Quinoa was important to the diet of pre-Columbian Andean civilizations.Today, people appreciate quinoa for its nutritional value. Quinoa has been called a superfood. Protein content is very high for a cereal/pseudo-cereal (14% by mass), yet not as high as most beans and legumes. Quinoa's protein content per 100 calories is higher than brown rice, potatoes, barley and millet, but is less than wild rice and oats.Nutritional evaluations of quinoa indicate that it is a source of complete protein. Furthermore, it is a good source of dietary fiber and phosphorus and is high in magnesium and iron. Quinoa is also a source of calcium, and thus is useful for vegans and those who are lactose intolerant. Quinoa is gluten-free and considered easy to digest. Because of all these characteristics, quinoa is being considered a possible crop in NASA's Controlled Ecological Life Support System for long-duration human occupied spaceflights.