Relationship between fasting and acid reflux
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Fasting and Acid Reflux: Symptom Changes and Acid Exposure
Several studies have explored how fasting affects acid reflux, particularly in people with gastroesophageal reflux disease (GERD). Research on intermittent fasting, such as time-restricted eating, shows a mild reduction in acid exposure time and a noticeable improvement in symptoms like heartburn and regurgitation during fasting periods compared to non-fasting days. However, the reduction in acid exposure is weak statistically, and adherence to fasting regimens can be challenging for some patients . Similarly, studies on Ramadan fasting found that GERD symptoms, especially heartburn and regurgitation, significantly decreased after the fasting period, suggesting that fasting may help improve GERD symptoms for some individuals .
Acid Reflux Patterns During Fasting vs. Feeding
Research in both infants and adults indicates that acid exposure in the esophagus is generally higher during fasting periods compared to feeding periods. In preterm infants, the number of acid reflux episodes per hour and the percentage of acid exposure were significantly greater during fasting than during feeding, even though the total number of reflux events was higher during feeding (most of which were weakly acidic rather than strongly acidic) . In symptomatic infants, chemical clearance of acid reflux (the process by which the esophagus neutralizes acid) is significantly slower during fasting, which may contribute to prolonged acid exposure and symptoms .
Mechanisms and Contributing Factors
The relationship between fasting and reflux is influenced by several physiological mechanisms. During fasting, the efficiency of acid clearance in the esophagus is reduced, possibly due to decreased salivation, swallowing, and peristalsis, which are all stimulated by eating . Additionally, in healthy adults, duodenogastric reflux (the backflow of bile and digestive juices from the small intestine into the stomach) is cyclic during fasting and is linked to specific patterns of gut motility, but this does not necessarily translate to increased acid reflux into the esophagus 610.
Postprandial (After Eating) Acid Reflux
After meals, a highly acidic "acid pocket" can form at the gastroesophageal junction, which is not buffered by food and can contribute to postprandial reflux symptoms . In patients with delayed gastric emptying, postprandial reflux episodes are longer and more frequent, but the overall acid exposure during fasting remains significant . The speed of eating does not appear to significantly affect the number of reflux episodes, but acid reflux becomes more prominent in the hours following a meal .
Fasting and Laryngopharyngeal Reflux
In studies focusing on laryngopharyngeal reflux (LPRD), fasting was associated with a non-significant increase in LPRD symptoms and findings, such as throat clearing and globus sensation. The changes may be related to altered eating habits and gastric secretions during fasting periods, but the overall impact appears minimal .
Conclusion
Fasting tends to mildly reduce acid exposure and improve reflux symptoms in some individuals with GERD, though the effect is not strong for everyone. Acid exposure in the esophagus is generally higher during fasting than after eating, likely due to less efficient acid clearance mechanisms. While fasting may help some people with reflux symptoms, individual responses vary, and more research is needed to fully understand the underlying mechanisms and to identify which patients may benefit most from fasting as a lifestyle modification.
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