Health Effects and Recommended Intakes of Sugars

Ever since people first discovered honey and dates, they have enjoyed the sweetness of sugars. In the United States, the natural sugars of milk, fruits, vegetables, and grains account for about half of the sugar intake; the other half consists of sugars that have been refined and added to foods for a variety of purposes. Added sug-

lossary of Sugars brown sugar: refined white sugar crystals to which manufacturers have added molasses syrup with natural flavor and color; 91 to 96 percent pure sucrose.

confectioners' sugar: finely powdered sucrose; 99.9 percent pure.

corn sweeteners: corn syrup and sugars derived from corn.

corn syrup: a syrup produced by the action of enzymes on cornstarch; contains mostly glucose. See also high-fructose corn syrup (HFCS).

dextrose: an older name for glucose.

granulated sugar: crystalline sucrose; 99.9 percent pure.

high-fructose corn syrup (HFCS): a corn-syrup sweetener made especially for use in processed foods and beverages, where it is the predominant sweetener. HFCS is mostly fructose; glucose makes up the balance.

honey: sugar (mostly sucrose) formed from nectar gathered by bees. An enzyme splits the sucrose into glucose and fructose. Composition and flavor vary, but honey always contains a mixture of sucrose, fructose, and glucose.

invert sugar: a mixture of glucose and fructose formed by the hydrolysis of sucrose in a chemical process; sold only in liquid form and sweeter than sucrose. Invert sugar is used as a food additive to help preserve freshness and prevent shrinkage.

levulose: an older name for fructose.

maple sugar: a sugar (mostly sucrose) purified from the concentrated sap of the sugar maple tree.

molasses: the thick brown syrup produced during sugar refining. Molasses retains residual sugar and other by-products and a few minerals; blackstrap molasses contains significant amounts of calcium and iron—the iron comes from the machinery used to process the sugar.

raw sugar: the first crop of crystals harvested during sugar processing. Raw sugar cannot be sold in the United States because it contains too much filth (dirt, insect fragments, and the like). Sugar sold as "raw sugar" domestically has actually gone through over half of the refining steps.

turbinado (ter-bih-NOD-oh) sugar: sugar produced using the same refining process as white sugar, but without the bleaching and anti-caking treatment; traces of molasses give turbinado its sandy color.

white sugar: pure sucrose or "table sugar," produced by dissolving, concentrating, and recrystallizing raw sugar.

ars assume various names: sucrose, invert sugar, com sugar, com syrups and solids, high-fructose corn syrup, and honey (see the glossary above).

The use of sweeteners in food manufacturing has risen steadily over the past two decades, reaching a record high of 139 pounds per person per year. This estimate represents all sweeteners used in the marketing system, including sugar lost or wasted, such as in the brine of sweet pickles or in jams or bakery goods that spoil before they are eaten. It also includes sugar used in pet foods and in fermentation. Estimates of intake indicate that on the average, each person consumes about 45 pounds of added sugar per year.22 As a percentage of daily energy intake, this amount is roughly equivalent to current recommendations that concentrated sugars contribute no more than about 10 percent of energy intake.

Health Effects of Sugars

In moderate amounts (similar to current consumption levels), sugars add pleasure to meals without harming health. In excess, however, they can be detrimental in two ways. One, sugars can contribute to nutrient deficiencies by supplying energy (kcalories) without providing nutrients, and so dietary guidelines caution people against eating large quantities. Two, sugars contribute to tooth decay, and so dietary guidelines caution people against eating frequent snacks containing sugars and starches.

• Nutrient Deficiencies • Foods that contain lots of added sugar such as cakes, candies, and colas deliver glucose and energy with few, if any, other nutrients— they are called empty-kcalorie foods. By comparison, foods such as grains, vegetables, and fruits that contain some natural sugars and lots of starches and fibers deliver their glucose and energy along with protein, vitamins, and minerals.

A person spending 200 kcalories of a day's energy allowance on a 16-ounce cola gets little of value for those kcaloric "dollars." In contrast, a person using 200 kcalories on three slices of whole-wheat bread gets 9 grams of protein, 6 grams of fiber, plus several of the B vitamins with those kcalories. For the person who wants

As an additive, sugar:

  • Enhances flavor.
  • Supplies texture and color to baked goods.
  • Provides fuel for fermentation, causing bread to rise or producing alcohol.
  • Acts as a bulking agent in ice cream and baked goods.
  • Acts as a preservative in jams.
  • Balances the acidity of tomato- and vinegar-based products.

empty-kcalorie food: a popular term used to denote foods that contribute energy but are lacking protein, vitamins, and minerals. Empty-kcalorie foods are low-nutrient density foods. The most notorious empty-kcalorie foods are sugar, fat, and alcohol.

