I recently saw a sign at my local convenience store that read "Alkaline Water Sold Here." My first thought? "What a scam." Water is water, right? For me, the only deciding factor in choosing a bottle of water is the packaging or the price. But being a dietitian, I started to wonder about the science behind alkaline water. What makes one variety of water more alkaline than others, and is it really any better for you than regular old tap water?
Acid vs. Alkaline
First, let's start with a short science lesson. The pH scale measures the acidity of a substance, and it ranges from 0 to 14, with 0 being the most acidic and 14 being the most alkaline. If a pH is greater than 7, the food is considered alkaline. Most distilled water has a pH of 7, while lemon juice has a pH of 2. Alkaline water is rich in alkalizing minerals, like calcium, potassium, and magnesium, which make it less acidic than tap water, with a pH above 7.
Some studies suggest that eating an excess of acid-forming foods (like meat, caffeine, and sugar) causes the body to pull alkalizing minerals—like calcium—from the bone to neutralize the blood, which weakens the bone. Another popular theory is that eating acidic foods may cause inflammation, which, in turn, causes illnesses like cancer. With all this fear of acid in the body, many are turning to alkaline water with a pH of 8 or higher.
Can Alkaline Water Reduce Acid in the Body?
Alkaline water is advertised as being able to neutralize some of the acid in the body, decreasing some negative health effects. But the body's pH is tightly regulated by many internal systems, and after food is digested, it travels into the stomach where it is broken down by natural acids. It then leaves the stomach and travels to various organs as an acidic bodily fluid. No level of alkaline water will change these body mechanisms, so downing the stuff for that purpose is pretty much a wasted effort.
Are There Any Health Benefits?
Although you can't change the body's internal pH, you may be able to score some health benefits from drinking alkaline water—especially if you're an elite athlete. Working out at your max capacity (think sprinting until you can't run anymore) creates more hydrogen ions than normal exercise, which causes a buildup of lactic acid and fatigue. One study showed that drinking alkalized water may help reduce the buildup of lactic acid and cardiorespiratory stress. Many believe that it's not the pH of the water that creates the athletic benefits, but the mineral supplementation. For example, a magnesium deficiency can increase the amount of oxygen the body needs, making exercise feel more difficult. Adding minerals into the water helps counteract these effects.
The Bottom Line
Unless you're a competitive athlete, there's no real need to drink alkaline water. Regular tap water will hydrate you just fine and save you a couple of bucks. A better idea? Vegetables are some of the most alkaline foods you can eat to neutralize acid. You will get much more nutrition bang for your buck with veggies than with alkaline water.