Onions are members of the Allium genus of flowering plants that also includes garlic, shallots, leeks, and chives.
These vegetables contain various vitamins, minerals and potent plant compounds that have been shown to promote health in many ways.
1. Packed With Nutrients
Onions are nutrient-dense, meaning they’re low in calories but high in vitamins and minerals.
One medium onion has just 44 calories but delivers a considerable dose of vitamins, minerals, and fiber.
This vegetable is particularly high in vitamin C, a nutrient involved in regulating immune health, collagen production, tissue repair, and iron absorption.
Vitamin C also acts as a powerful antioxidant in your body, protecting your cells against damage caused by unstable molecules called free radicals.
Onions are also rich in B vitamins, including folate (B9) and pyridoxine (B6) — which play key roles in metabolism, red blood cell production and nerve function.
Lastly, they’re a good source of potassium, a mineral in which many people are lacking.
In fact, the average potassium intake of Americans is just over half the recommended daily value (DV) of 4,700 mg.
Normal cellular function, fluid balance, nerve transmission, kidney function, and muscle contraction all require potassium.
Antioxidants are compounds that inhibit oxidation, a process that leads to cellular damage and contributes to diseases like cancer, diabetes and heart disease.
Onions are an excellent source of antioxidants. In fact, they contain over 25 different varieties of flavonoid antioxidants.
Red onions, in particular, contain anthocyanins — special plant pigments in the flavonoid family that give red onions their deep color.