Coffee Contains Natural Compounds That Reduce Bad Breath

If you’ve ever worried your morning coffee might be worsening your breath—or avoided it entirely because you think it causes bad breath—you’re not alone. But what if coffee could actually help fight the very problem it’s blamed for?

Yes—new research shows certain compounds in coffee can inhibit the bacteria responsible for bad breath, potentially reducing the production of foul-smelling gases by as much as 90% in lab conditions.

Why Do We Associate Coffee With Bad Breath?

It’s a common belief that coffee leads to bad breath, especially when mixed with milk. The assumption is that coffee dries out the mouth and promotes bacterial fermentation, leading to odorous compounds. But according to Professor Mel Rosenberg, an expert in halitosis at Tel Aviv University, that’s only part of the story—and not the whole truth about coffee’s effect on breath odor.

The Surprising Lab Results

Rosenberg and his team conducted experiments using three types of coffee: two locally produced Israeli coffees and one Nestlé instant coffee. They introduced each type to samples of saliva in glass test tubes, expecting to confirm that coffee encourages the release of volatile sulfur compounds—the main culprits behind bad breath. To their surprise, the opposite happened. In multiple trials, coffee significantly reduced the production of these smelly gases, with reductions as high as 90% in some cases.

What Really Causes Bad Breath?

Bad breath often originates from volatile sulfur compounds (VSCs) produced by bacteria in the tongue, gums, and teeth. These microbes break down proteins in the mouth, releasing foul gases. Certain foods like garlic and onions worsen the issue because their components enter the bloodstream, are exhaled through the lungs, and linger until fully eliminated. Most commercial breath fresheners such as mouthwash and gum only temporarily mask these odors; they don’t eliminate the root microbial cause.

Coffee’s Hidden Benefit: Blocking Odor-Producing Bacteria

Rosenberg’s findings indicate that coffee contains unknown compounds capable of suppressing the bacteria that generate VSCs. Unlike mint, which merely covers the smell, these coffee-derived substances may target the microbial activity itself. The goal now is to isolate the specific active agents—not just crude coffee extracts—that prevent the formation of dental plaque and stop bad breath at the source. These compounds could eventually replace traditional masking agents in products like mouthwash, chewing gum, and breath sprays.

Frequently Asked Questions

Does coffee actually cause bad breath?

While many people believe coffee worsens bad breath—especially when consumed with milk—it’s more complicated. Coffee can dry out your mouth, which may allow bacteria to thrive, but recent research shows that coffee also contains compounds that can suppress the bacteria responsible for producing foul-smelling volatile sulfur compounds.

What did the Israeli study find about coffee and bad breath?

Researchers at Tel Aviv University tested Israeli-made and Nestlé instant coffee against saliva samples. Contrary to expectations, coffee reduced the production of bad-smelling gases by up to 90% in some experiments, suggesting it can inhibit the bacteria that cause halitosis.

How does coffee reduce volatile sulfur compounds?

The exact mechanism isn’t yet clear, but the study indicates that certain compounds in coffee block the activity of oral bacteria that produce volatile sulfur compounds. This suppression happens at the microbial level, not just by masking the odor.

Could coffee be used in mouthwash or gum?

Yes. Researchers aim to isolate the active compounds in coffee that reduce bad breath and use them as the basis for new mouthwash, breath spray, and chewing gum formulations—replacing current ingredients that only temporarily mask odors.

Why did the experiment use saliva and not real mouths?

Using saliva in test tubes allowed researchers to simulate oral conditions and measure the direct impact of coffee on bacteria that produce volatile sulfur compounds. It’s a controlled way to assess the anti-bacterial properties of coffee without other variables.

Recommended FrontStreet Coffee Beans for Fresh Breath

Try FrontStreet Coffee’s Ethiopia Humbera for a bright, citrusy cup with floral and stone fruit notes—its acidity helps cleanse the palate. For a smoother option, the Yirgacheffe offers jasmine and lemon zest with a clean finish. Both single origins highlight coffee’s natural brightness, which can complement oral freshness. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.