Fiber Fights Cancer

Despite earlier reports discounting fiber's role in colorectal cancer prevention, two recent studies say fiber -- from fruits, vegetables, and grains -- may indeed slice the odds of getting the disease. One study, surveying more than half a million people, found a 25 to 40 percent risk reduction from 30 grams of fiber daily (five to seven servings of fruits and vegetables). Fiber in food may be the key, since those earlier studies focused on fiber supplements.

"We can't say fiber is the magic bullet yet, but a diet high in fruits, vegetables, and grains is helpful in colorectal cancer prevention," says Marji McCullough, ScD, senior epidemiologist at the American Cancer Society. Adding too much fiber too soon can cause bloating, warns Heather Greenbaum, a dietitian in New York City. Try adding no more than five grams to your daily diet each week, the equivalent of one pear or a bowl of fiber cereal.