Heartburn Trigger: Acidic Foods

Acidic foods -- which include tomatoes and products that contain tomatoes (such as tomato sauce and salsa) and citrus fruits (such as oranges, grapefruits, and lemons) -- can trigger heartburn, especially if you eat them by themselves, on an empty stomach. Vinegar is also highly acidic -- not that you're going to eat vinegar by itself, but it's a common ingredient in salad dressings and other dishes.