Association between dietary phytochemical index and pancreatic steatosis in patients with common bile duct stones

The dietary phytochemical index (DPI) may protect against pancreatic steatosis (PS), but evidence is limited. This study examined the association between DPI and PS risk. This case-control study included 278 patients with common bile duct stones at Taleghani Hospital, Tehran, between July 2022 and May 2023. The case group comprised 89 patients with PS, and the control group included 189 patients without PS. Dietary intake was assessed using a validated 168-item food frequency questionnaire, and the DPI was calculated as the percentage of total daily energy from phytochemical-rich foods, including fruits, vegetables, legumes, whole grains, nuts, soy products, seeds, and olive oil. Participants were categorized into tertiles of DPI (< 15.7%, 15.7 to < 30.6%, ≥ 30.6%). Logistic regression was used to assess PS odds across DPI tertiles in three models. Participants in the highest DPI tertile had higher fruit and vegetable intake and lower total energy intake than those in the lowest tertile. Higher DPI was associated with significantly lower odds of PS. In the crude model, participants in the highest tertile had 65% lower odds of PS compared with the lowest tertile (OR 0.35; 95% CI 0.18–0.69; p = 0.008). After adjusting for age and sex, the association remained significant (OR 0.29; 95% CI 0.14–0.59; p = 0.002). In the fully adjusted model, the highest DPI tertile exhibited 77% lower odds of PS (OR 0.23; 95% CI 0.11–0.51; p < 0.001), with a significant inverse trend across tertiles ( p -trend < 0.001). Higher dietary phytochemical intake was associated with lower odds of PS. Prospective studies are warranted to confirm these findings and clarify the temporal relationship.