What Causes Heartburn?

Heartburn, or what physicians call gastroesophageal reflux disease (GERD), is a source of severe discomfort to millions of Americans. It is also the number-one risk factor for the development of esophageal cancer. Acid reflux into the lower esophagus damages it. This leads to what is called Barrett’s esophagus, which is a precancerous state.Diet and lifestyle factors have long been blamed for GERD, but research to pin down the precise dietary factors responsible has been scant. The increasing prevalence of GERD is believed to be due in part to the growing number of overweight and obese people.1 The association between increasing body weight and GERD is even stronger in women than men.2 The increased pressure in the gut pushing the stomach contents up into the lower esophagus is most likely to occur when someone lies down after a large meal.Most people, including many doctors, blame coffee, tea, alcohol, aspirin and spicy foods for causing heartburn. However, a recent, large, controlled study found no support that these foods and drinks or the use of aspirin actually led to the development of reflux disease. According to this recent study, coffee and alcohol might play some role in promoting acute episodes of reflux, but they seemed unlikely to be playing a major role in the development of GERD. Tobacco has also long been suspected as making GERD worse, and this study confirmed those suspicions. The study showed those who had smoked 20 years or more were 70% more likely to suffer from severe GERD than those who never smoked or had not smoked in at least a year. Tobacco smoking almost certainly plays a causal role in the development of GERD.This study also found that a diet high in fiber-rich foods (particularly whole grains) and exercise were shown to significantly reduce the risk of severe GERD.3 The reduced risk of GERD with the consumption of more grain fiber is consistent with data showing those who eat more whole grains are less likely to develop cancer of the esophagus and upper stomach.4This was the first study to specifically look at the use of salt and the development of GERD. Perhaps the most surprising finding in this study (at least to the researchers) was that those who added salt to their food on a regular basis were 70% more likely to suffer from GERD than those who did not salt their food. In addition, those who ate more salted fish and meat products were 50% more likely to suffer from severe GERD than those who rarely or never ate those foods. The relationship between salt and salty foods and GERD increased with increasing salt intake in this study. The use of salt and the consumption of salty foods appear to be as likely to lead to GERD as smoking tobacco. If confirmed by other studies it appears that salt toxicity is a major cause of both stomach and now espohageal cancers.It may be premature to conclude from this one large study that salting food and eating salty meat and fish products leads to GERD. Even so, the evidence from this study strongly suggests excess salt is playing a major role in the development of GERD. The Institute of Medicine has set an adequate intake of salt at only 1,200-1,500 mg sodium per day because overwhelming evidence proves excessive salt intake is the most important causal agent in the development of hypertension.The Bottom Line: Those with GERD should be encouraged to lose excess weight, quit smoking, and reduce their intake of salt and salty foods as much as possible. They should be encouraged to eat more whole grains. Moderating alcohol intake and switching from coffee to tea may also help. This is good advice for those without GERD as well. Those with reflux should also be discouraged from lying down shortly after eating a large meal.By James Kenney, PhD, RD, LD, FACN.References:1 Am J Med 1999;106:642-92 Scand J Gastroenterol 2002;37:626-303 Gut 2004;53:1730-54 Gastroenterology 2001;120:387-91