The association between dietary acid load and risk of gallstone: a case-control study.

Background and aim: While dietary factors are known to influence gallstone disease (GD), the specific role of dietary acid load (DAL) remains unclear. This study aimed to explore the relationship between DAL and GD risk using a case-control design.

Methods: The study included 189 adults with newly diagnosed GD and 342 controls. Anthropometric data were collected, and DAL was calculated using the potential renal acid load (PRAL) and net endogenous acid production (NEAP) indices. Multivariable logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI), adjusting for confounders.

Results: Participants in the higher tertiles of both PRAL and NEAP scores showed notably elevated grain consumption and reduced intake of vegetables and fruits (P < 0.001). Conversely, an inverse relationship was observed between NEAP scores and intake of legumes, nuts, and seeds (P = 0.044). After adjustment for confounders, the risk of GD was 25% higher in the second tertile (OR: 1.25; 95% CI: 0.9, 2.3) and 51% higher in the third tertile (OR: 1.51; 95% CI: 0.54, 1.36) of PRAL compared to the first tertile (P trend = 0.023). A similar trend was seen for NEAP, with a 19% increased risk in the second tertile (OR: 1.19; 95% CI: 0.78, 1.84) and 48% in the third tertile (OR: 1.48; 95% CI: 0.9, 2.3) relative to the first tertile.

Conclusions: Higher dietary acid load is associated with an increased risk of GD. Further studies are needed to confirm these findings and elucidate underlying mechanisms.