Having a glass of wine a day may lower the risk of developing a disorder called Barrett's esophagus, a condition of the lining of the passage running from the mouth to the stomach that can become cancerous, investigators report.

Exactly how wine might achieve this beneficial effect is unclear, Dr. Al Kubo, from Kaiser Permanente, Oakland, California, and colleagues note in their report in the medical journal Gastroenterology.

Wine contains certain compounds that could reduce damage to the esophagus. Alternatively, drinking wine could represent a proxy for some other lifestyle factor that has a beneficial impact.

The findings come from a study comparing 320 patients with Barrett's esophagus to a similar number of people with other conditions as well as healthy individuals. Dietary information was collected with validated questionnaires given during in-person interviews.

The researchers found that overall alcohol use was not significantly associated with Barrett's esophagus. However, wine specifically did have a protective effect.

Compared to people who did not drink, those who drank seven or more glasses of wine per week were 66 percent less likely to develop Barrett's esophagus.

Higher education was also linked to a lower risk, Kubo and colleagues found. They say future studies should look into the effects of vitamin supplements and alcohol types, and how socioeconomic status may affect the risk of developing Barrett's esophagus.