|
Fiber
Dietary fibers are the indigestible portion of plant foods that move food through the digestive system, absorbing water and easing elimination. Dietary fiber consists of non-starch polysaccharides such as cellulose and many other plant components such as dextrins, inulin, lignin, waxes, chitins, pectins, beta-glucans and oligosaccharides. There are two general categories of fiber - soluble and insoluble. Soluble fibers, which are easily digested, can be divided into three major types: pectins (found in root vegetables, cabbage, apples, whole-wheat bran, and beans); gums (which can be obtained from oatmeal, dried beans, and other legumes); and mucilages (which are synthesized by plant cells and are found in food additives). There are also several types of insoluble fibers. One is cellulose, which can be found in cabbage, peas, apples, root vegetables, whole-wheat flour, beans, bran, and wheat. Another is hemicellulose, which is found in bran, cereals, and whole grains. Lignan, most abundantly found in flaxseed, is a phytochemical that works very much like an insoluble fiber. Fiber is actually classified as a carbohydrate; in the U.S. the total carbohydrates listed on a food label will include dietary fiber, although the fiber is listed separately.
|
|
Antioxidants
Antioxidants are compounds that may protect cells from damage from free radicals. Exposure to various environmental factors, including tobacco smoke and radiation, can also lead to free radical formation. In humans, the most common form of free radicals is oxygen. When an oxygen molecule (O2) becomes electrically charged or "radicalized" it tries to steal electrons from other molecules, causing damage to DNA and other molecules. Over time, such damage may become irreversible and lead to disease including cancer. Antioxidants interact with and stabilize free radicals and may prevent some of the damage free radicals otherwise might cause. Examples of antioxidants include anthocyanins, beta-carotene, lycopene, astaxanthin and many others. Click here for the ORAC of Selected Foods 2007.
|