. Usually red when mature, tomatoes can also come in a variety of colors, including yellow, orange, green, and purple. What’s more, many subspecies of tomatoes exist with different shapes and flavor.