Cinnamon Powder Intake Enhances the Effect of Caloric Restriction on White Adipose Tissue in Male Rats

Caloric Restriction (CR) and cinnamon promote several benefits, including the modulation of lipid metabolism and body fat mass. We hypothesize that cinnamon may act as a mimetic of restriction or enhance the effects of caloric restriction on adipose tissue. Adult male Wistar rats were divided into Control (CT, n = 8) and Cinnamon (CIN, n = 7), with free access to standard chow; Calorie Restriction (CR, n = 8) and Calorie Restriction with Cinnamon (CIN-CR, n = 7), subjected to a 30% reduction in food intake compared to the average consumption of CT rats. Both CIN groups received 50 mg cinnamon powder (Cinnamomun verum) per kg body mass, by gavage, over 6 weeks. Cinnamon treatment did not alter food intake under either ad libitum or caloric restriction conditions. The CR and CIN-CR groups exhibit lower body mass. Basal glycemia, lipid profile, and triglyceride-glycemic index were similar between groups. The combination of both interventions induced lower visceral white adipose tissue (WAT) mass, and smaller adipocyte diameter in the visceral and subcutaneous WAT compartments, accompanied by reduced expression of genes related to lipid metabolism (Acaca, Fasn, Cd36, Srebf1c), suggesting decreased lipid synthesis. Histological analyses identified a browning phenotype in the CR, CIN, and CIN-CR groups, positive for UCP1 immunostaining. The CR and CIN-CR groups showed lower Atg7 expression, and CIN-CR animals expressed increased levels of Lamp2, suggesting modulation of autophagy. Brown adipose tissue mass and lipid content were not influenced by any intervention. These findings suggest that cinnamon may enhance the effects of caloric restriction in promoting adipocyte metabolic health.