The background: Certain foods and ingredients can be bad for your digestion. Well, a new study shows just that! Fried foods, citrus fruits, fructose and peppermint, these are some of the more common types of foods that can cause indigestion. Doctor's expert insights The big picture: These foods can increase the amount of acid in your stomach, and some of these foods can actually loosen your esophageal sphincter. This is going to allow stomach acid to leak into your esophagus, your food pipe. Know this: If you've had heartburn for a long time, our doctors recommend that you get yourself checked for H. Pylori. Next steps: And this is what you need to know: too much acid in your food pipe can cause reflux and in some cases lead to diseases and cancer.