The impact of low-fat and full-fat dairy foods on symptoms of gastroesophageal reflux disease: an exploratory analysis based on a randomized controlled trial

Purpose Gastroesophageal reflux disease (GERD) is a widely prevalent condition. High consumption of dairy foods and dietary fat are associated with worse GERD symptoms. However, existing data are inconsistent and mostly based on observational studies. The purpose of this exploratory analysis of a randomized controlled trial was to investigate the impact of low-fat and full-fat dairy food consumption on GERD symptoms. Methods Seventy-two participants with metabolic syndrome completed a 4-week wash-in diet during which dairy intake was limited to three servings of nonfat milk per week. Participants were then randomized to either continue the limited dairy diet or switch to a diet containing 3.3 servings per day of either low-fat or full-fat milk, yogurt and cheese for 12 weeks. Here, we report intervention effects on the frequency of acid reflux, and the frequency and severity of heartburn, exploratory endpoints assessed by a questionnaire administered before and after the 12-week intervention. Results In the per-protocol analysis ( n = 63), there was no differential intervention effect on a cumulative heartburn score ( p = 0.443 for the time by diet interaction in the overall repeated measures analysis of variance). Similarly, the intervention groups did not differentially affect the odds of experiencing acid regurgitation ( p = 0.651). The intent-to-treat analyses ( n = 72) yielded similar results. Conclusion Our exploratory analyses suggest that, in men and women with the metabolic syndrome, increasing the consumption of either low-fat or full-fat dairy foods to at least three servings per day does not affect common symptoms of GERD, heartburn and acid regurgitation compared to a diet limited in dairy. Clinical trial registration ClinicalTrials.gov Identifier: NCT02663544, registered on January 26, 2016.