Why Brushing Teeth After Eating Is A Bad Idea

Why Brushing Teeth After Eating Is A Bad Idea

 Whitney DiFoggio BS, RDH
Written by Whitney DiFoggio BS, RDH🔬 Evidence Based
 Why Brushing Teeth After Eating Is A Bad Idea

Did you know that it might actually be a bad idea to rush straight to the bathroom and brush your teeth right after you eat something? All this time you’ve probably thought, “I need to brush my teeth the second I finish eating or right after I drink a soda.” In reality, there should be some buffer room between eating, snacking, drinking, and brushing your teeth. And there’s a good reason why: acid erosion. Knowing exactly how long to brush teeth after eating can mean the difference between enamel erosion and a healthy, strong smile.

Why Wait?

Every time we eat or drink something, natural harmful bacteria in our mouths break those food particles, sugars, and carbohydrates down for digestion. As a result, they secrete an acidic byproduct. This acid secretion process lasts for approximately 30 minutes. If you were to go straight to the sink to brush your teeth right after you drank a soda, ate a cookie, or had acidic foods, you’d effectively be scrubbing around all of the sugars and acids across your teeth. And that’s actually worse than not brushing at all.

Feel like you can’t win for losing?! Thankfully there’s a smart way to brush your teeth, but the key is to remember how long to wait to brush after eating or drinking something. As a general rule, it’s about half an hour. That’s how long it takes for all of those acids to neutralize themselves and stop eating away at your teeth, and for your tooth enamel to remineralize on its own. Once the acids start to die off, you can go in with your toothbrush to remove the leftover plaque and food particles.

How Long To Brush Teeth After Eating

Don't start brushing immediately after eating a meal. It’s best to wait for about 30 minutes after eating or drinking (anything other than water) before you brush your teeth. Especially if it’s something acidic like orange juice or soda! This good half hour gives your tooth enamel a chance to remineralize itself with the enzymes and proteins in your saliva, before you go and scrub all of the sugars around across all of your teeth.

On a side note, the same 30-minute rule also applies to if you’ve thrown up, because of the stomach acids.

While it might seem counterintuitive, you don’t have to wait to rinse your mouth out with water. In fact, rinsing with tap water can help lower overall acid levels inside your mouth without physically “scrubbing” them around like a toothbrush would. While rinsing doesn’t replace toothbrushing, it can give you a jump-start when it comes to combatting cavities, acid erosion, and sensitive teeth if you’re eating or drinking anything with a low pH level. It might even help freshen up your breath a bit in the meantime!

If I Leave Food There For 30 Minutes, Will It Start Tooth Decay?

It’s hard to wrap your mind around the idea of not brushing your teeth if you ate something that could potentially cause cavities. Like candy,  sugar, or any acidic foods. It’s sort of a lesser of two evils situation. One, you could physically remove the leftover food, but doing so would scrub the sugar and acid around more, or two, you could allow it to sit there and neutralize itself, then go back and remove it with a toothbrush.

As long you’re not constantly sipping or snacking all day long, your teeth are made to withstand some semi-regular acid exposure. But if it’s dragging on every afternoon or all morning (think 3-4 cups of your favorite flavored coffee) then you’re getting a ton of acid exposure without any breaks. How to brush your teeth, tackle morning breath and eat breakfast is another topic you can learn more here!

Hypothetically, you’ll have a way higher risk of acid erosion and cavities if you’re snacking a little here and there every day, rather than eating a load of candy all at one time. The important thing is to give your mouth a break from sugars, carbs, and acids. Waiting 30 minutes to brush your teeth after eating isn’t nearly as “bad” for your teeth as having multiple snacks throughout the day.

Do I Have To Brush After Every Meal?

No, you don’t. It’s important to brush at least twice a day—preferably in the morning and at night before bed—to remove plaque biofilm before it calcifies into tartar. Regular, effective toothbrushing will help prevent both cavities and gum disease.

If you’re looking for other ways to freshen your breath mid-day when you don’t have a toothbrush, you can:
  • Rinse with an alcohol-free essential-oil based mouthwash
  • Use a tongue scraper
  • Rinse your mouth with water right after you eat
  • Chew a piece of xylitol-sweetened gum

Will it kill you to brush your teeth right after a meal every once in a while? No. But you don’t want to make a habit of it, as it will contribute to acid erosion if it’s an everyday ordeal.

While brushing twice a day is the minimum to aim for, brushing 30 minutes after every meal is even better. For those of us who can brush during our lunch break or work from home, this is usually a no-brainer.

How To Brush The Right Way

Always brush with a fluoride toothpaste. Fluoride helps remineralize weak tooth enamel, which is super important after eating anything sweet or acidic. You only need a pea-sized amount of toothpaste to do fight plaque causing bacteria. Yep, really.

The American Dental Association recommends brushing your teeth twice daily using a fluoride toothpaste and toothbrush, spending a full two minutes each time.

Make sure you’re brushing for a minimum of two minutes at a time. That’s 30 seconds per “quadrant” of your mouth: upper right, upper left, lower right, and lower left. If you aren’t timing yourself, you’re probably only brushing 30-45 seconds total across your entire mouth. That’s why electric toothbrushes with built-in timers are always a great idea.

If you struggle with this, you need to check out the BetterMouth program to help you develop the best possible home care routine!


As you brush, try to angle the bristles toward your gums, where the plaque tends to be the thickest. Make short, gentle strokes across 1-2 teeth a time as you work your way throughout your mouth.

How To Floss The Right Way

Brushing only cleans about 60% of your tooth surfaces. To clean the other 40%, you need to make sure you’re flossing every day. Wrap the floss around your tooth, glide it up and down—allowing it to gently slip under the gums—and then repeat the process around every tooth, every day. Or toss the floss and use a water flosser instead!

Talk With Your Dentist 

If you have trouble with recurring cavities, acid reflux disease, or scenarios that predispose you to a lot of acid erosion on your teeth, brushing more often isn’t the answer. Ask your dentist about getting a prescription fluoride gel or rinse to use at home. Be sure to schedule regular checkups too, so that your dental team can screen for new areas of concern while they’re still smaller and easier to manage.

Brushing Teeth After Eating Recap

Don’t rush off to brush your teeth immediately after you drink or eat something. Instead, wait at least 30 minutes. That half hour will allow the acids to settle down, your tooth enamel to remineralize, and prevent you from scrubbing everything around your teeth with your toothbrush (essentially making the acid erosion even worse.) You can always rinse your mouth out with water if you want to. Limit snacking throughout the day, as frequent sugar and carb exposure will increase your risk of cavities, regardless of how often or when you’re brushing. Aim for brushing twice a day, minimum, and always with a fluoride toothpaste.  

 Whitney DiFoggio BS, RDH
Written by Whitney DiFoggio BS, RDH"Teeth Talk Girl," is a registered dental hygienist. She started her dental health journey on YouTube, educating the public through videos.
Last updated onOctober 9, 2023Here is our process

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