For most of the three decades that Ancient Harvest has been selling quinoa, business was relatively tame as it supplied boutique supermarkets and health-food stores.

That changed abruptly about five years ago. Major retailers started seeking out the brand—and sales took off.

Today, Ancient Harvest quinoa products—which now include quinoa linguine, quinoa mac and cheese, and quinoa hot cereal flakes, among other iterations—are sold at general retailers like Walgreens and Piggly Wiggly. Quinoa Corp., the brand’s owner, expects sales this year to double from their 2012 level, says Chief Executive Blake Waltrip, declining to disclose actual figures.

Early on, “we were a small company that had no money to spend on marketing. We had to count on consumers to come across this obscure grain,” he said. Now, retailers all “want to be part of the trend.”

Quinoa is a titan of the so-called superfoods, a loosely defined collection of produce that advocates claim have extraordinary nutritional benefits, whether it be high levels of antioxidants or omega-3s. Quinoa is lauded for its protein, fiber, iron and other minerals.

In roughly the past decade, foods adorned with the superfoods title have exploded in popularity, changing eating habits and shaking up food companies. The group includes basics long part of the American diet, like blueberries, collard greens and avocados, but also exotic newcomers like quinoa, chia seeds, açaí berries and amaranth, a grain. Amazon.com lists more than 700 books with “superfood” in the title, including “Superfoods for Dummies.”

No individual or single group spawned superfoods’ current esteem. They owe their success to a mélange of curious consumers, nutrition pundits, cooking gurus and food companies zealous to exploit the newest trends.

Quinoa also has gotten a boost from the gluten-free boom that took hold late last decade. Though technically not a grain, its seeds can be served like rice or made into flour for pasta. But it doesn’t contain the gluten proteins that many consumers now are trying to avoid.

“Quinoa is a perfect collision of trends,” says Jennifer Baum, president of Bullfrog + Baum, a New York marketing firm that specializes in the food and hospitality industries.

U.S. imports of quinoa—grown mainly in the Andes mountains of South America—soared to 14.2 million pounds last year from 1.6 million pounds in 2007, according to trade-data provider Datamyne Inc. Its price more than doubled in that time, to $7.56 a pound from about $3.50.

The term superfood began gaining currency in the late 1980s, and gradually moved toward the mainstream. The growth of natural grocers like Whole Foods Markets Inc. WFM +0.58% —which went from one store in 1980 to 357 U.S. stores as of April—helped propel the trend by making such foods more visible and available.

Kathleen Bagley Formidoni, a 47-year-old from Santa Barbara, Calif., said she started eating items like kale and chia seeds about five years ago on the recommendation of yoga partners. “I feel healthier and my brain is clearer,” she said. Lately she has considered trying baobab powder, from a tree native to Africa, the Middle East and Australia.

Health experts generally say that most items dubbed superfoods are relatively nutritious. But some dietitians say the designation is more about marketing than nourishment. And some in Congress and elsewhere have raised concerns about the marketing of supplements billed as superfoods, especially when they are touted for things like fending off cancer.

“I have mixed feeling about superfoods. On one hand they are good for you, but they get a lot of buzz because we want to have something to talk about,” said Kerri-Ann Jennings, a registered dietitian in Burlington, Vt. Superfoods often command higher prices than humdrum items like barley and frozen broccoli, she said, but those items are “going to be way better for your diet than buying açaí berries and sprinkling them on your sugar-laden cereal.”
Quinoa, a staple of Andean diets for several thousand years, got its first real introduction into the U.S. when a trio of Colorado men founded Ancient Harvest in 1983 and began importing it and promoting it for its high protein content and culinary versatility.

Others jumped on the bandwagon. ConAgra Foods Inc., one of the biggest food producers in the U.S., in 2007 launched a line of products called Ancient Grains that featured quinoa. Mehmet Oz, the television health pundit known as Dr. Oz, endorsed quinoa. So did the United Nations, whose Food and Agriculture Organization declared 2013 the “international year of quinoa,” promoting its attributes for fighting world hunger.

Some assistance was less predictable. AB InBev’s Bud Light ran a mocking television ad last year with a fan of the Philadelphia Eagles football team stuck grilling quinoa burgers while tailgating. The fan mispronounces it “QUEE-no,” and says it tastes like “a dirty old tree branch.” (It is pronounced “keen-wah.”) But the ad cemented quinoa’s status in the zeitgeist.

“Nobody says ‘quinn-NO-ah’ anymore,” said Cynthia Harriman, director of food and nutrition strategies at Whole Grains Council, a nonprofit natural-food group.

Like many of the more obscure superfoods, quinoa isn’t native to the U.S., where efforts at large-scale cultivation of it have struggled. Most quinoa still is grown in Bolivia and Peru, where it has been a boon to farmers of the crop. But rising exports mean locals now have to pay higher prices for one of their basic foods.

Juan Luis Reus, chief executive of Peru’s Trade, Tourism and Investment office in Washington, D.C., says supplies are sufficient for now, and notes that increased tax revenue from growing quinoa sales abroad helps pay for infrastructure and other communal goods. But if demand keeps surging and sucks up more of Peru’s quinoa supply, he says, “that could be a concern.”