First off, food is a major culprit of bad breath. As we all know, food can get trapped in our teeth, creating a fertile environment for bacteria growth.

Next, food odors, especially garlic, onions, spices and alcohol can actually be absorbed into the blood and then be released through your lungs as you breathe. Also, diets rich in meat have a greater tendency to produce bad breath than vegetarian diets since they produce more fat and fatty acids which are released through your lungs.

But chances are, if you and your friend share a big, juicy steak smothered in onions, neither of you will be able to detect each other's bad breath since you quickly get used to that odor. The same rule applies to smokers: Smoky breath isn't usually noticed by those who smoke because of their tolerance to those specific odors. Remember, though, that there are a lot of people who may have had something different for lunch or don't smoke. These folks may smell you coming.
 
 

Does sugar or sugary drinks cause bad breath?
 

No and no. Surprisingly enough, it's been shown that simple sugars (e.g. glucose, sucrose) actually create a low pH environment which inhibits growth of odor causing bacteria. And since carbonated and citrus drinks naturally have a low pH, odor causing bacteria don't have a chance to grow.

However, it is possible that sugary drinks may cause dryness of the mouth which can lead to bad breath. For more information, see below.
 
 

Do some medications cause bad breath?

Absolutely. Some medications can cause bad breath by reducing your mouth's salivary flow. And when washing or flushing of the mouth decreases, bacterial growth increases. The most common products which can cause dry mouth are cold and/or allergy medications containing antihistamines. Several classes of prescription drugs including amphetamines, tranquilizers, nausea medications and diuretics can also cause dry mouth. Ask your doctor for specific information on a drug you may be taking.
 
 
 

Can I get bad breath from exercise?

Sometimes. When you exercise, you may do heavy breathing through your mouth. This leads to dry mouth, which in turn, can lead to bad breath in much the same way that some medications cause bad breath.
 
 

What should I do to prevent bad breath?

Routine brushing, flossing and rinsing with mouthwash can all help ward off bad breath. Remember, good oral hygiene is bad breath's worse nightmare. A mouthwash like Scope® can freshen your breath a few different ways: by cleansing the mouth in places a toothbrush can't reach, killing the germs that cause bad breath.