Most of us are now well versed in the connection between sugary beverages and cavities. We know that sodas and juices tend to have very high sugar content and that constant sipping will wreak havoc on oral health. Another factor that slid under the radar for years, but has recently gained more recognition is the acidic content of those same beverages. Sugar and acid work together inside the mouth to set up the ultimate destructive environment.
Here is a quick scientific rundown: pH is how we measure the acidity of any given environment. Lower pH numbers are more acidic while higher numbers are more alkaline. The average pH of saliva is 6.7, which is near neutral. One of saliva’s big jobs inside the mouth is to bring pH back toward neutral after eating or drinking something that altered the natural pH. Tooth enamel starts to break down when the pH drops below 5.5 (meaning the environment has become more acidic). When the pH drops below 3.0 we would consider that an extremely erosive environment. The enamel can be completely worn away by acid alone, but even a slight breakdown in the strength of enamel increases the risk for cavities to form. Normal salivary flow is responsible for re-balancing the oral environment. Anyone struggling with dry mouth, like people taking prescription medications or athletes whose salivary flow is decreased due to dehydration from high intensity workouts, will experience longer periods of acidity inside the mouth, making them more susceptible to erosion and decay.
Many beverages commonly consumed in the United States are highly acidic. Many sodas and juices have pH levels below 3.0, making them extremely erosive. Even more fall between 3.0 and 5.5, meaning they are acidic enough to begin the breakdown of enamel inside the mouth. As many Americans try to adopt healthier eating habits, they may choose more diet sodas, sports drinks, and water products. While those choices often lessen sugar consumption, they do not necessarily reduce the acidic content. Even bottled water can be surprisingly acidic!
The Journal of the American Dental Association published a pH study of a long list of beverages available in the US and here are some highlights from that study:
Sodas
Coca Cola – 2.37
Diet Coke – 3.1
Pepsi – 2.39
Mountain Dew – 3.22
Fruit Drinks
Lemon juice – 2.25
Ocean Spray Cranberry – 2.56
Minute Maid Apple Juice – 3.66
Kool-Aid Pink Lemonade – 2.66
Welch’s 100% Grape Juice – 3.38
Energy Drinks
Rockstar Energy Drink – 2.74
Monster Energy – 3.48
Redbull – 3.43
Tea and Coffee
Lipton Green Tea with Citrus – 2.93
Snapple Peach Tea – 2.94
Starbucks Medium Roast – 5.11
Sports Drinks
Gatorade Lemon-Lime – 2.97
Powerade Lemon Lime – 2.75
Powerade Zero Lemon Lime – 2.92
Vitamin Water Acai Blueberry Pomegranate – 2.98
Vitamin Water Zero Mixed Berry – 3.08
Water
Aquafina – 6.11
Dasani – 5.03
Perrier – 5.25
It might be surprising to see that sports drinks are pretty closely matched with sodas when measuring acidity. Some bottled waters also fall below the 5.5 threshold and can allow enamel to break down. Carbonated waters were not included in that particular study, but generally tend to be more acidic than flat water (though they do not match the acidity of sodas and sports drinks). Tap water here in the Bismarck/Mandan area has had an average pH around 9 over the past couple of years, making it an excellent choice when considering sugar content and pH of your beverage.
Choosing to drink water rather than sodas and sports drinks is an obvious way to reduce acid exposure inside your mouth. When you do choose to enjoy a more acidic beverage drinking it all at once with a meal rather than sipping it periodically between meals can help minimize damage. For most people it takes about 30 minutes for the saliva to re-balance the oral environment, so constant sipping will prolong the time the mouth stays at a low pH. It’s also important to use products that deliver fluoride in your daily oral hygiene routine, as fluoride helps re-mineralize your enamel. If you know that you have a lot of exposure to acidic foods or beverages talk to your dentist and dental hygienist about strategies to minimize damage to the teeth. They may recommend fluoride treatments in the dental office or have other tools and tricks to help!