Consumption of water is essential to our overall good health and proper bodily functions. Every part of the body, from organs to individual cells, needs hydration to function and remain healthy. A Harris Poll showed that 82% of US adults recognize the importance of drinking proper amounts of water daily. Which then leaves the question: Is all water healthy? Specifically, is there a difference in the acidity of the water we consume, and does that difference impact dental health?

Generally, acidity is measured in pH (potential hydrogen ions). The pH scale goes from 1 (acidic) to 14 (alkaline), 7 being neutral. Each incremental numerical measurement of pH from1 to 14 represents a tenfold change in the acid/base properties, so a pH = 4 is ten times more acidic than a pH = 5. The pH in the mouths of healthy people ranges from 6.8-7.2 (neutral). Tooth enamel is the hardest part of our body due to its high calcium content. The dental health concern is that tooth structure breaks down in an acidic environment allowing for decay and erosion. The more acidic the environment, the faster the tooth breaks down. The more acidic the beverage, the more damage it can cause to our teeth. A study of the pH of almost 400 commercially available drinks in the US found that 93% had a pH of less than 4 (very acidic).

Nearly 100% of US adults believe that bottled water is healthier than carbonated beverages. Carbonated sodas pH ranges from 2.3-4.3, which is very acidic and not suitable for dental health. As a result, sales of bottled water continue to grow. In 2016 the sale of bottled waters (39.3 gallons/person) surpassed carbonated soft drinks (38.5 gallons/person) in annual sales volume. To further entice people to buy bottled water, many companies have added flavoring agents. These flavoring agents are usually sugar-free to appeal to low caloric intake diets but are generally highly acidic. The most common flavoring additive and preservative is citric acid (highly acidic). Although the Food and Drug Administration (FDA) regulates bottled water for safety, it does not weigh in on pH. Here are some examples of bottled water pH levels: Propel Zero 3.0, Vitamin Water 3.0, Dasani plain 5.0, Perrier 5.2, Aquafina 6.1, Arrowhead 6.8, Poland Spring 7.2, Fuji 7.3, Evian 7.4, Smart Water 7.6, and Essentia 9.4. As you can see, several brands of bottled water are neutral to alkaline pH level, which would be considered dental health. Still, there are also several that are very acidic, not dental healthy, buyer beware.

People may prefer bottled water to tap water due to the taste and smell of public utility water caused by additives such as chlorine. Tap water can be from a public water utility or well. Public water utilities are closely monitored for safety and are regulated by the Environmental Protection Agency (EPA); the pH is usually around neutral. Community water test results are published periodically. Well water is not regulated and should be tested every so often by the homeowner for safety and pH. Public water supplies are safe for teeth. Some people will add a small amount of lemon juice (citric acid) to their water to flavor it; this will significantly acidify the water, making it unsafe for teeth.

Recently, alkaline water has become popular for its purported but as yet unsubstantiated health benefits. Some believe that alkaline water can neutralize acids in the digestive tract and bloodstream. For dental health considerations, alkaline water is not harmful to the teeth and may help neutralize acids in the mouth. You can purchase bottled alkaline water or add alkylators to your home tap water.

The bottom line is drinking water is essential and healthful daily. Tap water may be a more reliable source of neutral pH than bottled water. When purchasing bottled water, check the ingredients, and avoid flavoring agents, especially citric acid.

Dr. Robert A. Gallegos is a Fellow in the Academy of General Dentistry, visiting faculty at Spear Education, an alumnus of Pankey Institute, a member of the American Academy of Cosmetic Dentistry, the American Academy of Dental Sleep Medicine and the American Dental Association. Dr. Gallegos practices dentistry in Middleburg, VA. www.MiddleburgSmiles.com.