Wait, Before You Brush — Why Brushing your Teeth After Eating Could be Bad for You

By Mary Kay Kleist
April 2013 View more Health & Fitness

After a zesty meal, a cup of java, or a glass of wine, you may have the urge to brush your teeth. Believe it or not, that may not be the best idea. Some dental experts warn that all that extra brushing may do more harm than good.

Wait 30 Minutes

If you brush too soon after consuming an acidic drink or acidic food, you’re forcing the acid deeper into your teeth. Acids can damage your teeth. “Acidic foods and drinks soften the enamel and cause the teeth to demineralize. Brushing your teeth after this acid bath will accelerate the demineralization,” said Dr. Angelica Van Dyke, River Walk Family Dental in Naperville. She says acid wear is a problem she often sees in patients, especially now, with a growing generation of coffee and diet soda drinkers.

Examples of acidic foods and drinks include diet soda, wine, tomato-based foods like salsa, soups, pizza, and pasta sauce. Candy, cereal, and bread can also cause problems, if you brush too soon. “Eating or drinking acidic food and drinks accompanied by calcium, can reduce the effects of acid,” said Dr. Van Dyke. She says go for the calcium fortified orange juice. Also, eating a cup of yogurt can help minimize the acidic damage.

Breakdown of Tooth Structure

Each tooth has three layers. Enamel is the temperature protector. It’s the hardest surface in your body. Dentin is the middle layer. This layer is much softer than the enamel. When the acid hits this second layer, the cavity can spread a lot quicker because of the softer, more porous bone-like material. The third layer is the pulp, which contains blood vessels and the nerve. This soft layer supplies nourishment, sensory information and protection to the tooth. “The acid in foods and juices binds to calcium, which can be found in the enamel, dentin, and the saliva. When the calcium is removed from the saliva and enamel, it strips the tooth of its protection,” said Dr. Van Dyke.

When to Brush

In one study, researchers followed volunteers for 21 days, examining the impact of brushing on their teeth after they drank diet soda. The scientists found an increase in dentin loss when brushing within 15 to 20 minutes after consuming diet soda. But there was significantly less wear when brushing took place 30 or 60 minutes after drinking it.

We all like that fresh feel of clean teeth. If you just can’t wait 30 minutes, dentists say simply drinking water or chewing sugar-free gum will do the trick. This increases the amount of saliva. This constant bathing of the tooth will rinse away the acid and bacteria from your tooth naturally, as opposed to the mechanical effort of brushing the acid deeper into the tooth.

Exceptions to the Rule

Dental experts say foods that are sticky, like taffy and dried fruit, are the exception to the rule. You don’t want to wait to brush. In this case, the longer you wait, the better chance you have to develop cavities.

However, The American Dental Association still recommends brushing your teeth at least twice a day and flossing often. The ADA says there is not enough scientific evidence to warrant waiting a specific amount of time before brushing your teeth after consuming acidic foods or drinks.