Jerusalem artichokes, like globe artichokes, are a rich source of inulin. Inulin is a polysaccharide, or starch, that is handled by the body differently from other sugars. In fact, inulin is not utilized by the body for energy metabolism. This makes Jerusalem artichokes extremely beneficial to diabetics. In fact, Jerusalem artichoke polysaccharides have actually been shown to improve blood sugar control. Since the body does not utilize the primary carbohydrate of Jerusalem artichoke, the calorie content is virtually nil, only 7 calories per 100 grams (roughly 31/2 ounces).
Jerusalem artichokes may also have some immune-enhancing activity, as inulin also has the ability to enhance a component of our immune system known as complement. Complement is responsible for increasing host defense mechanisms, such as neutralization of viruses, destruction of bacteria, and increased movement of white blood cells (neutrophils, monocytes, eosinophils, and lymphocytes) to areas of infection. Many medicinal plants, such as echinacea and burdock, owe much of their immune-enhancing effects to inulin. Jerusalem artichoke is one of the richest sources of inulin available.