Dietary intake and the risk of gastro-oesophageal reflux disease: a cross sectional study in volunteers.

BACKGROUND: Although diet has been associated with gastro-oesophageal reflux disease (GORD), the role of dietary components (total energy, macro and micronutrients) is unknown. We examined associations of GORD symptoms with intakes of specific dietary components.
METHODS: We conducted a cross sectional study in a sample of employees (non-patients) at the Houston VAMC. The Gastro Esophageal Reflux Questionnaire was used to identify the onset, frequency, and severity of GORD symptoms. Dietary intake (usual frequency of consumption of various foods and portion sizes) over the preceding year was assessed using the Block 98 food frequency questionnaire. Upper endoscopy was offered to all participants and oesophageal erosions recorded according to the LA classification. We compared the dietary intake (macronutrients, micronutrients, food groups) of participants with or without GORD symptoms, or erosive oesophagitis. Stepwise multiple logistic regression analyses were used to examine associations between nutrients and GORD symptoms or oesophageal erosions, adjusting for demographic characteristics, body mass index (BMI), and total energy intake.
RESULTS: A total of 371 of 915 respondents (41%) had complete and interpretable answers to both heartburn and regurgitation questions and met validity criteria for the Block 98 FFQ. Mean age was 43 years, 260 (70%) were women, and 103 (28%) reported at least weekly occurrences of heartburn or regurgitation. Of the 164 respondents on whom endoscopies were performed, erosive oesophagitis was detected in 40 (24%). Compared to participants without GORD symptoms, daily intakes of total fat, saturated fat, cholesterol, percentage of energy from dietary fat, and average fat servings were significantly higher in participants with GORD symptoms. In addition, there was a dose-response relationship between GORD and saturated fat and cholesterol. The effect of dietary fat became non-significant when adjusted for BMI. However, high saturated fat, cholesterol, or fat servings were associated with GORD symptoms only in participants with a BMI >25 kg/m2 (effect modification). Fibre intake remained inversely associated with the risk of GORD symptoms in adjusted full models. Participants with erosive oesophagitis had significantly higher daily intakes of total fat and protein than those without it (p<0.05).
CONCLUSIONS: In this cross sectional study, high dietary fat intake was associated with an increased risk of GORD symptoms and erosive oesophagitis while high fibre intake correlated with a reduced risk of GORD symptoms. It is unclear if the effects of dietary fat are independent of obesity.