But you wouldn't know that from the FDA-approved food labels, which don't distinguish between dietary and functional fiber. The FDA allows polydextrose to be labeled as a dietary fiber, just the same as whole oats. The same polydextrose products in Canada, which has tighter classification regulations, wouldn't show the fiber content because Health Canada doesn't consider polydextrose to be a dietary fiber. Naturally, food manufacturers in America are taking advantage of this loophole—to the distress of nutrition watchdog groups. "Companies are putting fiber into foods like cookies and ice cream and making people think these are healthy foods, when in fact they should be eating fruits, vegetables, and whole grains. It's dressing up junk food as health food," says Bonnie Liebman, director of nutrition at the Center for Science in the Public Interest in Washington, D.C. "We have no idea if polydextrose has the same benefits as bran. It's deceptive."
For example, Campbell's V8 High Fiber, which Liebman calls "high fibber," claims on its label to offer "20 percent of the recommended daily value" of fiber per 8-ounce glass. As Liebman pointed out in a recent report, the fiber that Campbell's is talking about is maltodextrin, which she says has not been shown to have "any impact on regularity, or any aspect of digestive health." You may have seen the goofy Fiber One Yogurt commercial in which a supermarket employee watches an older woman wolf down yogurt after yogurt. "That's her fourth free sample. ... She's almost had a whole day's worth already," he says, flabbergasted. "And I still can't taste the fiber," the woman replies incredulously. There's a reason for that. The makers of Fiber One Yogurt haven't invented some magically creamy and delicious version of wheat bran. They simply stuffed the yogurt with inulin. A spokeswoman for General Mills, the makers of the yogurt, defends the advertising by pointing to studies showing that inulin suppresses appetite and promotes regularity. Inulin has not been shown to reduce cholesterol levels or lower blood pressure and has a much smaller laxative effect than wheat bran, says Liebman.
Ironically, the rise of these faux-fibers is driven by the greater attention that consumers are paying to nutrition labels. The food companies, in other words, are teaching to the test. Whether it's reducing fat and calories or adding fiber and vitamins, the industry is getting ever more clever at manipulating ingredients of snacks and other treats so that the stats mimic the nutritional data of fruits and vegetables. To be sure, the fortification of foods can facilitate healthier eating. There's not much difference between getting your calcium from milk or from fortified orange juice. (Sometimes, the added nutrients may be beneficial on their own but not when they're inserted into certain foods. The omega-3 fatty acids pumped into eggs, for example, don't cancel out the cholesterol.)
The fiber trend is different and more worrisome. The benefits of "fiber" nutrients like polydextrose are questionable. The makers of Cocoa Pebbles admitted as much when asked about the use and promotion of polydextrose as a dietary fiber. "We are removing the polydextrose ingredient from Pebbles. That is actually happening now," says Scott Monette, a spokesman for Ralcorp, which owns Post cereal brands. He says the company is instead fortifying the cereal with higher doses of vitamin D, which he describes as a "more timely and relevant" nutrient. Just last month, it was reported that vitamin D may protect against common colds and dementia. That should ease my mind next time I rip open a box of Pebbles.