Bad breath, also known as halitosis, is a combination of poor oral hygiene and diet and may be a sign of other health problems. The three causal factors which create bad breath are: anaerobic oral bacteria, smelly sulphur compounds and biological film. The different compounds that are responsible for these stinky smells are found in everyone’s mouth and if their concentration is high enough bad breath can occur.

The bacteria in our mouth consume the foods we eat and excrete waste byproducts. Some types of oral bacteria produce smelly sulphur compounds (volatile sulphur compounds) as their waste byproduct and these molecules are usually the source of a person’s breath problems. The three main volatile sulphur compounds are: hydrogen sulphide (rotten egg smell), methyl mercaptan (feedlots and barnyard smell) and dimethyl sulphide (canned creamed corn or asparagus smell). These VSC’s are the byproduct of anaerobic bacteria. Anaerobic describes the fact that these bacteria prefer an environment without oxygen.

This is where dental biofilms come into play. The accumulation of biological films, (whitish coating on teeth, tongue and below the gum line) can promote the growth of odour-causing bacteria. As the biofilm builds up, a transition takes place where at it’s base it becomes more oxygen-depleted and increases the beneficial environment for the anaerobic bacteria to grow. So one way of controlling the number of these odour-causing bacteria in your mouth is to minimize the amount of biofilm (dental plaque) by tooth brushing, flossing and tongue cleaning.

The role that food sources play in affecting our breath odour begins with the protein we consume, or more specifically, the building block molecules of the sulphur-containing amino acids that proteins are made from. These are primarily methionine and cysteine. These two molecules are still essential to our good health but limiting our intake of proteins that are excessively rich in them will help control the growth of the bad anaerobic bacteria that flourish on them in our mouths. Foods that are rich in both methionine and cysteine include pork, beef, tuna, chicken and turkey.

Foods high in saturated fats are also a problem as they produce inflammation which has been proven as a key underlying causal factor in periodontal disease. The same anaerobic bacteria responsible for bad breath are also key in periodontal disease. Therefore, moderating or eliminating intake of meat, eggs and dairy which are high in saturated fats can promote periodontal health as well as improve your breath.

A whole food plant based diet is beneficial for protection against bad breath and periodontal health because it has no saturated fat, cholesterol or animal protein. It also contains higher levels of complex carbohydrates, dietary fiber, vitamins, minerals, antioxidants and phytochemicals which are protective and exert many beneficial and clinically relevant effects on general health as well as oral health. Foods high in dietary fiber such as whole grains, nuts, beans, fruits and vegetables are beneficial due to the increased saliva production generated as these foods need to be chewed more intensively, which has a self-cleaning effect on the back of the tongue. Foods that require less chewing have been proven to be less effective in improving bad breath. Dietary nitrites in the form of greens and beets have been proven beneficial for maintaining good blood flow and reducing inflammation in the mouth improving periodontal disease.

Green tea is also favourable to use in the fight against bad breath as the polyphenols contained in green tea have been shown to improve oral malodor due to it’s antimicrobial and deodorizing effects.