This article about alkaline diet is easy to understand:
Alkaline Diet: What to Know Before Trying It
http://www.webmd.com/diet/features/alkaline-diets-what-to-know
Mayo Clinic nutritionist answers a question about alkaline water:
Is alkaline water better for you than plain water?
http://www.mayoclinic.com/health/alkaline-water/AN01800
This article is a bit more advanced, but still quite understandable:
Acid/Alkaline Theory of Disease Is Nonsense
http://www.quackwatch.com/01QuackeryRelatedTopics/DSH/coral2.html
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My opinion:
Alkaline diet is mostly vegetarian diet so it’s basically a healthy diet. At the same time, it doesn’t have any magic properties to cure cancer. If you are going to follow this diet, buy regular food at the supermarket. No need to pay extra for “special” alkaline foods.
Alkaline water is a waste of money.