The appearance of 'stealth fiber' in food
Fiber has started to appear on the supermarket shelves in some unusual places. You can now purchase cranberry juice, yogurt and ice cream with 3 or more grams of fiber per serving. It's very strange -- where did all that fiber suddenly come from? After all, cranberry juice and ice cream are typically fiber-free foods.
The secret ingredients are maltodextrin, polydextrose, inulin and oat fiber. Technically they are fibers, but without all the health benefits of naturally occurring fiber. Here's where those fibers come from and what they do.
Maltodextrin is made from starch, most often from corn, potatoes, rice and wheat. The problem is that maltodextrin is digestible and therefore not a fiber. So food companies stepped in and began tinkering around with it to make it resistant to human digestive enzymes. Once we can no longer digest it, then they can classify it as a fiber.
Think about it. They made a food you can't digest!
The problem? There are no good studies showing this "Franken-fiber" provides any of the digestive benefits of naturally occurring fiber.
Polydextrose is made from citric acid, glucose and sorbitol (a sugar alcohol). It's called a synthetic polymer. (Doesn't that sound like something you use to repair a dented car with?) The good news is that polydextrose may help with regularity.
The problem? In higher doses, people report side effects of gas and diarrhea. The side effects are so well known that the Food and Drug Administration requires any food with more than 15 grams of polydextrose per serving to have a label warning consumers that "sensitive individuals may experience a laxative effect from excessive consumption of this product."
Inulin is a powder typically extracted from chicory root. Inulin is a chain of sugars that aren't long enough to be a starch. That means, when it passes through the body, digestive enzymes don't break it down. Once it reaches your intestine, good bacteria eat it up and multiply. That's good. Studies have shown that friendly bacteria in your gut do ferment inulin and the fermented inulin boosts the levels of bifidobacteria, which can reduce the risk of infectious bowl diseases and colon cancer.
The problem? The byproduct of that fermentation process can be bloating, diarrhea and nausea.
Oat fiber is a powder made from the outer layer of the oat kernel. Like inulin, small studies have shown oat fiber can help with regularity.
The problem with all four of these "fake fibers" is that it's unclear if any of them provide the heart healthy benefits of naturally occurring fiber.
Foods that use maltodextrin, polydextrose, inulin and oat fiber may be harmless. But if the majority of fiber you're eating is from these sources, you'll likely be missing out on many of the traditional health benefits of fiber. Those ingredients are high-value marketing tools used to push junk food rather than healthy food additives.
This is your assignment. Count how many grams of fiber you're eating in a day and try to take in your minimum recommended daily allowance. According to the National Academy of Sciences' Institute of Medicine, these are the suggestions:
Men under 50: 38 grams
Men 51 and over: 30 grams
Women under 50: 25 grams
Women 51 and over: 21 grams
Remember, those numbers are the minimums, so taking in more -- as long as you don't exceed your calories for the day -- is fine. Just try to get that fiber from traditional sources such as whole-wheat breads, oatmeal, whole vegetables, beans and whole-grain cereals. Skip the fiber-added fruit juices, yogurts and ice cream.