Onions, just like garlic, are members of the Liliaceae plant family. After broccoli, Brussels sprouts, shallots and celery, onion is one of the richest sources of polyphenols. These are one of the best types of phytonutrients and include both tannins (as found in red wine), and flavonoids, which are great at protecting against many unhealthy strands of bacteria. As well as their natural antibiotic powers, onions are thought to help prevent certain cancers and lower the risk of diabetes and neurodegenerative disorders, such as Alzheimer's and Parkinson's disease. They also help protect the heart, help maintain strong bones, and at the same time lower the risk of arthritis and asthma.

A rich source of: vitamin C, manganese, vitamin B6, folate, potassium.