In germ-filled classrooms, it takes just one sick child to infect classmates whose immune system is even slightly compromised. Almost 22 million school days are missed because of colds each year. And 38 million days are missed due to the flu virus. What can parents do to help kids stay healthy while in school? Encourage healthy eating of the right kinds of foods that boost immunity. While school breakfasts and lunches are far from perfect, this study suggests school foods are getting healthier, maybe even healthier than what some kids are getting at home. So heads-up parents! We’ve said for years that disease cannot survive in healthy cells. As long as you are insisting your kids eat nutritious foods that boost their immune system—and skip those loaded with toxins—they’ll stay healthy and strong throughout the school year. So here are our top six foods your child can eat while at school: Walnuts Just seven walnuts a day can have amazing health benefits. In fact…