Courtesy of Suntory Holdings Limited

Pepsi’s latest refresher claims to fend off fat. But is a healthy soda an oxymoron?

“Pepsi Special,” the new drink distributed by Pepsi’s partner in Japan, Suntory Holdings Limited, contains dextrin, a dietary fiber that dissolves in water and is found in fiber supplements such as Benefiber. Eaten appropriately, in fiber-rich foods such as vegetables and fruits, fiber helps to regulate the digestive system, lower cholesterol and may lower the risk of heart disease.

A Suntory news release claims the drink acts by “suppressing the absorption of fat” and can inhibit the rise in triglycerides after a meal, making it, potentially, the first “healthy” soda. Because of these purported health benefits, Pepsi Special has received the label “FOSHU” in Japan, a government designation that stands for “Food for Specified Health Uses.” A Japanese government website states that “FOSHU” products are meant to be consumed “by people who wish to control health conditions, including blood pressure or blood cholesterol.” Spokespeople for Pepsi did not provide more information about the “low-calorie” drink.

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As odd as the fiber-packed cola sounds, however, it’s not the first to debut in Japan. Kirin, the Japanese beer company, launched the country’s first “FOSHU” beverage with dextrin in the spring called Kirin Mets Cola, a sugar-free beverage geared towards “health conscious” men in their 30s.

Is there anything to the dextrin trend? A 2006 study conducted by researchers from the National Institute of Health and Nutrition in Tokyo found that rats fed both dextrin and fat absorbed less fat than the rats who did not eat the fiber. But that research, alas, wasn’t extended to people.

In fact, too much dextrin could make you sick. “Studies of humans ingesting dextrin suggest short-term risks including stomach pain, gas, and bloating,” says Lilian Cheung, editorial director of Nutrition Source, the Harvard School of Public Health’s nutrition website. “The long-term risks have not been studied.”

Dr. Walter Willett, chair of nutrition at the Harvard School of Public Health, added in an email statement: “Unless Pepsi can provide data from controlled studies in humans to the contrary, their claim should be regarded as bogus and deceptive.”

In fact, Pepsi may face challenges if it decides to bring Pepsi Special to the U.S., since the Food and Drug Administration (FDA) tends to frown on such potentially suspect nutrient-boosting of essentially unhealthy products in an attempt to make them healthier. In fact, its regulations specifically discourage such fortifying:

The Food and Drug Administration does not encourage indiscriminate addition of nutrients to foods, nor does it consider it appropriate to fortify fresh produce; meat, poultry, or fish products; sugars; or snack foods such as candies and carbonated beverages.

“You shouldn’t add good things to bad things because that could encourage people to eat something that isn’t healthy for them,” said Michael Jacobson, Executive Director of the Center for Science in the Public Interest (CSPI), a food safety and nutrition consumer advocacy group.

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In the U.S., soda companies have been called out for making exaggerated health claims about their sugary drinks. CSPI recently sued 7UP’s parent company Dr Pepper Snapple Group for making specious health claims about its Cherry Antioxidant, Mixed Berry Antioxidant, and Pomegranate Antioxidant varieties, arguing that drinking a soda with a small amount of Vitamin E is not as healthy as consuming antioxidants from fruits, as the company implied. (The company decided to discontinue the line.) In 2008, the FDA sent a letter to Coca-Cola, arguing that the company “misbranded” its “Diet Coke Plus” because it did not provide enough nutritional information to justify the word “plus.”

So as appealing as it sounds to down a healthy dose of fiber from a can, health experts say it’s probably best to get your daily allotment from food if you want to truly take advantage of the good things fiber can do. “I would assume it’s a soda and treat it that way,” Vandana Sheth, a registered dietitian in the Los Angeles area and spokesperson for The Academy of Nutrition and Dietetics, says about the beverage. “Whole grains, vegetables, barley, beans, lentils have significant positive effects like lowering blood glucose, and some of that will make you feel more full. It is also more satisfying to chew and swallow real food rather than to drink a beverage.”

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Not to mention that guzzling soda and sugary drinks contributes to health problems like obesity, diabetes, heart disease, and may raise blood pressure as well. “Adding a fiber to a drink made from caffeine, caramel coloring, phosphoric acid, sugar, and high fructose corn syrup doesn’t make it healthy,” says Alissa Rumsey, a dietitian at New York Presbyterian Hospital and spokesperson for the New York State Dietetic Association. “If people think they’re going to lose weight by drinking a beverage like this, then they are more likely to drink more soda and therefore consume even more calories.” Which would simply make any of the purported health benefits fizzle out.