It’s been drilled into our heads for years: To slim down, eat less and exercise more. Yet a new study, published in the International Journal of Obesity, found that people can share similar diet, exercise, sleep and appetite hormone patterns yet lose weight at different rates: those who ate early in the day shed pounds more quickly than those who ate late. As earlier studies – including this one from last year – have also suggested, when you eat matters at least as much as what you eat.
Something similar applies to dental health. Consistently, nutritional advice emphasizes what to eat – and what to avoid – to keep your smile bright, healthy and whole. This is important. But just as important is, again, the when and how.
To understand this, let’s take a look at how cavities happen.
Your mouth – like your body as a whole – contains countless bacteria and other microorganisms. Some of these are beneficial; some, harmful. Good oral health comes from keeping this “oral flora” in balance, keeping the pathogens (the “bad bugs” that contribute to disease) from taking over, especially S. mutans and P. gingivalis, the main bacteria involved in tooth decay and gum disease. One way to do this is by brushing and flossing. Another is to limit or avoid things that help them grow and multiply, like sugars, their favorite food. When you eat it, they eat it.
And when they do, some interesting things happen.
For starters, through their metabolic processes, they generate a lot of acids. Conditions throughout the mouth are affected by this waste material, turning slightly acidic for a time. Saliva isn’t able to protect the teeth as effectively as usual. What’s more, the flow of fluids within your teeth is temporarily reversed. Normally, it flows outward, toward the enamel, repelling pathogens. When conditions turn acidic, it flows inward, actually pulling toxins into the tooth.
Over time, this becomes a disease process. The acids eat into the tooth enamel (and enamel, once gone, can never grow back), giving the microbes access to the dentin beneath. As this decay progresses, the lesion becomes mushy and spongy. A cavity doesn’t even look much like a hole until we clean out the rotten, diseased tissue prior to placing a filling.
That sugars spur this process isn’t the only reason why it’s wise to avoid – or at least limit – them, along with white flour products and other refined, fermentable carbs (all of which you digest as sugar). They also tend to stick to the teeth, giving the microbes even more opportunity to feast. Sweetened soft drinks repeatedly bathe the teeth in sugars (not to mention additional acids). The longer sugars remain in contact with the teeth, the greater the odds of decay developing.
This is why keeping regular mealtimes matters; why snacking or sipping sugared drinks through the day – “grazing” behavior – can wreak havoc on your teeth. Consider this anecdote from one of Dr. Glaros’ colleagues:
A woman brought her twin boys to us for their dental care. One of the boys had excellent teeth while the other had rampant caries (cavities). Yet both ate the same diet, which included a muffin a breakfast each morning. How each boy ate it made all the difference: the one with no caries ate his muffin all at once, while the other saved his to nibble from throughout the day.
Same diet. Different eating behaviors. Different outcomes.
Avoiding the temptation to graze will take you a long way toward keeping your teeth in good shape – as will forgetting the standard advice of brushing right after meals. Remember the acids? It takes about 20 to 30 minutes for saliva to fully neutralize them. Brushing during this time can actually contribute to tooth and gum problems, as you’re effectively brushing acid into the teeth.
Instead, wait a little while before brushing. And remember to floss.
In fact, go one better: floss first.