Supplemental Fiber Is Healthy
TRUE: Foods with added fiber don't necessarily provide the benefits you might expect. Inulin, for example, a soluble fiber extracted from chicory root, can be found in products like Fiber One bars. In addition to boosting fiber content, it's also commonly used to replace fat. Inulin is known as a prebiotic, which means it promotes the growth of healthy bacteria in your gut. That's good, of course. "But," says Slavin, "inulin doesn't have the same cholesterol-lowering effect as the fiber found in oat bran."
Food Companies Are Jumping on the Fiber BandwagonDUH: In 2007, the FDA declared that polydextrose can be called fiber. Poly-what? Polydextrose is made from glucose, sorbitol (a sugar alcohol), and citric acid. It's what puts the fiber in Fruity Pebbles (not actual pebbles). Polydextrose received FDA approval because it mimics some attributes of dietary fiber: It isn't absorbed in the small intestine, and it increases stool weight. Polydextrose mainly bulks up foods so they're not as high in calories. However, there's no research to prove that polydextrose is as beneficial as the fiber found in whole foods. Discover 11 other secrets the food industry doesn't want you to know.
Fiber Helps Prevent Colon Cancer
MAYBE: This idea arose in the 1960s when it was noted that fiber-scarfing Ugandans rarely developed colon cancer. But nearly five decades later, it still hasn't been proven.
In 1999, Harvard researchers found no link between dietary fiber intake and colon cancer. But a European study that tracked more than a half million people correlated a high-fiber diet with up to a 40 percent reduced risk of colorectal cancer. Then a 2005 review in the Journal of the American Medical Association found that people who ate the same amount of fiber as those in the European study didn't experience any benefit. The American Institute for Cancer Research calls protection "probable." This controversy aside, high-fiber diets are associated with preventing many chronic diseases, so it's smart to boost your intake, says Arthur Schatzkin, M.D., Dr.P.H., of the National Cancer Institute. Prevent disease and add years to your life with these secret age erasers.
You Need 38 Grams of Fiber a Day
FALSE: That's the recommendation from the Institute of Medicine. Scientists there crunched data from three studies and squeezed out the number 38 in 2005. It equals 9 apples, or 12 bowls of instant oatmeal. (Most people eat about 15 grams of fiber daily.) The studies found a correlation between high fiber intake and lower incidence of heart disease. But none of the high-fiber-eating groups in those studies averaged as high as 38 grams, and, in fact, people saw maximum benefits with a daily gram intake averaging from the high 20s to the low 30s. Also, it's worth noting that these studies don't show cause and effect, and that unless you're taking a supplement, it's hard even for those who eat the healthiest of diets to consume 38 grams of fiber. It's fine to shoot for that amount, but you're certainly not failing if you don't meet it.
This Is Complicated
FALSE: A simple strategy: Eat sensibly—check out the 125 best foods in your supermarket. Favor whole, unprocessed foods. Make sure the carbs you eat are fiber-rich—this means produce, legumes, and whole grains—to help slow the absorption of sugar into your bloodstream. "The more carbohydrates you eat, the more fiber becomes important to help minimize the wide fluctuations in blood-sugar levels," says Jeff Volek, Ph.D., R.D., a nutrition researcher at the University of Connecticut.
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