Sugar and Sweeteners

Sweets have been an important part of nearly every culture. The importance to dentistry has been the danger of decay from too many sweets; although it is important to note that current information recognizes cavities can also be caused by other sticky foods and complex carbohydrates like potato chips and crackers.

Sugar typically has referred to table sugar or sucrose, but there are many sugars and sweeteners in common use today.

Simple sugars or simple carbohydrates typically include monosaccharides, and disaccharides (two monosaccharides).
Complex carbohydrates, also known as polysaccharides (composed of many monosaccharides), include starch, cellulose and glycogen.
- Starch, the chief form of carbohydrate stored by plants, is broken down into maltose, then glucose.
- Cellulose makes up plant cell walls. Cellulose is indigestible by humans; however, many animals have digestive bacteria that help them utilize cellulose.
- Glycogen, also known as animal starch, is the chief form of carbohydrate stored in animals. In humans, after carbohydrates have been broken down into simple sugars, the liver will convert fructose and galactose into glucose, which is carried to all the body cells. The liver also converts unused glucose into glycogen, which can be broken down to glucose again when needed.
Alcohol sugars or polyols include sorbitol, mannitol and xylitol. Polyols do not cause decay, although xylitol is the most effective.
Other sweeteners include aspartame, saccharin, acesulfame K, sucralose, and stevia.

Invert sugar is a mixture of glucose and fructose that are levorotatory (turn plane of polarized light to left). Raw sugar and molasses are produced from sugarcane in the process of extracting sucrose. Caramel is obtained from sucrose heated above 356º F.

See the table below for comparisons and information.

Sweetener	Type	Other Names	Notes
glucose	monosaccharide	blood sugar	aldehyde
galactose	monosaccharide		aldehyde, occurs in food only as part of lactose
fructose	monosaccharide	fruit sugar, levulose	ketone
maltose	disaccharide	malt sugar	glucose + glucose
lactose	disaccharide	milk sugar	glucose + galactose
sucrose	disaccharide	table sugar, saccharose, cane sugar	glucose + fructose, product of photosynthesis, used as a preservative in jellies and jams
sorbitol	monosaccharide polyol		60% as sweet as sucrose. Does not break down when heated. Safe in pregnancy. Excessive consumption (more than 50-80 g/day) may have a laxative effect.
mannitol	monosaccharide polyol		70% as sweet as sucrose. Safe in pregnancy. Excessive consumption (more than 20 g/day) may have a laxative effect.
xylitol	monosaccharide polyol		see more, click here
aspartame	amino acids	NutraSweet, Equal	200 times sweeter than sucrose. Made from two amino acids naturally found in foods, phenylalanine and aspartic acid. Cleared for use in pregnancy, except by women with phenylketonuria, or PKU. Aspartame loses sweetness when heated.
saccharin	sulfimide	Sweet ‘n Low	300 times sweeter than sucrose. Not recommended during pregnancy.
acesulfame K	oxathiazinone dioxide	Sunett, Sweet One	200 times sweeter than sucrose. Made from vinegar, is not broken down by body. Structurally related to saccharin. Safe in pregnancy.
sucralose	modified sucrose	Splenda	600 times sweeter than sucrose. Actually made from sugar, but not broken down by body (sucrose molecule in which three of the -OH groups have been replaced by chlorine atoms). Safe for use in pregnancy. Does not break down when heated.
Stevia	diterpene glycosides		300 times sweeter than sucrose. A natural sweetener extracted from the Stevia rebaudiana plant. Technically a dietary supplement because it has not been evaluated or approved by the FDA; however, generally regarded as safe.

For more information on low calorie sweeteners see the Calorie Control Council web site, click here.