What Are the Benefits and Risks of Alkaline Water?

Medically reviewed by Katherine Marengo LDN, R.D.
Written by Rena Goldman
Updated on May 30, 2019

What is alkaline water?

You may have heard various health claims about alkaline water. Some say it can help slow the aging process, regulate your body’s pH level, and prevent chronic diseases like cancer. But what exactly is alkaline water, and why all the hype?

The “alkaline” in alkaline water refers to its pH level. The pH level is a number that measures how acidic or alkaline a substance is on a scale of 0 to 14. For example, something with a pH of 1 would be very acidic and something with a pH of 13 would be very alkaline.

Alkaline water has a higher pH level than regular drinking water. Because of this, some advocates of alkaline water believe it can neutralize the acid in your body.

Normal drinking water generally has a neutral pH of 7. Alkaline water typically has a pH of 8 or 9. However, pH alone isn’t enough to impart substantial alkalinity to water.

Alkaline water must also contain alkaline minerals and negative oxidation reduction potential (ORP). ORP is the ability of water to act as a pro- or antioxidant. The more negative the ORP value, the more antioxidizing it is.

Does it really work?

Alkaline water is somewhat controversial. Many health professionals say there isn’t enough research to support the many health claims made by users and sellers. Differences in research findings may be related to the types of alkaline water studies.

According to the Mayo Clinic, regular water is best for most people. They state that there is no scientific evidence that fully verifies the claims made by supporters of alkaline water.

However, there are a few studies that suggest alkaline water might be helpful for certain conditions.

For example, a 2012 study found that drinking naturally carbonated artesian-well alkaline water with a pH of 8.8 may help deactivate pepsin, the main enzyme that causes acid reflux.

Another study suggested that drinking alkaline ionized water may have benefits for people with high blood pressure, diabetes, and high cholesterol.

A more recent study that included 100 people found a significant difference in whole blood viscosity after consuming high-pH water compared to regular water after a strenuous workout. Viscosity is the direct measurement of how efficiently blood flows through the vessels.

Those who consumed high-pH water reduced viscosity by 6.3 percent compared to 3.36 percent with standard purified drinking water. This means blood flowed more efficiently with alkaline water. This can increase oxygen delivery throughout out the body.

However, more research is needed beyond these small studies. In particular, research is needed to answer other claims made by alkaline water supporters.

Despite the lack of proven scientific research, proponents of alkaline water still believe in its proposed health benefits. These include:

- anti-aging properties (via liquid antioxidants that absorb more quickly into the human body)

- colon-cleansing properties

- immune system support

- hydration, skin health, and other detoxifying properties

- weight loss

- cancer resistance

They also argue that soft drinks, which are notoriously acidic, have very positive ORPs leading to many health problems, while properly ionized and alkalinized waters have highly negative ORPs. Green tea is rich in antioxidants and has a slightly negative ORP.