Medically reviewed by Allison Herries, RDN The alkaline diet is based on the idea that certain foods can change the body's pH (its measure of acidity and alkalinity) to reduce acidity. Though ...

"Theory behind drinking alkaline water for digestion is that the higher pH of the water lowers the pH of stomach acid (typically 1.5 to 3.5) and helps prevent or treat acid reflux," she said.