The yacón is closely related to Jerusalem artichokes and sunflowers, producing large, sweet-flavoured, tuberous roots weighing up to a kilogram. Yacón was almost unknown outside its original native area until the early 21st century, but word spread that it had potential for lowering glucose levels in the blood and its popularity expanded. The plant is now grown in many areas of the world and has a niche market in health food stores.
Yacón syrup is considered to have high antioxidant properties, and yacón tea can be made from the leaves, which also contain quantities of phenol antioxidants that help to reduce blood sugar but do not affect insulin production.
Yacón is valuable for both diabetics and dieters, as the tubers are made up mostly of an indigestible fructose polysaccharide called fructo-oligosaccharide. This substance has a sweet taste, and can be used as a food additive or sweetener, but it does not get absorbed in the human gastro-intestinal tract, and therefore passes on very few calories.
Fructo-oligosaccharides also have prebiotic qualities, meaning that they stimulate the growth and activity of micro-organisms, in this case the beneficial bacteria which work in the gastro-intestinal tract to aid digestion and enhance colon health.