Quinoa was first cultivated by farmers in the Andes mountains in Peru and Bolivia between 5,000 and 7,000 years ago. While it's often referred to as a grain, this is a common misconception — quinoa is a broadleaf plant, which makes it a pseudocereal along with other ancient "grains" like amaranth and buckwheat. (Grains like wheat and barley grow as grasses.) Of course, the seeds of all of these plants are used similarly in food: ground into flour, for example, or boiled, like rice, as quinoa's commonly prepared. The leaves of the quinoa plant are also edible, though they're hard to come by except in regions where the crop is grown.
Nutritionally, quinoa is pretty much a no-brainer — it's relatively rich in protein and fiber (8 grams and 5 grams, respectively, per cup), making it more filling and healthful than other gluten-free carb alternatives, like brown rice or potatoes. It's also a good source of magnesium and calcium, which means it's a must for those who don't eat dairy. It has a low glycemic index, so it won't cause blood-sugar spikes like other carbohydrates. Some studies even suggest quinoa is a "complete protein" source — meaning it contains enough of each of the nine amino acids we need for proper nutrition. (Sort of takes one-pot meals to an even simpler level, doesn't it?)
Perhaps unsurprisingly given these nutritional virtues, quinoa has been an important part of many South American cultures for thousands of years. The Incas called it chisiya, or "mother grain," and incorporated it into important religious ceremonies. But, as demand for the now-hip staple has skyrocketed in recent years, critics point out that Bolivians and Peruvians are finding it harder and harder to afford a crop that has played a fundamental role in their societies for millennia. Of course, others argue that the story is much more complicated than we think, pointing to changing cultural attitudes (read: the embrace of Western values and tastes) among younger generations, even producers of the crop seeing it as a valuable export rather than a subsistence product, causing these nations to turn away from quinoa. And, while states like Colorado and Oregon are attempting to grow their own crop, relying domestic quinoa alone probably isn't in the cards for the foreseeable future.
Although the ethical situation behind the quinoa craze is defined by economic and political conditions that are murky at best, its nutritional benefits are hard to argue with. Perhaps the best way to think about quinoa, then, is not as a life-changing everyday "superfood," but as part of a pantheon of options to deliver the nutrients you need. After all, "everything in moderation" means everything — not just the bad stuff.