1 tsp honey = 22 kcal. 1 tsp sugar = 16 kcal.
You receive the same sugars from an orange as from honey, but the packaging makes a big nutrition difference.

dental caries: decay of teeth. • caries = rottenness

To prevent dental caries:

  • Eat sugary foods with meals.
  • Limit between-meal snacks containing sugars and starches.
  • Brush and floss teeth regularly.
  • If brushing and flossing are not possible, at least rinse with water.

plaque, dental: a gummy mass of bacteria that grows on teeth and can lead to dental caries and gum disease.

something sweet, perhaps a reasonable compromise would be to have two slices of bread with a teaspoon of jam on each. The amount of sugar a person can afford depends on how many kcalories are available beyond those needed to deliver indispensable vitamins and minerals.

With careful food selections, a person can obtain all the needed nutrients within an allowance of about 1500 kcalories. Some people have more generous energy allowances with which to "purchase" nutrients. For example, an active teenage boy may need as many as 4000 kcalories a day. If he eats mostly nutritious foods, then the "empty kcalories" of cola beverages may be an acceptable addition to his diet. On the other hand, an inactive older woman who is limited to fewer than 1500 kcalories a day cannot afford any but the most nutrient-dense foods.

Some people believe that because honey is a natural food, it is nutritious—or, at least, more nutritious than sugar. A look at their chemical structures reveals the truth. Honey, like table sugar, contains glucose and fructose. The primary difference is that in table sugar the two monosaccharides are bonded together, whereas in honey some of them are free. Whether a person eats monosaccharides individually, as in honey, or linked together, as in table sugar, they end up the same way in the body: as glucose and fructose.

Honey does contain a few vitamins and minerals, but not many, as Table 4-2 shows. Honey is denser than crystalline sugar, too, so it provides more energy per spoon.

This is not to say that all sugar sources are alike, for some are more nutritious than others. Consider a fruit, say, an orange. The fruit may give you the same amounts of fructose and glucose and the same number of kcalories as a dose of sugar or honey, but the packaging is more valuable nutritionally. The fruit's sugars arrive in the body diluted in a large volume of water, packaged in fiber, and mixed with valuable minerals and vitamins.

As these comparisons illustrate, the significant difference between sugar sources is not between "natural" honey and "purified" sugar but between concentrated sweets and the dilute, naturally occurring sugars that sweeten foods. You can suspect an exaggerated nutrition claim when someone asserts that one product is more nutritious than another because it contains honey.

Sugar can contribute to nutrient deficiencies only by displacing nutrients. For nutrition's sake, the appropriate attitude to take is not that sugar is "bad" and must be avoided, but that nutritious foods must come first. If the nutritious foods end up crowding sugar out of the diet, that is fine—but not the other way around. As always, the goals to seek are balance, variety, and moderation.

• Dental Caries • Both sugars and starches begin breaking down to sugars in the mouth and so can contribute to tooth decay. Bacteria in the mouth ferment the sugars and in the process produce an acid that dissolves tooth enamel. People can eat sugar without this happening, though, for much depends on how long acid-yielding foods stay in the mouth. Sticky foods stay on the teeth longer and keep yielding acid longer than foods that are readily cleared from the mouth. For that reason, sugar consumed quickly in a soft drink, for example, is less likely to cause dental caries than sugar in a pastry. By the same token, the sugar in sticky foods such as dried fruits is more detrimental than its quantity alone would suggest.

Another concern is how often people eat sugar. Bacteria produce acid for 20 to 30 minutes after each exposure. If a person eats three pieces of candy at one time, the teeth will be exposed to approximately 30 minutes of acid destruction. But, if the person eats three pieces at half-hour intervals, the time of exposure increases to 90 minutes. Likewise, slowly sipping a sugary soft drink may be more harmful than drinking quickly and clearing the mouth of sugar. Nonsugary foods can help remove sugar from tooth surfaces; hence, it is better to eat sugar with meals than between meals.

The development of caries depends on several factors: the bacteria that reside in the plaque, the saliva that cleanses the mouth, the minerals that form the teeth,

Table 4-2

Sample Nutrients in

i Sugars and Other Foods

The indicated portion of any of these foods provides approximately '

100 kcalories.

