chapter 4- The Carbohydrates

Carbohydrates

compounds composed of single or multiple sugars. The name means "carbon and water," and a chemical shorthand for carbohydrate is CHO, signifying carbon (C), hydrogen (H), and oxygen (O).

prediabetes

condition in which blood glucose levels are higher than normal but not high enough to be diagnosed as diabetes; a major risk factor for diabetes and cardiovascular diseases.

dental caries

decay of the teeth (caries means "rottenness"). Also called cavities.

disaccharides

pairs of single sugars linked together (di means "two").

endosperm

the bulk of the edible part of a grain, the starchy part.

resistant starch

the fraction of starch in a food that is digested slowly, or not at all, by human enzymes.

germ

the nutrient-rich inner part of a grain.

insulin

a hormone secreted by the pancreas in response to a high blood glucose concentration. It assists cells in drawing glucose from the blood.

starch

a plant polysaccharide composed of glucose. After cooking, starch is highly digestible by human beings; raw starch often resists digestion.

glucose

a single sugar used in both plant and animal tissues for energy; sometimes known as blood sugar or dextrose.

ketone bodies

acidic, water-soluble compounds that arise during the breakdown of fat when carbohydrate is not available

Hypoglycemia

an abnormally low blood glucose concentration, often accompanied by symptoms such as anxiety, rapid heartbeat, and sweating.

ketosis

an undesirable high concentration of ketone bodies, such as acetone, in the blood or urine

polysaccharides

another term for complex carbohydrates; compounds composed of long strands of glucose units linked together (poly means "many"). Also called complex carbohydrates.

brown bread

bread containing ingredients such as molasses that lend a brown color; may be made with any kind of flour, including white flour.

wheat bread

bread made with any wheat flour, including refined enriched white flour.

fasting plasma glucose test

a blood test that measures current blood glucose in a person who has not eaten or consumed caloric beverages for at least 8 hours; the test can detect both diabetes and prediabetes. Plasma is the fluid part of whole blood.

HbA1c test

a blood test that measures hemoglobin molecules with glucose attached to them (Hb stands for hemoglobin). The test reflects blood glucose control over the previous few months. Also called glycosylated hemoglobin test, or A1C test.

insulin resistance

a condition in which a normal or high level of circulating insulin produces a less-than-normal response in muscle, liver, and adipose tissues; thought to be a metabolic consequence of obesity.

sucrose

a disaccharide composed of glucose and fructose; sometimes known as table, beet, or cane sugar and, often, as simply sugar.

lactose

a disaccharide composed of glucose and galactose; sometimes known as milk sugar (lact means "milk"; ose means "sugar").

maltose

a disaccharide composed of two glucose units; sometimes known as malt sugar.

autoimmune disorder

a disease in which the body develops antibodies to its own proteins and then proceeds to destroy cells containing these proteins. Examples are type 1 diabetes and lupus.

dialysis

a medical treatment for failing kidneys in which a person's blood is circulated through a machine that filters out toxins and wastes and returns cleansed blood to the body. Also called hemodialysis.

galactose

a monosaccharide; part of the disaccharide lactose (milk sugar).

fructose

a monosaccharide; sometimes known as fruit sugar (fruct means "fruit"; ose means "sugar").

glycemic index (GI)

a ranking of foods according to their potential for raising blood glucose relative to a standard food such as glucose.

multi-grain

a term used on food labels to indicate a food made with more than one kind of grain. Not an indicator of a whole-grain food.

white wheat

a wheat variety developed to be paler in color than common red wheat (most familiar flours are made from red wheat). White wheat is similar to red wheat in carbohydrate, protein, and other nutrients, but it lacks the dark and bitter, but potentially beneficial, phytochemicals of red wheat.

high-fructose corn syrup (HFCS)

a widely used commercial caloric sweetener made by adding enzymes to cornstarch to convert a portion of its glucose molecules into sweet-tasting fructose.

soluble fibers

food components that readily dissolve in water and often impart gummy or gel-like characteristics to foods. An example is pectin from fruit, which is used to thicken jellies.

whole grains

grains or foods made from them that contain all the essential parts and naturally occurring nutrients of the entire grain seed (except the inedible husk).

viscous

having a sticky, gummy, or gel-like consistency that flows relatively slowly.

lactose intolerant

impaired ability to digest lactose due to reduced amounts of the enzyme lactase.

