Dietary fiber, defined as edible but nondigestible carbohydrate-based material, is available naturally in many plants, vegetables, cereals and grains, playing an important role in gastrointestinal health. The average American is deficient in fiber, which includes both the soluble and insoluble types. Soluble fibers tend to slow digestion, while insoluble fiber may speed the transit of foods through the gastrointestinal tract. The science is unsettled on acid reflux, but theoretical benefits from adequate intake of fiber include avoiding trigger foods, the stomach-filling effect of fiber and less relaxation of the anti-reflux valve between the stomach and esophagus.
Fiber and Acid Reflux Triggers
Soluble fiber causes the body to draw fluid from digested food, which contributes bulk to meals, leaving you feeling more satisfied for longer. Found in sources such as oat bran, barley and peas, soluble fiber also serves in regulating glucose, a type of sugar, and may help to signal the brain that the stomach is full during and after eating. Smaller meals help reflux by not overfilling the stomach. Insoluble fiber such as in vegetables and whole grains may serve to speed the passage of stomach contents to the intestines, decreasing the opportunity for reflux.
Fatty, fried foods are usually low in fiber and are frequently associated with triggering symptoms of regurgitation, indigestion and heartburn. Thus, a diet rich in fibrous foods like fresh fruits and vegetables and whole-grain breads may contribute to lower incidence of reflux symptoms.
Specific Sources of Fiber
Some dietary fibers are also considered prebiotics. Probiotics refers to the helpful bacteria themselves, while prebiotics refers to bacterial nutrients. Prebiotics are nutrients that are left for bacteria to digest -- essentially fuel to encourage balanced bacterial growth in the digestive organs. This represents another theory as to how specific dietary fibers might play a role in improving acid reflux symptoms -- through some sort of bacterial intermediary. Overall, however, specific dietary items seem to play a relatively minor role in chronic acid reflux. People suffering from acid reflux are encouraged to avoid specific foods that aggravate heartburn and regurgitation, but arbitrary elimination of foods is not recommended. Taking note of foods and beverages that seem to trigger reflux is preferred.
Evidence for Fiber Benefits
One study involving 65,363 people and published in the journal “Gut” in April 2004 showed that fiber intake was significantly associated with improved perception of reflux symptoms. This study also found that those who ate bread with higher fiber content were twice as likely to experience relief of reflux symptoms as those who ate bread with lower fiber content. The reasons for these observations are unknown, but the authors speculated something about the process of digesting fiber may also lead to less smooth muscle relaxation from the stomach to esophagus, essentially tightening the anti-reflux valve.
Disadvantages of Fiber in Reflux
While fiber can be beneficial in helping to alleviate acid reflux, too much of it can further aggravate the problem. An April 2013 study published in “The American Journal of Gastroenterology” showed that a diet including at least 10 grams of highly fermentable starches per day may significantly contribute to reflux episodes. Another study from the April 2003 edition of “Gastroenterology” noted that of nine participants diagnosed with gastroesophageal reflux disease, or GERD, those who routinely consumed a type of prebiotic known as fructooligosaccharides had significantly higher reports of reflux symptoms than those who took a placebo.
Fiber, Reflux and the Bigger Picture
Dietary fiber is one of many aspects to consider in successfully managing reflux symptoms. For example, being overweight and being obese are risk factors in GERD, and adequate fiber consumption helps keep weight in check. Supplemental fiber, however, can cause stomach distention, increased stomach pressure and prolonged stomach emptying -- all of which can lead to worsened acid reflux. Clinical practice guidelines published in the October 2013 "American Journal of Gastroenterology" recommend making lifestyle changes such as eating frequent, smaller meals and limiting your consumption of carbonated beverages and salted foods as part of a collaborative approach to help improve reflux symptoms.
Medical advisor: Jonathan E. Aviv, M.D., FACS