In your school years, you must have read about acid-base chemistry. The whole concept of alkaline water is based on that theory. Advocates of ionized water, The Gout Code as it is often known, claim that the high pH of water helps in getting rid of acids in the bloodstream and can prevent a lot of common diseases.
Natural spring water is known to be alkaline and is often sold at high prices because of the same reason. Spring and stream water passes over rocks and gathers minerals, which changes the pH level. Of course, most of us don't live in the jungles, so we have to rely on packaged water, which comes with added things like calcium, magnesium, and bicarbonate. http://energizegreenssupplementreview.com/the-gout-code-book-review/