We often suspect that there is a connection between food and bad breath: the mouth might taste a little strange after a meal containing spicy food or food with strong flavors, and certain foods such as cucumbers and raw onions tend to be followed by burping and breath which tastes, to us, rather unpleasant. These problems are transient however, and tend to pass within a few hours, the question is, does food really cause bad breath? It can do so in a number of ways that researchers in the field are just beginning to understand. The important ones are those that foster the proliferation of anaerobes – bacteria that live in the mouth and produce sulfur compounds with a foul odor.
Some of the known foods that cause bad breath are drying agents – they cause a decrease in the amount of saliva in the mouth. Saliva flushes out the oral cavity, kills off harmful organisms, and keeps the oral tissues healthy. When there is too little of it, food particles and other proteins remain in the mouth and begin to break down. They feed anaerobic bacteria, which are not being washed away. The delicate cells lining the mouth can start to break down. All of this promotes the proliferation of anaerobes and their bad smelling byproducts. Alcohol and tobacco are both notorious drying agents; however, anything that dries out your mouth can forge the link between food and bad breath.
Foods high in protein or sugar, and those with an acid pH have also been identified as foods that cause bad breath. In each case, the foods promote the growth of anaerobic bacteria. Protein breaks down in the mouth producing amino acids, which bacteria eagerly consume and use as cell building blocks, much as our own bodies use amino acids to build and repair tissue. Sugary foods provide carbohydrate energy for cell metabolism, and acid foods create a low pH that many bacteria love. In the end, food and bad breath are related to each other because the same nutrients that feed us also feed the bacteria that cause bad breath. If we keep our mouths clean and healthy, brushing and rinsing after eating, there will be less for bacteria to eat.
Spices and strong flavored foods cause an unpleasant odor on the breath, and sometimes it is related to sulfur compounds; however, these odors do not originate with oral bacteria. They are directly related to the odor or the digestion of the food itself and thus, disappear after a few hours – a day at most. Typical foods that cause bad breath in this manner are spices such as curry, cumin, and paprika, onion, garlic, strong cheeses, fish, smoked products, and fermented foods. Those who love these foods shouldn’t have to give them up: use breath mints (avoid sugar) or other breath fresheners to mitigate the problem. Remember, too, that food and bad breath can be related in an opposite way: certain herbs and spices, such as mint, parsley, cilantro, cloves, and cardamom are great natural foods for freshening the breath.