Notice that for a similar

number of kcalories and grams of carbohydrate, milk, legumes, fruits, grains, and vegetables offer more of

the other nutrients than do the sugars.

Size of

100 kcal

Carbohydrate

Protein Calcium

Iron

Vitamin A

Vitamin C

Portion

(g)

(g)

(mg)

(mg)

(^g RE)

(mg)

Foods

Milk, 1% low-fat

1 c

12

8

300

0.1

144

2

Kidney beans

V2 c

20

7

30

1.6

0

2

Apricots

6

24

2

30

1.1

554

22

Bread, whole wheat

1'/2 slices

20

4

30

1.9

0

0

Broccoli, cooked

2 c

20

12

188

2.2

696

148

Sugars

Sugar, white

2 tbs

24

0

trace

trace

0

0

Molasses, blackstrap

212 tbs

28

0

343

12.6

0

0.1

Cola beverage

1 c

26

0

6

trace

0

0

Honey

1 '/2 tbs

26

trace

2

0.2

0

trace

and the foods that remain after swallowing.23 For most people, good oral hygiene will prevent dental caries.24 In short, sugars cause dental caries, but they require a cooperating victim to do so.

Accusations against Sugars

Sugars have been blamed for a variety of other problems. The following paragraphs evaluate some of these accusations.

  • Accusation: Sugar Causes Obesity • Foods high in added sugars are usually high in fat, too, so consumption of these foods increases total energy and fat intakes. Simultaneously, physical activity often declines. Thus sugar contributes to obesity as a companion to fat, not as the sole cause of obesity—and obesity can occur without a high-sugar consumption.25 The notion that eating sweet foods stimulates appetite and promotes overeating has not been supported by research.26
  • Accusation: Sugar Causes Heart Disease • Researchers agree that unusually high doses of refined sugar can alter blood lipids to favor heart disease.27 This effect is most dramatic in "carbohydrate-sensitive" individuals—people who respond to sucrose with abnormally high insulin secretion, which promotes the making of excess fat.28 For most people, though, moderate sugar intakes do not influence the risk of heart disease. To keep these findings in perspective, consider that heart disease correlates most closely with factors that have nothing to do with nutrition, such as smoking and genetics. Among dietary risk factors, several—such as total fats, saturated fats, cholesterol, and obesity—have much stronger associations with heart disease than do sugar intakes.
  • Accusation: Sugar Causes Misbehavior in Children and Criminal Behavior in Adults • Sugar has been blamed for the misbehaviors of hyperactive children, delinquent adolescents, and lawbreaking adults. Such speculations have been based on personal stories and have not been confirmed by scientific research.29 No scientific evidence supports a relationship between sugar and hyperactivity or other misbehaviors.30 Chapter 16 provides accurate information on diet and children's behavior.
  • U.S. Government www. healthfinder. gov/searchoptions/

topicsaz.htm

Search for Tooth decay

■ International Food Information Council ificinfo.health.org Search for Sugars

For perspective, each of these concentrated sugars provides 200 kcal:

  • 16 oz cola.
  • 2 oz jelly beans.
  • 54 c gelatin dessert.
Gelatin Rich Food
Foods rich in starch and fiber offer many health benefits.

■ International Food Information Council ificinfo.health.org Search for Fiber

The role of animal fat and cholesterol in heart disease is discussed in Chapter 5. The role of vegetable proteins in heart disease is discussed in Chapter 6.

Recommended Intakes of Sugars

The Dietary Guidelines urge people to use sugars only in moderation. Other recommendations specify that sugars should account for only 10 percent or less of the day's total energy intake. A person consuming 2000 kcalories a day, then, should receive no more then 200 kcalories (that is, 50 grams or less) from concentrated sugars.

Food labels list the total grams of sugar a food provides. This total reflects both added sugars and those occurring naturally in foods. A food is likely to be high in sugars if its ingredient list starts with any of the sugars named in the glossary on p. 107 or if it includes several of them.

IN SUMMARY

As currently consumed, sugars pose no major health threat except for an increased risk of dental caries. Excessive intakes may displace needed nutrients and fiber; when accompanied by fat, sugars may contribute to obesity. If on these grounds a person decides to limit daily sugar intake, it is important to recognize that not all sugars need to be restricted, just concentrated sweets, which are relatively empty of other nutrients and high in kcalories. Sugars that occur naturally in fruits, vegetables, and milk are acceptable.

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