Antihyperglycemic Effect of D-allulose in Dogs Given Oral Glucose

Oral D-allulose blunted plasma glucose and insulin elevations after oral glucose administration in dogs, according to a report published in the Journal of Veterinary Medical Science. However, D-allulose did not affect dogs’ plasma glucose or insulin levels after a meal.

D-allulose, also called D-psicose, is a monosaccharide that has attracted interest as a possible sugar substitute and has also been shown to have an antihyperglycemic effect in humans. Investigators from Japan tested the effects of D-allulose on plasma glucose and insulin levels in 7 beagles given oral sugar (glucose or maltose), intravenous glucose, and food.

In the oral sugar test, dogs received 2.0 mg/kg of 50% glucose or 50% maltose supplemented with either 0.2 g/kg of D-allulose or an equivalent volume of water by mouth. Blood samples were collected before and 30, 60, 90, and 120 minutes after sugar intake. Plasma glucose and insulin levels increased after sugar consumption in all dogs. The increases in both glucose and insulin were significantly lower in the D-allulose group than in the control group.

In the intravenous glucose test, dogs were given 0.2 g/kg of oral D-allulose or water one hour before an intravenous injection of 50% glucose (0.5 g/kg). The researchers collected blood samples before and 5, 10, 15, 30, and 60 minutes after glucose injection. Plasma glucose and insulin levels rose in all dogs after glucose administration. The plasma glucose level was significantly lower in the D-allulose group than in the control group at 5, 10, and 15 minutes after glucose injection. Plasma insulin levels did not significantly differ between the two groups.

In the feeding test, dogs were given dry dog food (amount based on body weight) along with 0.2 g/kg of oral D-allulose or an equivalent volume of water. Blood samples were collected before and 1, 2, 3, 4, 6, and 8 hours after feeding. After the meal, the dogs’ plasma glucose levels did not change but the plasma insulin levels rose. The results in the two groups were not significantly different.

The authors conclude that the effect of D-allulose on plasma glucose after oral or intravenous glucose administration was not caused by an increase in plasma insulin. Previous studies have shown that D-allulose inhibits digestive enzyme action and intestinal glucose absorption, which could explain the antihyperglycemic effect after oral sugar consumption. The mechanism by which D-allulose affects plasma glucose after intravenous glucose administration is unclear but could be related to hepatic glucose metabolism, say the authors.

In humans, D-allulose has been shown to decrease plasma insulin levels after a meal. According to the authors, differences in nutrient composition of the meals (specifically carbohydrate content) could explain the conflicting results of this study.

D-allulose administration might be helpful for dogs with impaired glucose tolerance, write the authors. However, because it did not affect plasma glucose or insulin levels after a meal, they conclude that its therapeutic utility in diabetic dogs needs further investigation.

Dr. Laurie Anne Walden received her doctorate in veterinary medicine from North Carolina State University. After an internship in small animal medicine and surgery at Auburn University, she returned to North Carolina, where she has been in small animal primary care practice for over 20 years. Dr. Walden is also a board-certified editor in the life sciences and owner of Walden Medical Writing, LLC.