It seems that your mom's nagging you to eat your fruits and vegetables was justified. Getting your "roughage" is important. Roughage, what we now refer to as fiber, is the indigestible portion of food that travels through the digestive system virtually intact. While dietary fiber has no nutritional value, it can have a profound impact on health, including lowering the risk for certain types of cancer, lowering blood cholesterol levels and minimizing the complications of diabetes. In addition, it may even aid appetite control.
Fiber can be classified into two categories--soluble and insoluble, depending on its ability to bond with water molecules. The loosely knit chemical bonds of fiber molecules allow them to pick up water molecules in the course of their journey through the digestive system. "Soluble" fiber molecules readily accept and retain water, whereas "insoluble" fibers are more rigid and crystalline in structure and have few available bonds for water molecules.
Not only can fiber bond with water, but fiber molecules also bond with substances such as hormones, bile acids and potential carcinogens. Because of this, fiber plays an important role in preventing the following:
No one agrees on exactly how much fiber is needed for good health. The American Dietetic Association recommends 20-35 grams of fiber a day, while the National Cancer Institute advises consuming 25-30 grams.
To increase fiber intake, it is best to do so by changing your diet, not relying on supplements. A reasonable goal is adding one to two grams of fiber a day. Also, remember that fiber absorbs water, so increase your fluid intake to at least eight eight-ounce glasses a day. The chart below gives examples of foods high in dietary fiber.
Navy, kidney, pinto and lima beans
Skins of fruits and vegetables
Raspberries and strawberries
Sesame and poppy seeds
Navy, pinto and lima beans
Fruits and vegetables
Nancy Anderson is coordinator of the Emory HeartWise Program. The publication of the Wellness column is coordinated by the Seretean Center for Health Promotion.