Effects on Body Mass of Laboratory Rats after Ingestion of Drinking Water with Sucrose, Fructose, Aspartame, and Sucralose Additives

The excessive consumption of natural sweeteners is considered to be a major cause of increase in body mass. The authors wished to establish whether hypocaloric artificial sweeteners also promoted mass gain in laboratory rats (Harlan Wistar male rats). Ad libitum sweeteners were added to the drinking water of five groups of nine male rats each weighing circa 40g: Group 1, 15% fructose; group 2, 10% sucrose; group 3, 0.3% aspartame; group 4, 0.19% sucralose; and group 5 (control), ordinary drinking water. The daily volume of water consumption, the amount of ingested food, and gain of body mass were assessed during 73 days. Histological sections of the liver tissue of these rats were analyzed using Sudan and Hematoxylin-Eosin red staining. Results indicated that the fructose solution promoted the highest final gain in body mass, statistically different from the control and sucrose groups (p<0.05). The caloric consumption was similar to that of the sucrose group, but different from that of the control and one of the groups consuming hypocaloric sweeteners, aspartame (p<0.05). Rats that ingested sucrose solutions had the lowest final body mass in spite of the fact that their total caloric intake was one of the highest, and as mentioned, similar to fructose. Rats that drank water with hypo-caloric artificial sweeteners, aspartame and sucralose ingested the same amount of food, and the caloric intake was similar to the control group (p<0.05). They were fatter than the control and sucrose groups, although their caloric consumption was lower than that of the fructose-drinking specimens, apparently confirming recent findings about glucose absorption with ingestion of artificial sweeteners. The behavior of the sucralose group, with a body mass higher than those of the control and sucrose groups, should be further studied, since this group showed a tendency to drink more water over time when compared to the control and aspartame groups. Liver-to-body mass ratios were not statistically different (p<0.05) among the five groups, but both groups consuming hypocaloric sweeteners had slightly lower ratios than the sucrose, fructose, and control groups. As has been mentioned in previous research, ingestion of fructose solutions led to an increase of lipids in the liver tissue, in comparison with the other groups studied. Groups consuming hypocaloric sweeteners also showed a slight increase in lipid accumulation in liver tissue but not as much as the fructose-consuming group. The results of these experiments indicate the advisability of a long term experiment focusing on the ingestion of these sweeteners and their role in the increase in body mass.