Sweet potatoes’ reputation as a so-called superfood seems to be on the rise, and not just as a low-carbohydrate, high-fiber food source.

Now, they have the backing of the American Heart Association, which in November 2010 certified fresh-market sweet potatoes to bear the association’s heart-check mark.

“I think sweet potatoes are a well-positioned nutritionally, anyway, but with this getting certified for use of that heart check mark, it adds a little to what we’re doing,” said Charles Walker, executive secretary of the Columbia, S.C.-based U.S. Sweet Potato Council.

“They have consumer surveys that say seeing that heart check mark on a product or package, people that are looking for healthy foods kind of use that check mark as a guideline in making heart-healthy purchases.”

The process of getting sweet potatoes certified by the heart association goes back to 2006, Walker said.

“They’re making some effort, I believe, to get more produce items certified with the heart check mark,” he said.

Achieving the heart association’s endorsement is the latest in a string of positive developments for marketing sweet potatoes as a high-nutrition food, marketers said, citing the first big bump during the Atkins and South Beach diet crazes of several years ago.

“We believe that we have a good, strong nutrition message, and we are developing various strategies for implementing a very strong nutrition message in our marketing efforts,” said Sue Johnson-Langdon, executive director of the Smithfield-based North Carolina SweetPotato Commission.

The health message has helped sweet potatoes climb to a new marketing level, said Sandi Kronick, chief executive officer of Eastern Carolina Organics, Pittsboro, N.C.

“They’re still getting a fair amount of press, as far as being a very exciting item that’s kind of a Southern food that has kind of made its way and established itself in the broad culinary world,” she said.

Benny Graves, executive director of the Vardaman-based Mississippi Sweet Potato Council, said the heart-check certification is a major plus for sweet potatoes.

“The nutritional value of the sweet potato is well known,” Graves said.

“Anybody who’s serious about their diet has already picked up on that. In fact, the new processed product has high nutrition. Betty Crocker has a mashed sweet potato mix now.”

Other suppliers and marketers note the other dietary pluses that sweet potatoes carry.

“The low-carb part of that is it’s a complex carbohydrate and the low glycemic is where it’s being pushed now,” said George Wooten, owner of Wayne E. Bailey Produce Co., Chadbourn, N.C.

“If somebody goes on a low-glycemic index, white potatoes are taboo, period, because it spikes your blood sugar so high. Sweet potatoes fit that diet.”

The product gets regular plugs in the mass media, Wooten said, citing the “Dr. Oz Show” as having listed sweet potatoes as one of five superfoods.

Indeed, the show’s blog makes mention of it:

“The women of Okinawa, Japan (who also happen to be the world’s longest-living ladies), enjoy a purple sweet potato they call Imo every day for breakfast, lunch and dinner. Rich in beta-carotene and boasting 150 percent more antioxidants than blueberries, this easy-to-make treat can be simply incorporated into an American diet. And, if you can’t find Imo specifically, our orange sweet potatoes pack a similarly healthful wallop.”

Other media have picked up and carried the message, said Thomas Joyner, president of Nash Produce, Nashville, N.C.

“They’ve been ranked in the top 25 food items in magazines, so the trend continues for sweet potatoes as a health food,” he said.

The results have been fantastic, said Faye Bone, co-owner of Royce C. Bone Farms, Nashville.

“The fact that they are no longer just a holiday food and the growth of sweet potatoes in steakhouses have helped out a lot,” Bone said.

Stewart Precythe, president and chief executive officer of Faison, N.C.-based Southern Produce Distributors Inc., agreed.

“It just has all the nutritional value you need. You can live on them,” he said. “How many foods can say that?”