Dietary phytochemical index and the risk of gallstone disease: a case-control study

BACKGROUNDSː: Dietary phytochemical index (DPI) is an inexpensive method for estimating the amounts of phytochemicals in foods. No study has investigated the association between DPI and gallstones disease (GSD). Therefore, we conducted a case-control study in adults to assess the relationship between DPI and the risk of gallstones.

The study was conducted at the general surgical consultation departments of two major multispecialty hospitals in Baghdad: Al-Yarmook and Al Karama Teaching Hospitals. It involved 250 patients with gallstones and 250 controls. DPI was calculated based on data collected from a 168-item validated food frequency questionnaire. Sociodemographic data, physical activity, and anthropometric measures were determined.

In the initial analysis, the highest tertile of total PI compared to the lowest tertile was found to be associated with a lower risk of galleston (OR and 95% CI = 0.61 (0.41-0.93), p for trend = 0.027). This significant association remained even after adjusting for age and sex, and the odds ratio slightly strengthened. In the final adjusted model, which accounted for additional confounders such as physical activity, BMI, smoking, socioeconomic status (SES), and dietary intake of energy, participants in the highest tertile of total PI still had a lower risk of gallston compared to those in the lowest tertile (OR and 95% CI = 0.51 (0.28-0.90), p for trend = 0.031.

We found evidence of a negative relationship between the dietary phytochemical index and the risk of gallstones, even after accounting for potential confounding variables. As a result, it may be advisable to include more phytochemical-rich foods in dietary approaches aimed at preventing gallstones. However, additional studies are needed to confirm the link between the dietary phytochemical index and gallstone.