The Association Between Plant-Based Diet and Gallstone Disease: A Case-Control Study.

Background: Recent studies have emphasized the role of plant-based diets in reducing the risk of gallstone disease (GD) by reducing oxidative stress and inflammation. This study aimed to investigate the association between plant-based diet indices and GD risk. Methods: 189 patients with newly diagnosed GD and 342 healthy controls participated in this case-control study. To assess overall adherence to a plant-based diet, three indices were calculated based on dietary data from the food frequency questionnaire: the plant-based dietary index (PDI), the healthful PDI (hPDI), and the unhealthful PDI (uhPDI). The association between plant-based diet indices and the risk of GD was assessed using logistic regression models. Results: A significant and inverse association was observed between PDI and the risk of GD, with an odds reduction of 48% in the crude model, 56% when adjusted for age and sex, and 59% when adjusted for additional confounders. Similar results were obtained for hPDI. Increasing the hPDI was associated with a 53% (in the crude model) to 67% (in the full adjusted model) reduction in the odds of GD. While increasing uhPDI was associated with an increased odds of GD. In the crude model, the highest uhPDI score increased the odds of the disease by 70%, and in the final model, the increase in odds reached 2.2-fold. Conclusion: Our study revealed that a healthy plant-based diet is associated with a reduced risk of GD, whereas an unhealthy plant-based diet may contribute to a greater susceptibility to disease, emphasizing the importance of diet quality in plant-based nutritional approaches. Further studies are needed to confirm these findings.