Though all vegetables are beneficial to health, certain varieties provide additional advantages. Onions are members of the Allium genus, which also includes garlic, shallots, leeks, and chives. Onions are high in nutrients and have been linked to a variety of health benefits such as improved heart health, better blood sugar control, and increased bone density. These vegetables contain a variety of vitamins, minerals, and powerful plant compounds that have been shown to benefit health in a variety of ways. In fact, onions' medicinal properties have been known since ancient times, when they were used to treat ailments such as headaches, heart disease, and mouth sores. This vegetable is high in vitamin C, a nutrient that aids in immune health, collagen production, tissue repair, and iron absorption.

Furthermore, onions are high in fibre and serves as good prebiotic, both of which are essential for good gut health. Prebiotics are types of nondigestible fibre that are broken down by beneficial gut bacteria. Gut bacteria consume prebiotics and produce short-chain fatty acids such as acetate, propionate, and butyrate. According to studies, these short-chain fatty acids improve gut health, boost immunity, reduce inflammation, and improve digestion.