Healthy Dietary Pattern Reduces Risk of Gallstones: Results of a Case-Control Study in Iran

BACKGROUND: Nutrition-related factors have been of great interest as one of risk factors of biliary stones. This study evaluated the association of dietary patterns with biliary stone among Iranians. METHODS: This is a hospital-based case-control study, which was conducted in a general hospital in Tehran, Iran. A total of 110 patients with gallstone or common bile duct (CBD) stone confirmed by Ultrasonography within the last 6 months before collecting data were recruited. Controls were age-matched patients admitted to the other wards of the same hospital for a broad spectrum of disorders including traumas and orthopedic conditions, or elective surgeries, or throat/ear/nose disease and had no gallbladder disorders, participated in this study. We used a valid and reliable food frequency questionnaire to assess dietary intakes of participants. Dietary patterns were determined by factor analysis. RESULTS: By design, age was similar in both groups (57.66 ± 16.39 years vs. 56.00 ± 10.64 years in cases and controls, respectively). Two dietary patterns were extracted; “Unhealthy” (high consumption of artificial juice, processed meats, refined grains, sweets and desserts, pickles, snacks, and red meats), and “Healthy” (high consumption of vegetable oils, vegetables, fruits, fish, legumes, and nuts, as well as low consumption of hydrogenated fats and salt). Participants in the highest tertile of “Healthy” dietary pattern were significantly less likely to have the gallstones disease (OR: 0.33, 95% CI = 0.120.89) compared to the reference group (low tertile of “Healthy” dietary pattern) (P = 0.02). CONCLUSIONS: High consumption of vegetable oils, vegetables, fruits, fish, legumes, and nuts, as well as low consumption of hydrogenated fats and salt in context of healthy dietary pattern are inversely associated with risk of gallstones.