The 90-day oral toxicity of d-psicose in male Wistar rats.

d-Psicose is a rare sugar present in small quantities in natural products. In a previous study, we showed that d-psicose suppresses increase in plasma glucose and reduces body fat accumulation in rats. Based on acute toxicity testing in rats, d-psicose is classified as an ordinary substance (LD(50) = 16 g/kg). Elucidating the effects of sub-chronic feeding of d-psicose in rats is essential before it can be utilized as a physiologically functional food. In this study, male Wistar rats (3 weeks old) were fed diets containing 3% d-psicose or sucrose for 90 days. The body weight gain and intra-abdominal adipose tissue weight did not differ between the sucrose and the d-psicose groups. The weights of the liver and kidneys were significantly higher in the d-psicose group than in the sucrose group. However, no gross pathological findings were evident at dietary doses of 3% d-psicose or were correlated with hypertrophy of the liver and kidney. In a clinical chemistry analysis, the erythrocyte and leukocyte courts were significantly higher in the d-psicose group, but that was not considered to be toxicologically significant. Therefore, the present study found no adverse effects of d-psicose in rats fed a diet containing 3% d-psicosefor 90 days.