DEAR MAYO CLINIC: I’ve heard that alkaline water is better at rehydrating your body than nonalkaline, or plain, water. Is this true?
ANSWER: In short, for most people, plain water is better. But first, it’s important to understand the definition of alkaline water. Scientists use pH to describe how acidic or basic a substance is, with a range from 0 to 14. Pure water has a pH of 7, meaning it’s neutral. Fluids with a pH under 7, such as coffee and soda, are acidic. Substances with a pH over 7, such as baking soda, are basic, or alkaline.
Alkaline waters have a pH around 8 or 9. Some vendors use water that has a naturally higher pH, while others say that they create alkaline water through an ionization process.
Alkaline water companies make a host of claims, saying it’s better at rehydrating the body, and that it will detoxify and “balance” your body, help you lose weight, and prevent or even treat cancer. However, there’s little credible research showing that alkaline water benefits your health in any important way. In general, be wary of promoted research on alkaline water, as some of these studies are small or funded by alkaline water companies.
Some studies also suggest that alkaline water might help slow bone loss, but further investigation is needed to determine if this influences overall bone mineral density and if the benefit is maintained over the long term.
Often, claims about the benefits of alkaline water rest on the argument that modern diets make our bloodstreams and bodies too acidic. This is misleading. Regardless of what you eat or drink, your body is good at regulating your blood pH through organs such as your lungs and kidneys. It’s possible to have excess acid in your body fluids — what is known as acidosis — but this is generally caused by a serious condition such as a chronic disease involving the lungs or kidneys.
Many people don’t drink enough water, and they may feel better after increasing hydration through alkaline water. However, it’s probably not the alkaline nature of the water that’s of benefit. It’s the water. You can save money and hydrate your body perfectly fine simply by drinking plain water. — Katherine Zeratsky, RDN, Endocrinology/Nutrition, Mayo Clinic, Rochester, Minnesota