Antidiabetic effect of D-tagatose in shr/n-cp rats.

The FASEB Journal. 1996: 10: A461.

Abstract

The effects of D-tagatose on diabetic symptoms were investigated in the SHR/N-cp rat. Diets contained the following ingredients (%): fructose (24), glucose (10), starch (10), fat (16), lactalbumin (10), casein (10), cellulose (5.9), AIN salt mix (3.1) and vitamins (1.0). An additional 10 percent of the diet was either D-tagatose (TAG) or fructose (FRU). In a long-term experiment (6 months, 9 diabetic, obese rats), the TAG diet resulted in normal water intake, while rats given the FRU diet had marked polydipsia during the first three months. Average food efficiency at 2-month intervals was as follows (TAG vs FRU): 0-2 months (14.7 vs 10.3): 2-4 months (7.6 vs 7.5); 4-6 months (5.0 vs 7.9). The increase in the food efficiency in the TAG group during the first two months was probably due to the elimination of polydipsia, whereas during the last two months (when polydipsia was absent in both groups), food efficiency was lower in the TAG group. In a second experiment (5 lean, 5 diabetic, obese) rats were given the FRU diet for two weeks, the TAG diet for two weeks, then the rotation was repeated. TAG reduced food efficiency in the lean, but had the opposite effect in the obese: polydipsia and urine glucose were reduced in the obese. These effects were even larger during the second rotation: food efficiency was reduced even in the obese, and urine glucose output was near normal. No pathological lesions were found in any rats. In obese rats given the TAG diet, kidney caicium was increased; probably reflecting improved calcium retention due to the elimination of polydipsia. The results indicate that D-tagatose is a strongly antidiabetic carbohydrate, that some or all of its energy is lost during metabolism and that it induces a "metabolic memory" of increased effects to its use when it is fed a second time.