 It's National Blueberry Month, and health experts say blueberries are one of the best snacks you can get your hands on. Blueberries are a great source of fiber, antioxidants, and they're one of the lowest sugar fruits out there, making them one of the best options for us to snack on. Registered dietician Alexis Supan says eating foods high in antioxidants allows your body to fight off free radicals. Rich in vitamin C and vitamin K, blueberries help your immune system and help to maintain strong bones.