One of the reasons dentists and other health professionals recommend drinking water over other beverages is because water is not typically acidic.
Excess acid in the diet can contribute to dental health concerns including enamel erosion and tooth decay, as well as heartburn, acid reflux, acidosis and other systemic health problems. As bottled waters have surged in popularity, so has concern about their pH properties. In fact, increasing evidence indicates that many bottled waters are nearly as acidic as some sodas and energy drinks.
The pH Balance
Substances that register a pH of less than 7 are considered acidic, while 7 is neutral. Substances with a pH greater than 7 are referred to as basic or alkaline. A 2015 study tested 14 bottled waters, including two that marketed themselves as alkaline with a pH above 8. For comparison, two samples of tap water from different municipal systems were also tested.
Most of the waters were acidic, and two were indeed alkaline. Only the tap waters had a neutral pH of 7, the same as pure water.
The study’s findings, which were published in the June 2015 edition of the Journal of Dental Hygiene, included this concerning note: “The majority of waters tested had a more acidic pH when tested in the lab than the value listed in their water quality reports.” In other words, you can’t necessarily trust what the labels tell you about acidity.
Bottled Water vs. Other Beverages
The pH of many popular bottled waters ranges from about 3.5 to 6.5. For comparison, coffee generally checks in between 4.5 and 5, and fruit juices range from about 3 to 4.5. Many sodas and energy drinks register a pH between 2.5 and 3.
Despite the proximity in pH levels, it’s unfair to compare bottled water to fruit juice and soft drinks. With the exception of some flavored waters, most bottled waters do not contain sugar, which most juices, sodas and energy drinks include by tens of grams, and which is a major contributor to dental plaque and cavities.
While there is not yet significant research that shows bottled water may lead to acid-related problems, there is some circumstantial evidence. A 2010 report by an ABC News affiliate focused on a man who suffered heartburn and gout, two conditions related to acid buildup. When medication didn’t work, the man and his physician discussed the possibility of the nearly gallon of bottled water the man consumed daily; the man switched to tap water and his symptoms improved.
Why is Some Bottled Water Acidic?
Many bottled waters naturally contain more minerals than tap water or have minerals added in the purification process, both of which can enhance their acidity.
As a 2015 Daily Mail article about bottled water noted, water that comes from deep aquifers may contain silica, potassium, sodium and other minerals that can affect the water’s pH. Exposure to air during the bottling process can also impact the chemical makeup and pH of the water.
Water—even bottled water—is still your best beverage choice. But tap water remains the top option, and if you drink a lot of bottled water and begin to notice symptoms such as heartburn or upset stomach, it’s a good idea to make at least a temporary switch and talk to a health professional.
Austin dentist Dr. Dan Matthews is dedicated to providing cosmetic dentistry services that enhance the appearance of your smile and your oral health. To learn more or schedule your consultation, please call our Bee Cave Road office at 512-452-2273.