Excessive Fruit Juice Intake by Infants and Young Children Lynda Clark Lowry MS PHEc Rich in Vitamin C, free of fat, a readily digestible source of energy, and a "natural" beverage, fruit juice has long enjoyed a wholesome reputation. When the popular press reported on the findings of Smith and Lifshitz to contest its nutritive value, parents were astonished to learn that excessive consumption of fruit juice could lead to malnutrition! 1More recent work 2and the contents of a supplement to the Journal of the American College of Nutrition 3support the concern that has been expressed. But, just how much juice is too much? Fruit juice has become a staple in the diet of children and adults over the past 50 years since technology allowed excess orange production to be made into juice concentrate and reconstituted into juice. It is a source of energy, an excellent source of vitamin C, well tolerated, convenient and popular even during illness. Ninety percent of all infants in the United States consume juice by 1 year of age 4. Fifty percent of all infants enjoy apple juice. It is followed in popularity by white grape and then orange juice. Juice accounts for 50% of all fruit servings consumed by children. The typical serving of juice offered to a one-year old is 5-7 ounces per day. However, Smith and Lifshitz found that 16% of their sample of 50 toddlers aged 14-27 months, referred to a failure to thrive clinic, drank more than 12 fluid ounces per day. 1These children showed growth deficiencies until their diets were corrected. Other researchers have found that the intake of pear nectar and apple juice was associated with gastrointestinal (GI) symptoms and/ or diarrhea from carbohydrate malabsorption. 5Others have observed a relationship between excess juice consumption and obesity in children. 2 Table 1
The digestibility, absorption and tolerance of fruit juices are determined by the type and concentration of carbohydrate, the amount of sorbitol present as well as fibre content. 6,7The soluble fibres modulate the gastric emptying and manifest different water-holding capacities and viscosity. This can prolong gastric emptying time. Several principles of carbohydrate, particularly sugar, metabolism can be briefly stated. Fruit juices contain varying proportions of fructose, sucrose and glucose as well as sorbitol. Sorbitol is a polyalcohol sugar which occurs naturally in some fruit juices (pear, prune, apple) as well as in cherries, apricots and plums. It is malabsorbed by healthy individuals and this is the basis for its use as a sugar-free product. 7The capacity to absorb fructose and sorbitol is more limited in children than in adults. Fructose may be incompletely absorbed depending on the presence of glucose and sorbitol. Dietary fructose in equivalent quantities to glucose is readily absorbed. However, sorbitol inhibits fructose absorption while glucose stimulates fructose uptake in a dose-dependent fashion. Fructose in excess of glucose is found in apple and pear juices (Table 1). When appetite is reduced following acute gastroenteritis, infants may lose interest in milk or formula and drink large quantities of juice. If apple or pear juices are consumed in large amounts, malabsorption of fructose may contribute to GI symptoms and cause more discomfort, further complicating gastric distress. Lack of digestion of carbohydrates presents different problems. Young infants with an incompletely developed fecal flora and an immature colon, may develop diarrhea as a consequence of being unable to handle the non-absorbed dietary carbohydrate. Somewhat older infants may experience discomfort and pain when gas is produced in the colon during fermentation of unabsorbed carbohydrates. 8 Several approaches can effectively address problems associated with juice intake. Elimination of fruit juices from the diet of children with persistent non-specific diarrhea has been associated with the cessation of symptoms. Dilution of juices or substitution of grape for apple juice has also eliminated diarrhea in some children. White grape juice contains equivalent amounts of fructose and glucose without sorbitol and is better absorbed. A major concern reported by Smith and Lifshitz was that the toddlers (aged 14-27 months) who presented with failure-to-thrive, had used fruit juice to displace more nutritious foods from the diet, resulting in a slowing of growth. 1These children had lower-than-normal intakes of fat and protein and consequently their diets were also low in calcium and vitamin D, iron and zinc. Resolution of the growth failure occurred with a reduction in the amount of juice consumed, an increase in total calories and the adoption or a more balanced diet. In contrast, Dennison, Rockwell and Baker found in their study of 100 older children, that obesity was more common among the 19 two - and five - year old children who drank more than 12 fluid ounces of fruit juice every day. 2These children had a lower intake of total fat and saturated fat but a greater percentage of calories from sugar. After adjustment for maternal height, child age, child sex and child age-sex interaction, children drinking more than 12 fluid ounces per day were shorter and more overweight than those who drank less than 12 ounces per day. Since there is no pathophysiological mechanism by which a child with sufficient calories to produce obesity can at the same time be deficient in other nutrients to produce shortness of stature, this characteristic of height is likely an artifact of a relatively small sample size. It is well recognized that infants prefer sweetened liquids to those without sugar and that consumption is directly related to the concentration of sweetness. It is therefore feasible that infants may willingly take a sweet juice whenever offered and may not be as interested in other foods. During the first half of an infant's life when breast milk or infant formula make up the diet, There is little or no need for water or juice. 10When protein foods with higher solute load are introduced, water is preferred to juice because it fulfills the fluid needs without added calories. Juice is best added to the diet when the infant learns to drink from a cup. Juice in bottles when used as a pacifier and prolonged bottle feeding, predisposes the infant to dental caries and this practice should be discouraged. 11In the evaluation of infants, concern needs to be exercised with the possibility of juice displacing other foods resulting in failure to thrive. For all care givers, it is prudent to limit the daily intake of juices to less than 12 fluid ounces. 12 References
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