Brushing before bedtime is the most important brushing session of the day. Failing to brush before bed means bacteria lingering in your mouth after your evening meal will remain overnight, feeding on residual sugars and creating plaque as a harmful by-product that destroys your teeth and gums.

But that’s not all - eating after brushing has several other consequences for your oral health.

What happens when you eat after brushing before bed time?

• Plaque build up

• Lactic acid build up

• Bad breath

At some point, we will all have reached for a snack after brushing our teeth. However, this isn’t something you should do regularly, especially if it’s anything remotely sugary.

When you leave residual sugar in your mouth, bacteria have a field day gorging on these sugars. In the process, they double in size every 20 minutes and produce lactic acid and plaque, which are harmful to your tooth enamel and gum tissue. 

Whilst lactic acid does its dirty work lowering the pH level in your mouth (creating a destructive high-acid environment and rendering your enamel vulnerable to cavities), plaque gets up to its machinations by suffocating your gum tissue and causing the onset of gum disease, including gum recession, bleeding gums and pockets in your gum tissue.

Bacteria can then access the bone underneath and gums, gradually attacking and eroding these vital supporting structures.

By understanding the consequences of eating after brushing, you can make informed decisions about your oral health, and hopefully find the motivation to stop.

Why you shouldn’t eat after brushing  

It weakens the cleaning effects of toothpaste

Your nighttime brushing session is essential for preventing bacteria from wreaking havoc on your teeth. Toothpaste is an armour for our teeth while we sleep, protecting it, but it also repairs damage sustained during the day (which is why you shouldn’t rinse before brushing as this dilutes its effects).  

Your toothpaste also plays a helping hand in removing sugar that has built up during the day, and preventing it from causing erosion, whilst diluting the acid within the sugary and high-carbohydrate foods you’ve consumed. But – it needs time to do this.

In order to get the full cleaning effects of your toothpaste, you should not eat after your evening brushing session.

Reduces the impact of fluoride

The fluoride in your toothpaste reduces cavities, remineralises your enamel and prevents the growth of cavity-causing bacteria.

When you eat shortly after brushing, you rob fluoride of the opportunity to offer this protection. Fluoride generally needs around 30 minutes to work its magic, so as well as refraining from eating before bed, don’t drink any liquids that will wash away its effects during this time (including water) if you can.

Causes bad breath

It’s no surprise that by leaving food stuck in between your teeth overnight, you invite bad breath, especially if it’s odour-rich foods like onion or garlic.

These foods rot away in your mouth all night long because the flow of saliva isn’t there to rinse them away (we produce far less saliva when we sleep than when we are awake). The longer these food particles are allowed to stay, the fouler the smell they produce.

The takeaway

• Eating after brushing pierces a big hole in the armour your toothpaste and brushing provides. Not only this, but if you’ve gone to all the effort of brushing and flossing, only to undo this with a snack, you’re wasting all the hard work you’ve put in to keep your teeth safe overnight.

• If you do have the occasional night where you find yourself eating after brushing and you can’t or don’t want to brush again, gargle some water to dislodge the food particles. This will also help to banish some of the sugars, and neutralise some of the acids in your mouth.

• This said, we never recommend eating after brushing if you can help it. 8 hours is all it takes for plaque to start proliferating significantly, and that’s bad news for your teeth