To digest food, the stomach is flooded with acid. Between the stomach and the esophagus is a sphincter muscle that lets the food get to the stomach but then closes to keep the stomach acid from flowing back up the throat. If this muscle becomes loose or doesn’t work properly, the stomach contents can backflow into the esophagus, making it burn.

Or you can eat foods that are acidic themselves that can irritate tiny areas of irritation you already have on the walls of your esophagus.

The body tries to counter this not only with the sphincter, explains Liddle, but with saliva, which is alkaline. But sometimes these mechanisms are overcome by circumstance. Some factors that make heartburn more likely:

• Being overweight
• Smoking
• Lying down after eating
• Bending over after eating
• Pregnancy
• Certain medications
• Stress
• Wearing tight clothing
• Eating trigger foods

Summer Foods That Trigger Heartburn

Elaine Magee, MPH, RD, author of Tell Me What to Eat If I Have Acid Reflux and of a new DVD titled The Heartburn-Friendly Kitchen, tells WebMD that trigger foods vary from person to person.

“People tend to know,” Liddle says. “They will say, ‘I get heartburn every time I eat pizza.’”

Some real culprits that turn up time and time again are:

• Fatty meats and deep-fried foods (they stay in the stomach longer, giving acid more of a chance to wander)
• Citrus
• Chocolate
• Peppermint
• Excessive alcohol consumption (especially red wine)
• Tomatoes (salsa, catsup)
• Colas and coffee (caffeine and carbonation are both suspect)
• Orange juice
• Peppers
• Garlic and onions

Some of these weaken the hold of the sphincter and some scratch at irritation that is already there.

Other foods can bloat your stomach and force the acid back up your throat. These include carbonated beverages.

A good rule of thumb is not to eat greasy meals and foods that are already chockfull of acid.