Your fruit smoothies are chock-full of vitamins -- as well as sugar and acid. When you combine multiple fruits into a single drink, you get way more sugar than you would if you were to eat fruit individually.

"Juices can have more sugar than soda," says Lituchy. "Bacteria convert the sugar to acid, which can wear down the enamel and cause cavities." That's not-so-sweet news for folks who coat their teeth with sugar-heavy smoothies on a daily basis.

To lessen the damage, Lituchy suggests drinking smoothies through straws, which help funnel sugars away from the surface of the teeth, and consuming them quickly so that you're not continually bathing teeth in sugar. He also advises diluting juices by adding water.

And because the acid in fruit can cause a temporary softening of the enamel, Lituchy says you should wait 45 minutes after consuming your smoothie to brush your teeth. Otherwise, you risk damaging the enamel while it's in a vulnerable state.

This rule holds true when you consume other things that are high in acidity (think lemons and limes) or that are high in sugar, like soda.

You wouldn't chew on a rock, right? So, why chew on something that's almost as hard as one? Breaking down a cube of ice requires a lot of pressure, which can wear down enamel and even cause it to chip. Not so cool, right?