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.
There are a few studies that suggest alkaline water might be helpful for certain conditions.
For example, a 2012 in vitro studyTrusted Source 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. However, more human studies are needed to explore these findings.
Researchers in Japan conducted a small 2018 studyTrusted Source that suggested that drinking alkaline electrolyzed water slightly improved stool in 60 participants.
A 2016 studyTrusted Source 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 had 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 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:
pro-aging properties (via liquid antioxidants that absorb more quickly into the human body)
immune system support
hydration, skin health, and other detoxifying properties