Coke exec says artificial sweeteners questioned

• Coke executive says consumers have concerns about Diet Coke ingredients
• Diet soda sales took a serious hit industry-wide last year
• Both Coke and Pepsi working on natural diet sweeteners

Diet Coke is feeling the pinch as consumers sour on artificial sweeteners.

In a candid admission, a senior Coca-Cola official conceded that Tuesday in a conference call with top industry analysts.

Diet Coke — and an array of other food and beverage diet products — "are under a bit of pressure as people are questioning ingredients (and) ingredient safety," says Steve Cahillane, president of Coca-Cola Americas, which includes Coke's North American and Latin American business.

"There are headwinds that we're facing," Cahillane said. "This is just one of them." He went on to say that Coca-Cola believes "very strongly in the future of Diet Coke," which is the No. 2-selling soft-drink, after regular Coca-Cola, in the U.S. Even then, he said, Coke is about twice the size of Diet Coke.

For Coca-Cola, it's gut-check time. For years, consumers concerned with healthier beverages have been cutting-back on sugary, carbonated soft drinks. Now, a growing movement is afoot to also cut back on diet soft drinks — because of the questionable affects of their sweeteners.

That's why, earlier this summer, Coke ran a national print ad assuring consumers that the sweetener it uses in some of its diet beverages is safe. "The safety of aspartame is supported by more than 200 studies over the last 40 years," the ad assured consumers.

This action followed 2012 reports that showed diet soft drink sales falling faster than non-diet soft drinks. Coke sales fell 1% last year, while Diet Coke sales fell 3%, reports Beverage Digest. At the same time, Pepsi sales fell 3.4%, while Diet Pepsi sales dropped 6.2%.

Never mind that the Food and Drug Administration says that aspartame is safe.

Even though aspartame has been proven to be safe, aspartame's "gotten dinged a bit recently" because of it, says John Sicher, editor of Beverage Digest. That's a key reason both Coke and Pepsi are working on new, natural diet sweeteners, he says, "and I think we'll see some major innovation in 2014 and 2015."

Soda industry executives are keenly aware of the declines in diet soda. Earlier this year, PepsiCo CEO Indra Nooyi told an investor conference that while consumers love the bubbles, the caffeine and the taste of cola, they don't like the sugar levels, "and recently, they don't like artificial sweeteners."

At the same time, Dr Pepper Snapple Group CEO Larry Young said, in a conference call that "people have concerns about artificial sweeteners."

Few folks like artificial sweeteners any less than Dr. Janet Starr Hull, an environmental toxicologist and author of Sweet Poison, a book about what she claims to be the dangers of aspartame.

She says that aspartame in soft drinks almost killed her. "Aspartame should be taken off the market — and it should never have been put on the market," she says.

But when her book was published in 1998, that message fell on mostly deaf ears. Now, she says, thanks to social media, "the message is reaching enough people, that the soda makers are finally being held accountable."

That's why she's writing yet another book on the topic: The Sweetener Wars.