A young version of a white onion, the spring onion's newbie stems and small bulb supply a wealth of nutrients. They're low in calories but high in vitamin C and quercetin; a type of phytonutrient that studies have found to be a potent cancer fighter. In fact, onion consumption (several servings per week) in general helps lower risk of colon cancer. Add sliced spring onions to salads or as a topping for grilled proteins like fish, chicken and lean beef—their mild flavor is a welcome addition. Avoid peeling off too many outer layers when prepping spring onions, as this is where much of the quercetin lies. - Dr. Liz Applegate