SUCROSE ACETATE ISOBUTYRATE (SAIB) - HISTORICAL ASPECTS OF ITS USE INBEVERAGES AND A REVIEW OF TOXICITY STUDIES PRIOR TO 1988

Sucrose acetate isobutyrate (SAIB), a mixture of esters of sucrose wit h a composition approximating the name sucrose diacetate hexaisobutyra te, has been used for over 30 yr in many countries as a 'weighting' or 'density-adjusting' agent in non-alcoholic carbonated and non-carbona ted beverages. As part of the demonstration of safety of SAIB as a dir ect food additive in human diets, a program of toxicity testing was st arted in the late 1950s that culminated:in extensive studies of SAIB i n rodents, monkeys and humans over the last decade. This review summar izes the toxicity data, accrued up until 1988, that precede the safety studies published elsewhere in this issue. SAIB has been shown to hav e very low acute and chronic toxicities in rats, monkeys, and, except for effects on the liver, in dogs at feeding levels of up to 10% in th e diet. Slight effects seen in rats and monkeys at levels of 10% in th e diet are unlikely to be directly caused by exposure to SAIB. In dogs , however, SAIB causes decreases in bromosulfophthalein (BSP) and indo cyanine green (ICG) elimination from the serum immediately following a single dose, indicative of interference with biliary excretion. On re peated feeding in dogs, SAIB caused increases in serum alkaline phosph atase levels, but enzymes indicative of toxic effects on the liver wer e unaffected: On prolonged feeding to dogs, SAIB caused changes in liv er morphology revealed by electron microscopy. All of these effects we re reversed when SAIB was withdrawn from the diet. The no-effect level for these effects in dogs was near 5 mg/kg body weight, but these eff ects were not seen in rats fed up to 4 g/kg body weight/day, monkeys f ed up to 10 g/kg body weight/day, or humans fed up to 20 mg/kg body we ight/day. The toxicity and pharmacological studies in dogs, rats and m onkeys suggest that the effect of SAIB on biliary excretion and liver morphology in dogs is essentially pharmacological rather than toxicolo gical in nature and that the difference between the effects in dogs at levels as low as 5 mg/kg body weight/day, and the lack of effects in rats or monkeys at levels up to 10 g/kg/day is not merely a quantitati ve difference between species, but an absolute qualitative difference. (C) 1998 Elsevier Science Ltd. All rights reserved.