Objective: This study aimed to examine the metabolic effects of high fructose corn syrup (HFCS) in dental tissues and parotid glands of rats and antioxidant defense of alpha-lipoic acid (ALA) in HFCS-induced effects. Materials and Methods: Female Wistar rats (n=24) divided into three groups (group 1: negative control, group 2: positive control, and group 3: ALA) with each group consisting of 8 animals. Rats in groups 2 and 3 were subjected to HFCS for 10 weeks. ALA was given to the animals in group 3 for the last 6 weeks of the experiment. The rats were euthanized by cervical dislocation. The tissues were prepared for histopathological, and immunohistochemical [caspase-3, caspase-8 and bone moprhogenetic protein-2 (BMP-2)] evaluations. Data were analyzed by Kruskal-Wallis (non-parametric data) and one-way ANOVA tests (parametric data) (p<0.05). Results: Hyperemia and neutrophil leukocyte infiltrations in dental tissues and sialadenitis characterized by severe inflammatory reactions in the parotid gland were observed in group 2. After the ALA treatment, degenerative changes were decreased in both tissues, and the gland recovered an essentially normal appearance. Group 3 exhibited significantly lower inflammatory scores than the group 2 in terms of dental pulp (p=0.044). Both BMP-2 values and caspase-3 cell counts of the gingival tissue were significantly lower in group 3 compared to group 2 (p<0.01). Conclusion: The vascular and pulpal tissue damage caused by corn syrup was determined in this study. It was concluded that ALA could be a potential antioxidant against the harmful consequences of corn syrup consumption.