Effects of Diet on Reflux and Dyspepsia

Reflux and dyspeptic symptoms are common affecting 10-20% of the population on a regular basis. Reflux symptoms such as heartburn and regurgitation are caused by the return of acid or non-acid gastric contents into the esophagus. Dyspeptic symptoms are caused by abnormal gastric relaxation (impaired accommodation) or increased sensitivity of the stomach to distension during the meal. The effects of diet on gastrointestinal function are debated and the efficacy of dietary management for digestive symptoms has not been established. Epidemiological studies suggest an effect; however, it is not possible to distinguish the effects of fat intake and total energy (i.e. calorie) intake in this work. This issue has been addressed by small physiological studies. The results show that esophageal acid exposure was related to total calorie intake but not to fat content. In contrast, the number of reflux symptoms was 40% higher after the high-fat than the low-fat meals. Similar findings were found for the relationship between gastric distension, fullness and dyspeptic symptoms by Magnetic Resonance Imaging. Thus, it appears that fat does not cause digestive dysmotility but heightens sensitivity to visceral events and so increases the number and severity of symptoms reported by patients. As yet, these findings have not been confirmed in larger, more representative surveys. Similar to the effects of food, there are inconsistent findings regarding the effects of alcohol on gastro-esophageal reflux (GER) and gastric function. Physiological studies have noted delayed gastric emptying and an increase in reflux events when alcohol is taken with food. However, larger surveys have not confirmed that alcohol triggers reflux or dyspeptic symptoms. The proposed observational, dietary study with cross-over design will assess the independent effects of energy intake (i.e. calorie load) and fat intake on gastric fullness, the number and severity of reflux and dyspeptic symptoms after meals.