Onions are a nutrient dense food – they are high in nutrients and low in calories. There are different types of onions and their flavor can vary from sweet and juicy to spice and pungent. The most common types are yellow, red and white onion.
They are rich in flavonoids, which are mostly concentrated in outer layers, so be careful when you are peeling onions not to peel too much.
Onions are the most popular member of allium family. Studies have shown that allium vegetables reduce cancer risk, especially stomach and colorectal cancers.