Here’s how to understand carbohydrates
By Mitchell Kanter
Carbohydrates are essential nutrients for players engaging in tournament matches.
In spite of efforts to make food labels more understandable, label reading can still be an intimidating venture.
In the case of carbohydrates, for example, it sometimes seems that you need a doctorate in nutritional biochemistry to decipher the ingredients of a product.
Terms such as corn syrup solids, maltodextrins, high-fructose corn syrup and monosaccharides can make your head spin if you’re not versed in the terminology.
So here’s a brief primer on carbohydrate types and characteristics that can make label reading easier.
Sugar is the leading food additive in the world. It not only serves as a sweetener. It also acts as a tenderizing agent in baked goods, prevents spoilage of products as diverse as jams, jellies and cured meats, and provides structure and texture to sweets.
When most people think of sugar, they think of the white crystalline product we keep in a bowl at home. In fact, there are many substances that are as sweet as or sweeter than table sugar that are commonly used as sugar substitutes by food manufacturers.
Glucose is a monosaccharide (other monosaccharides are fructose and galactose). It often is referred to as grape sugar or dextrose. Glucose is not especially sweet tasting, but it is absorbed rapidly and can be an excellent source of quick energy.
Fructose, on the other hand, is the sweetest of the sugars, but it is absorbed and converted to glucose relatively slowly.
Galactose is of limited importance nutritionally, but it does serve as part of the structure of lactose.
Sucrose, also known as table sugar, is a disaccharide. It is composed of two monosaccharides–glucose and fructose. Sucrose is produced commercially from the juice extracted from sugar cane or beets. When sucrose is eaten, enzymes in the intestine break it down to glucose and fructose. The fructose is eventually converted to glucose in the liver as well .
Additional disaccharides are lactose and maltose.
Lactose is the principal carbohydrate found in milk. An inability to digest lactose, often referred to as lactose intolerance, occurs in many adults. Lactose intolerance is brought about by the failure to produce the enzyme necessary to break down lactose. Symptoms include nausea and diarrhea after ingestion of milk or milk products.
Maltose is not widely present in the foods we eat. It occurs in nature briefly in growing plants and in the malt found in beer.
Corn syrup is manufactured by the enzymatic breakdown of corn starch. The final composition of corn syrup varies depending on the amount of enzymatic breakdown that occurs.
Because fructose is sweeter than sucrose, high-fructose corn syrup has become a popular industrial sweetener. HFCS allows the quantity of sweetener used, and thus the calories and cost of the product, to be lower. HFCS is produced in a manner similar to that of corn syrup; that is, corn starch liquefied and treated with enzymes to produce glucose syrup. Some of the glucose, in turn, is treated with enzymes to produce fructose. The resulting product contains between 42 percent and 90 percent fructose. Most commercial HFCS is either 42 percent or 55 percent fructose. The remainder is glucose.
Maltodextrins also are derivatives of corn starch breakdown. Their chain lengths vary but generally range from three to 20 glucose units in length. By comparison, a typical starch molecule, such as those found in a potato or rice, may contain from 300 to 1,000 or more glucose units strung together.
By convention, most nutritional scientists consider polysaccharides (or complex carbohydrates) to be sugars containing more than 10 monosaccharide units. Therefore, terming maltodextrins “complex carbohydrates” can be misleading. Chemically speaking, maltodextrins are much closer in structure to short-chain, or simple, carbohydrates than they are to longer-chain complex carbohydrates.
Employing this knowledge can make nutrition label reading a bit easier and help make you a more educated consumer.
Mitchell Kanter, PhD, is a senior research scientist at the Gatorade Sports Science Institute.
For more information on health-related topics, please visit the
Gatorade Sports Science Institute
Web site at www.gssiweb.com.