Why not to brush your teeth after you eat
It may seem contrary to common sense, but brushing right after a meal may do more harm than good.
Tue, Sep 17, 2013 at 12:43 PM
Whether you are a diligent brusher of the teeth right after eating, or if you’re like the rest of us and feel a tinge of shame for not doing so, you may be interested in knowing this: at least one study has shown that the practice is not in the best interest of your pearly whites.
While some professional opinions vary, a number of top teeth docs agree with the findings. The basic problem is that the sugar in foods is metabolized by the bacteria or plaque on enamel, producing acids that lead to gum disease and cavities.
Common sense suggests that brushing the food particles away as quickly as possible would reduce the problems; but such is not the case.
Dentist Jeffrey M. Cole, former president of the Academy of General Dentistry, a dental advocacy group, told the Wall Street Journal, "What we found is that much of the cariogenic substances, those things that cause cavities, are not only sugar-containing, but they are very acidic themselves."
The perfect pH for the mouth is seven, and when you consume something acidic, the pH drops. Even a diet soda can have a pH as low as 2.5 — similar to vinegar — and it can take a while for the mouth to return to a normal level. Acid weakens the surface of the tooth, which can invite decay.
So when it comes to brushing your teeth when the mouth is in an acidic state, it actually exacerbates the problem.
"When you want to make etched glass, you apply an acid or an abrasive and scratch it – that is what happens if you drink a sports drink or a soda, or even wine, and brush right after," says Cole. But if you give your mouth some time – around a half an hour – your saliva will have worked to neutralize the acids.
There are some things that can be done to help instead of immediate brushing. Both rinsing your mouth with water or using an antibacterial mouthwash, Cole suggests, can help balance the pH and prevent plaque from creating more acids.
Chewing sugarless gum is also recommended as some studies have shown that the sweetener, xylitol, has benefits for the teeth. But perhaps the more satisfying option? Eat cheese. Oddly enough, chewing cheese reduces the pH of bacterial plaque. Cole explains that chewy things encourage salivation and proteins in your saliva will buffer acids; as well, naturally occurring chemicals in cheese "encourage the tooth to remineralize."
So the next time your colleague at the office heads to the bathroom to brush his teeth after lunch, you can now smugly assuage your guilt by breaking out a hunk of cheese instead.
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