Aspartame Metabolism in Normal Adults, Phenylketonuric Heterozygotes, and Diabetic Subjects

Abstract

This study reviews clinical studies testing the effects of various doses of aspartame on blood levels of phenylalanine, aspartate, and methanol in normal subjects and known phenylketonuric heterozygotes. The effect of aspartame on the phenylalanine-to-large neutral amino acid ratio under various feeding situations is shown. The clinical studies of aspartame in diabetic subjects are limited to observations of its effects on blood levels of glucose, lipids, insulin, and glucagon. These studies clearly demonstrate the safety of this high-intensity sweetener for use by humans. Diabetes Care 12:67-74, 1989 I n the United States the prevalence of diabetes, both insulin dependent (IDDM) and non-insulin dependent (NIDDM), involves 2.7% of women and 2.0% of men (1). In 1976, it was projected that the incidence of diabetes was increasing at a rate of 6%/yr (2). The association of NIDDM with the degree and duration of obesity suggests one reason why high-intensity sweeteners, nutritive and nonnutritive, may be a component of foods eaten by diabetic individuals. The natural interest of humans in the sweet taste modality provides another rationale for incorporation of high-intensity sweeteners into the diet of diabetic individuals. Currently, the most widely consumed high-intensity sweetener is aspartame, a dipeptide methyl ester (L-aspartyl-L-phenylalanine methyl ester).On the basis of total pounds of aspartame sold to food and beverage processors, it has been estimated that as- Daily intake can be calculated and amounts to 104 mg/day or 1.5 mg/kg body wt for a 70-kg individual. Aspartame is rarely consumed alone but is usually ingested in conjunction with varying proportions of carbohydrate, protein, and fat. Unless a person drinks an aspartame-sweetened beverage, carbonated or still, as a refreshment, the intake usually involves other foods. Aspartame-containing carbonated soft drinks provide 150-200 mg of aspartame per serving (12 oz or 360 ml). Noncarbonated beverages usually contain 140 mg per serving (8 oz or 240 ml). For the average 70-kg adult or 20-kg 4-yr-old, aspartame intake under these amounts would approximate 3-10 mg/kg body wt. The Market Research Corporation of America (MRCA) has projected the 99th percentile of daily intake of aspartame at 34 mg/kg body wt (3). Accordingly, the clinical studies highlighted in this review bracket aspartame intakes that range from 4 to 200 mg/kg body wt. These studies largely represent single-bolus doses of aspartame given to normal adult subjects, known adult phenylketonuric (PKU) heterozygotes, or normal 1-yr-olds. Aspartame was administered in orange juice, in a noncarbonated beverage, as part of a hamburger and milk shake meal, or in a beverage ingested at repeated intervals. Aspartame doses >50 mg/kg body wt were considered to represent abuse doses; i.e., 100-200 mg/kg body wt. Based on the relative sweetness of aspartame to sucrose, abuse intakes of this magnitude represent an acute intake of sweetness equivalent to 3-6 Ib of sucrose. Participants in the latter clinica...

Glycemic impact of non-nutritive sweeteners: a systematic review and meta-analysis of randomized controlled trials

“…In addition to having a range of sweetness intensities, the structural differences lead to different amounts of NNSs absorbed and post-ingestive behaviors [55][56][57][58][59][60][61]. Despite these differences, our results suggest no differential glycemic impact by type of NNS.…”

Caracterização do consumo de adoçantes alternativos e produtos dietéticos por indivíduos diabéticos

“…Eles podem facilitar a manutenção da dieta, já que desta forma o paciente pode tanto suprir seu desejo pelo sabor doce, como também assistir o controle da ingestão calórica (12)(13)(14).…”

Nutrition and Behavior

“…Most of these people are unaware that they carry a gene for PKU. Fasting plasma phenylalanine levels are not markedly elevated in these individuals, and phenylalanine hydroxylase activity appears sufficient for normal functioning (Filer and Stegink 1989). The ability to metabolize phenylalanine into tyrosine, however, is diminished by half in individuals carrying the recessive gene.…”