Scientists have discovered that a certain compound produced in the body after eating foods like pomegranates, walnuts, and some berries — known as urolithin A — improves heart function by up to 80% in a type of heart failure that has limited treatment options. The specific type of heart failure investigated is known as heart failure with preserved ejection fraction (HFpEF). While the heart can still pump blood during this condition, it becomes stiff and does not fill properly, meaning that heart failure treatments are less effective.