Corn sugar, commonly referred to as dextrose, is crystalline ?-D-glucose. Glucose is widely distributed in nature both in the free state and in various combined forms, including starch and sucrose. Glucose-yielding carbohydrates constitute one of the main sources of energy in the typical North American diet. Fructose, produced along with glucose in the hydrolysis of sucrose to invert sugar and by isomerization of dextrose, also is a significant calorie source. The absorption and metabolism of these sugars are well established. Biological studies have shown that these substances are devoid of toxic effects at dosage levels well in excess of those that exist in the American diet and, accordingly, at levels that are orders of magnitude higher than those which might occur from the migration of these substances from paper and paperboard products.
Glucose syrup, also called corn syrup when made by the hydrolysis of corn starch, contains in addition to glucose, maltose, and higher saccharides in proportions that depend on the degree of hydrolysis of the starch. The higher conversion syrups may also contain small amounts of disaccharides formed by the recombination of glucose through glucosidic linkages not present in starch. Animal feeding studies have shown that glucose syrups are readily digested and metabolized and have given no evidence of toxic effects.
Fructose-dextrose mixtures have been observed to have hyperlipemic effects when fed at high levels in fat-free diets to adult males and postmenopausal women. There is no evidence, however, that the levels of invert sugar and high-fructose corn syrup in the average diet cause significant elevations in blood lipids and it is unlikely that the consumption of fructose or glucose, ingested as monosaccharides, has a role in coronary heart disease. Although glucose and fructose as well as sucrose have been demonstrated to be cariogenic in animal experiments, epidemiological studies of dietary habits and controlled diets in institutional feeding indicate that the cariogenicity of sucrose and other foods is affected by several factors and not necessarily by the total amount consumed. These factors include the frequency eating, duration of exposure, and the form and physical properties of the food in which the sugar is ingested. Between-meal eating has been demonstrated to be significantly correlated with frequency and severity of caries in both children and adults. Thus, protection is facilitated by limitation of the frequency of consumption of sugar and sugared foods.k
Consumption of dextrose and corn syrup has increased markedly in recent years and represented about 21 percent of the sweetener marker in 1974 as compared to about 15 percent in 1970. A major part of the increase resulted from the introduction of high-fructose corn syrup produced the enzymatic isomerization of dextrose in starch hydrolyzates. Level of fructose as the monosaccharide in the diet has increased accordingly but 1974 per capita daily consumption of this monosaccharide from all sources was only 6g and no higher than in 1925-29, when apples provided a larger contribution than at present. High-fructose corn syrups are predicted to increase in production and to replace sucrose and invert sugar in up to 30 percent of their applications by 1980-85, based largely on relative costs. There is no evidence that such replacement, per se, would have an adverse effect on public health. However, the Select Committee has expressed concern in its report on sucrose (73) that is this sugar contributes to dental caries in the public at current consumption levels as used in the manner now practiced. It is questionable that replacement of sucrose by syrups and sugars derived from starch would greatly change the cariogenicity of foods containing these sugars. Informing the consumer of the sugar content of foods by appropriate labeling could lead to judicious use of sweetened foods. Choices could be made easier with a greater selection of less sugared foods in the market place. The Select Committee has weighed all of the foregoing and concludes that: Evidence exists that simple sugars, including glucose and fructose [and, therefore, corn sugar(dextrose), corn syrup including high-fructose corn syrup, and invert sugars] are cariogenic. However, in the quantities that these simple sugars are now consumed in processed foods, their contribution to formation of dental caries should be relatively small. If increased usage should occur, as seems likely, the contribution of these sugars to the occurrence of dental caries might become more important. Other than the contribution made to dental caries, there is no evidence in the available information on corn sugar(dextrose), corn syrup, and invert sugar that demonstrated a hazard to the public when they are used at levels that are now current and in the manner now practiced. however, it is not possible to determine without additional data, whether an increase in consumption-that would result if there were a significant increase in the total of corn sugar, corn syrup, invert sugar and sucrose added to foods-would constitute a dietary hazard.