While water chestnuts aren’t actually nuts, they are a nutritious and delicious addition to a healthy diet. Here are 5 benefits of eating water chestnuts. Despite being called chestnuts, water chestnuts are not nuts at all. They are aquatic tuber vegetables that grow in marshes, ponds, paddy fields and shallow lakes (1). Water chestnuts are native to Southeast Asia, Southern China, Taiwan, Australia, Africa and many islands in the Indian and Pacific oceans.