The prevalence of gallstones is increasing in association with the obesity epidemic, but rapid weight loss also increases the risk of stone formation.
Dr Frank Lammert and colleagues from Germany conducted a systematic review of the efficacy of strategies to prevent gallbladder stones in adults as they lose weight.
The team identified randomized controlled trials of nonsurgical strategies to prevent gallstones by electronic and manual searches.
The team's final analysis included 13 trials, comprising 1836 participants undergoing weight loss through dieting or bariatric surgery.
The trials compared ursodeoxycholic acid (UDCA) or high-fat weight loss diets with control interventions.
|Ursodeoxycholic acide reduced the risk of cholecystectomy for symptomatic stones |
|Clinical Gastroenterology & Hepatology|
The research team performed random-effects meta-analyses and evaluated heterogeneity and bias with subgroup, sensitivity, regression, and sequential analysis.
UDCA reduced the risk of ultrasound-verified gallstones compared with control interventions.
The team observed that this effect was significantly larger in trials of diets alone than in trials of patients who underwent bariatric surgery.
UDCA reduced the risk of cholecystectomy for symptomatic stones.
The team noted that diets high in fat content also reduced gallstones, compared with those with low fat content.
The meta-analyses were confirmed in trials with a low risk of bias but not in sequential analysis.
No additional beneficial or harmful outcomes were identified.
Dr Lammert's team concludes, "On the basis of a meta-analysis of randomized controlled trials, during weight loss, UDCA and/or higher dietary fat content appear to prevent formation of gallstones."