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Abstract
Background: Gastroesophageal Reflux Disease (GERD) is a widely prevalent chronic condition. There is evidence to suggest an association between dairy consumption and symptoms of GERD, even though this is inconsistent and mostly based on observational studies. High dietary fat intake is also associated with symptoms of GERD; however, the current literature does not distinguish between different sources of dietary fat, which may include dairy fat. The purpose of this study was to investigate the impact of dairy consumption, and the fat content of dairy consumed, on the symptoms of GERD, specifically the frequency of acid reflux and the frequency and severity of heartburn, using data collected from a completed randomized controlled dietary intervention trial.
Methods: 72 participants with the metabolic syndrome were enrolled in this study. Participants first completed a 4-week wash-in diet period during which their dairy intake was limited to a maximum of 3 servings of skim milk per week. Participants were then randomized to either continue on the limited dairy arm, or switch to a diet containing an average of 3.3 servings per day of either low-fat or full-fat dairy products (milk, yogurt and cheese) for a 12-week period. A questionnaire was administered before and after the 12-week intervention to assess the frequency of acid reflux and the frequency and severity of heartburn experienced.
Results: In the per-protocol analysis (n=63), there was no effect of the dairy interventions on a cumulative heartburn score (p=0.443 for the time by diet interaction in the overall repeated measures analysis of variance). The dairy interventions similarly did not predict the odds of experiencing acid regurgitation in a binomial logistic regression model (p>0.2 for all three dietary intervention groups). Results were identical in the intent-to-treat analysis (n=72).
Discussion: This study suggests that consuming three servings of dairy per day, regardless of fat content, may not affect the common symptoms of GERD, heartburn and acid regurgitation, in men and women with the metabolic syndrome. These findings are limited because this was an exploratory analysis of data collected from a trial not designed to specifically study effects on GERD-related outcomes. To conclusively rule out a role of dairy foods in GERD, adequately-powered long-term intervention trials among participants who have been clinically diagnosed with GERD are warranted.