appendicitis

inflammation and/or infection of the appendix, a sac protruding from the intestine.

complex carbohydrates

long chains of sugar units arranged to form starch or fiber; also called polysaccharides.

glycemic load (GL)

mathematical expression of both the glycemic index and the carbohydrate content of a food, meal, or diet.

diabetes

metabolic diseases characterized by elevated blood glucose and inadequate or ineffective insulin, which impair a person's ability to regulate blood glucose. The technical name is diabetes mellitus (mellitus means "honey-sweet" in Latin, referring to sugar in the urine).

chelating agents

molecules that attract or bind with other molecules and are therefore useful in either preventing or promoting movement of substances from place to place.

stone ground

refers to a milling process using limestone to grind any grain, including refined grains, into flour.

enriched

refers to the addition of nutrients to a refined food product. As defined by U.S. law, these terms mean that specified levels of thiamin, riboflavin, niacin, folate, and iron have been added to refined grains and grain products. The terms enriched and fortified can refer to the addition of more nutrients than just these five; read the label.

refined

refers to the process by which the coarse parts of food products are removed. For example, the refining of wheat into white enriched flour involves removing three of the four parts of the kernel—the chaff, the bran, and the germ—leaving only the endosperm, composed mainly of starch and a little protein.

sugars

simple carbohydrates; that is, molecules of either single sugar units or pairs of those sugar units bonded together. By common usage, sugar most often refers to sucrose

monosaccharide

single sugar units (mono means "one"; saccharide means "sugar unit").

granules

small grains. Starch granules are packages of starch molecules. Various plant species make starch granules of varying shapes.

sugar alcohols

sugarlike compounds in the chemical family alcohol derived from fruits or manufactured from sugar dextrose or other carbohydrates; sugar alcohols are absorbed more slowly than sugars, are metabolized differently, and do not elevate the risk of dental caries. Also called polyols.

added sugars

sugars and syrups added to a food for any purpose, such as to add sweetness or bulk or to aid in browning (baked goods). Also called carbohydrate sweeteners, they include concentrated fruit juice, glucose, fructose, high-fructose corn syrup, sucrose, and other sweet carbohydrates.

naturally occurring sugars

sugars that are not added to a food but are present as its original constituents, such as the sugars of fruit or milk.

simple carbohydrates

sugars, including both single sugar units and linked pairs of sugar units. The basic sugar unit is a molecule containing six carbon atoms, together with oxygen and hydrogen atoms.

nonnutritive sweeteners

sweet-tasting synthetic or natural food additives that offer sweet flavor but with negligible or no calories per serving; also called artificial sweeteners, intense sweeteners, noncaloric sweeteners, and very low-calorie sweeteners.

protein-sparing action

the action of carbohydrate and fat in providing energy that allows protein to be used for purposes it alone can serve.

fermentation

the anaerobic (without oxygen) breakdown of carbohydrates by microorganisms that releases small organic compounds along with carbon dioxide and energy.

chlorophyll

the green pigment of plants that captures energy from sunlight for use in photosynthesis.

fibers

the indigestible parts of plant foods, largely nonstarch polysaccharides that are not digested by human digestive enzymes, although some are digested by resident bacteria of the colon. Fibers include cellulose, hemicelluloses, pectins, gums, mucilages, and a few nonpolysaccharides such as lignin.

lactase

the intestinal enzyme that splits the disaccharide lactose to monosaccharides during digestion

husk

the outer, inedible part of a grain.

photosynthesis

the process by which green plants make carbohydrates from carbon dioxide and water using the green pigment chlorophyll to capture the sun's energy (photo means "light"; synthesis means "making").

bran

the protective fibrous coating around a grain; the chief fiber donator of a grain.

insoluble fibers

the tough, fibrous structures of fruits, vegetables, and grains; indigestible food components that do not dissolve in water.

type 2 diabetes

the type of diabetes in which the pancreas makes plenty of insulin but the body's cells resist insulin's action; often diagnosed in adulthood. Formerly called adult-onset or non-insulin-dependent diabetes.

type 1 diabetes

the type of diabetes in which the pancreas produces no or very little insulin; often diagnosed in childhood, although some cases arise in adulthood. Formerly called juvenile-onset or insulin-dependent diabetes.

diverticula

sacs or pouches that balloon out of the intestinal wall, caused by weakening of the muscle layers that encase the intestine. The painful inflammation of one or more of the diverticula is known as diverticulitis.