Dextrans are polysaccharides composed of ?-D-glucopyranose units and are commercially prepared by the action of bacterial enzymes on sucrose. They occur naturally in small amounts in such foods as refined crystalline sugar, maple syrup, sauerkraut juice and honey and also as a component of dental plaque.
No use of dextran in food was reported in the 1970 survey of food processors conducted by a NRC subcommittee and the Select Committee concludes that any undisclosed use was probably small. More recently, however, one company has marketed a beverage product containing dextran. Current distribution and use of this product also appear to be small.
Oral ingestion studies in animals and man have shown that dextran is broken down by intestinal enzymes and is absorbed from the gastrointestinal enzymes and is absorbed from the gastrointestinal tract. Intravenously administered dextran also is metabolized in animals and man. Weight gain of rats fed diets containing 15 percent dextran in short-term test was comparable to that on a glucose supplemented diet indicating good utilization of dextran as an energy source. No adverse physiological effects were noted in these test nor were any reported in acute toxicity tests.
The absence of evidence of harm in the limited biological test that have been conducted and the extensive use of dextran as a blood volume expander without untoward effects, except for reaction of an allergic type in a low percentage of patients, support the opinion of the Select Committee that the use of dextrain in food at present levels poses no problem. However, there is no long history of use of dextran as an ingredient of food products. Should the level of use be increased, particularly as a beverage product in which dextran is a major component, the existing scientific data are insuficient for judgment as to possible health hazards.
In the light of the foregoing, the Select Committee concludes that: There is no evidence in the available information on dextran that demonstrates a hazard to the public when it is used at levels that are now current and in the manner now practiced. However, it is not possible to determine without additional data, whether a significant increase in consumption would constitute a dietary hazard.