What leads to halitosis?

What could be more awkward than chatting with someone who stands too close? Talking to a close talker with unmistakably bad breath. Let's face it, even the best of us suffer from bad breath occasionally. Imagine enjoying a plate of pasta primavera and unknowingly consuming a whole clove of garlic. Or perhaps indulging in a cheesesteak sandwich loaded with onions. Even after brushing your teeth and rinsing with mouthwash, the lingering smell of your meal can cling to your breath like an earworm you can't shake. No matter what you try, sometimes that stubborn odor just won't go away.

Bad breath is often associated with garlic and onions. These common kitchen ingredients can cause temporary halitosis due to their chemical composition. Garlic, for example, contains allicin, a sulfur compound responsible for its strong aroma [source: Herbert]. This compound can lead to breath that makes others recoil.

Persistent cases of foul breath, known as halitosis, are more challenging to address than simply avoiding strong-flavored foods. Halitosis impacts roughly one in four adults, not to mention the many individuals with healthy mouths who take extra steps to ensure their breath remains pleasant [source: Haraszthy et al]. Additionally, some people suffer from halitophobia, an intense fear of bad breath, which can be so severe that dentists may recommend psychological support.

Consequently, the oral hygiene market is thriving. Shelves in grocery stores and pharmacies are filled with a wide variety of products designed to combat oral odors, including gums, sprays, toothpastes, and more. Experts predict that by 2010, sales in the United States alone will reach nearly $5 billion [source: Alexander]. This concern isn't unique to Americans; other cultures have their own methods for freshening breath, such as chewing cloves in Iraq, cinnamon in Brazil, and guava peels in Singapore [source: Fisher].

But what exactly happens inside our mouths to cause halitosis? Open wide, say "ahhh," and let's uncover the root of those unpleasant smells.

Bacteria in the Mouth: How Halitosis Happens

Similar to the cause of a stubborn cough or a runny nose, chronic halitosis, or bad breath originating from the mouth, stems from bacteria. On average, a person harbors around 800 different types of bacteria in their mouth [source: Haraszthy et al]. If you were to zoom in on a single cell from your tongue, you might find up to 100 types of bacteria attached to it [source: Yaegaki and Coil].

The mouth functions like a bacteria production facility, equipped with perfect conditions for microorganisms to thrive and multiply. Think of your mouth's environment as similar to a sauna. Just as the heat and humidity in a sauna cause our bodies to sweat profusely, the warm, moist conditions in our mouths encourage bacterial growth. However, it's not just the bacteria that cause bad breath; it's the combination of the food we consume and the bacteria in our mouths that triggers the reaction, leaving you reaching for a breath mint.

Some bacteria contribute to bad breath by breaking down leftover proteins from food particles, dead cells, and mucus into amino acids. To extract energy from these amino acids, the bacteria further break them down, releasing volatile sulfuric gases. These gases produce the familiar rotten egg smell often added to natural gas to help detect leaks. These bacteria are most abundant in hard-to-reach areas of the mouth, such as the spaces between teeth and the back of the tongue. 

Dry mouth also exacerbates halitosis. Saliva acts as a natural mouthwash, removing excess food particles and washing away bacteria. During sleep, saliva production decreases, which is why we wake up with morning breath. Individuals with chronic dry mouth, or xerostomia, experience even stronger morning breath. Certain medications, such as antidepressants, painkillers, and antihistamines, can also cause dry mouth as a side effect, further contributing to bad breath [source: Haraszthy et al].

While oral bacteria are responsible for 85 percent of halitosis cases, bad breath can also signal issues in other parts of the body [source: Merck]. For instance, sinus infections or severe colds can worsen breath due to increased mucus production, which drips down the throat and onto the tongue. Conditions like gastrointestinal disorders, kidney issues, and lung infections can also affect breath odor. Additionally, skipping meals can lead to unpleasant breath: when the body lacks sugar for energy, it begins burning fat through a process called ketoacidosis, resulting in breath that smells fruity [source: Mayo Clinic].

Now that we understand the causes of halitosis, how can we effectively address it?

How to Cure Halitosis

Most breath mints offer only temporary relief, akin to a small snack for a hungry stomach. Their initial burst of minty freshness quickly masks any unpleasant tastes, but the effect is short-lived. Soon, the refreshing sensation fades, and the unpleasant odor returns, leaving us back where we started.

To effectively combat bad breath, your first and most cost-effective step is to stop feeding the bacteria. The main culprits behind bad breath are leftover food particles, which is why thorough brushing and regular flossing are essential. When cleaning your mouth, don’t forget to focus on the back of your tongue. Use a toothbrush or tongue scraper to reach as far back as possible, targeting the primary hub of odor-causing bacteria. Neglecting this can lead to periodontal disease and gingivitis, both of which worsen bad breath. Gaps between unhealthy gums and teeth create ideal environments for bacteria to thrive.

Mouthwash is one of the most popular products people buy to fight halitosis. According to the British Medical Journal, solutions containing chlorohexidrine gluconate are effective at eliminating troublesome bacteria [source: Scully et al]. Using it before bed helps ensure fresher morning breath, as dry mouth during sleep encourages bacterial growth [source: Fisher].

Unsurprisingly, your daily diet plays a significant role in how your breath smells. Drinking water throughout the day benefits not only your overall health but also your breath by flushing away bacteria and food particles that cause halitosis. Foods like parsley, fennel seeds, and carrots can also help keep your breath fresh.

If better oral hygiene doesn’t resolve your halitosis and you suspect a chronic issue, it’s time to visit your dentist. They can recommend stronger measures to address the problem. As previously mentioned, bad breath might stem from issues outside the mouth, in which case a doctor can help identify the root cause.

If you’re worried about how your breath smells, you’re not alone. Approximately 25 percent of people who seek help from halitosis specialists don’t actually have chronic halitosis [source: Fisher]. Many people overestimate how bad their breath smells. While garlic and onion-heavy meals can worsen breath odor, proper oral care can keep your mouth feeling fresh and clean.