Sweet potatoes boost immune function, increasing the ability to fight infections, especially viral infections. They help maintain healthy lining of the digestive tract, respiratory tract and skin. They are known to improve retinal function, particularly night vision. They are shown to modulate and even improve blood sugar regulation. They contain adiponectin, a protein hormone produced by fat cells that modulates insulin metabolism. Sweet potatoes also contain healthy antioxidants, including Vitamin A and carotenoids.