Onions are part of the allium family of vegetables and herbs, which also includes chives, garlic, scallions, and leeks. Allium vegetables have been cultivated for centuries for their characteristic, pungent flavors and for their medicinal properties. Onions can vary in size, shape, color, and flavor. The most common types are red, yellow, and white onions. Flavors can be sweet and juicy to sharp, spicy, and pungent, often depending on the season in which they are grown and consumed. It is estimated that 105 billion pounds of onions are harvested each year, worldwide. According to the Food and Agriculture Organization of the United Nations (FAO), China is the biggest producer. The possible health benefits of consuming onions include lowering the risk of several types of cancer, improving mood, and maintaining the health of skin and hair.