People who smoke or use high amounts of table salt on their food appear to be at increased risk for gastroesophageal reflux, a disease in which stomach juices flow back into the esophagus, European researchers report. In contrast, tea and alcohol, which have been identified as culprits in past studies, did not increase the risk.

Gastroesophageal reflux is best known as a cause of heartburn. However, if severe and untreated, the condition can raise the risk of esophagus cancer.

Although the problems that can arise with gastroesophageal reflux are well documented, little is known about what actually causes the condition, lead author Dr. M. Nilsson, from the Karolinska Hospital in Stockholm, and colleagues note. Previous studies have looked at lifestyle habits as a possible cause, but many have been unable to reach firm conclusions due to insufficient numbers of patients.

To address the size issue, Nilsson’s team used a large study group - 3,153 people with symptoms of reflux and 40,210 people with no reflux symptoms. The researchers’ findings appear in the medical journal Gut.

The risk of gastroesophageal reflux increased as the number of years smoking rose. Compared with non-smokers, people who smoked for 1 to 5 years were 20 percent more likely to develop reflux, while people who smoked for longer than 20 years were 70 percent more likely.

As noted, high salt intake also increased the risk of reflux. People who always put extra salt on regular meals were 70 percent more likely to develop reflux than people who never used extra salt. Also, eating meals of salted fish or meat more than twice a month increased the risk by 50 percent compared with never eating such meals.

Certain lifestyle habits seemed to reduce the risk of reflux, such as eating bread high in dietary fiber and frequent exercise. Surprisingly, coffee intake, which has been tied to an increased risk of reflux in some studies, was actually linked to a decreased risk. However, the authors believe that the beverage may not really protect against reflux, rather patients with reflux simply avoid drinking coffee.

“Tobacco smoking and table salt intake seem to be risk factors for gastroesophageal reflux symptoms,” the authors conclude. In contrast, dietary fibers and physical exercise seem to protect against the condition, they add.

SOURCE: Gut, December 2004.