Pineapple and many other fruits should already be included in your weekly diet, but if you are struggling with heartburn, formally known as high acidity, then these fruits are even more important. Pineapples, in particular, possess high concentrations of vitamin C and other antioxidants that can function as anti-inflammatory and stomach-balancing compounds. If you want to lower acidity in the stomach, and prevent that burning sensation in your chest following a spicy meal, be sure to make pineapple a part of your diet.