Title: Alternative Sweeteners

344 Olinger and Pepper
Besides laborious and expensive energy balance trials, only indirect calorimetry
allows one to determine the energetic use of substrates in humans. By
use of this noninvasive technique, the energetic use of xylitol was examined in
10 healthy volunteers (96). The results of this study revealed that, during a 2.5hour
period, the cumulated increase in carbohydrate oxidation amounted to only
one fourth of that caused by glucose. The total increase in metabolic rate was
52% lower after the xylitol load than after the glucose treatment. This result
suggests that xylitol has a caloric value of only about 50% that of glucose. Considering,
however, that the absorption (and hence metabolic use) of the bacterial
fermentation products may not have been complete within the 2.5-hour experimental
period, it is likely that the true caloric value for xylitol is somewhat higher
than the proposed 2 kcal/g. The net energy value of 2.4 kcal/g has been assigned
to xylitol by FASEB. The net energy is defined as that portion of gross energy
intake that is deposited or mobilized in the body to do physical, mental, and
metabolic work (92).
Food regulatory authorities are increasingly taking note of the reduced caloric
value of polyols, which is by now well supported by a still growing volume
of scientific literature. In the EU, a caloric value of 2.4 kcal/g has been allocated
for all polyols including xylitol (Council Directive No. 90/496/EEC of 24 September
1990 on nutrition labelling for foodstuffs (Off. J. European Communities
1990, 33 (L276), 42–46). On the basis of the 1994 FASEB review, the Food and
Drug Administration acknowledged the xylitol caloric value of 2.4 kcal/g (letter
to American Xyrofin Inc from FDA concerning use of a self-determinated energyvalue
for xylitol; 1994).
VI. DENTAL BENEFITS
A. Caries Formation
According to current knowledge, dental caries is caused by bacteria that accumulate
in large masses, known as dental plaque, on the teeth in the absence of
adequate oral hygiene. Fermentation of common dietary carbohydrates by plaque
bacteria leads to the formation of acid end-products. Acid accumulation and a
decrease in plaque pH will follow. A decrease in plaque pH caused by bacterial
fermentation of carbohydrates may lead to undersaturation of the plaque with
respect to calcium and phosphate ions, to demineralization of the tooth enamel,
and eventually to formation of a cavity.
Approaches aimed at the prevention or elimination of dental caries include
reduction of acid dissolution of tooth mineral and stimulation of enamel remineralization
by fluoride, removal of dental plaque by brushing the teeth, and reduc-