According to Erin Fraundorf, DMD, MSD, an orthodontist and founder of BOCA Orthodontic + Whitening Studio, what you eat plays a huge role in the way your breath smells, especially on a microscopic level. In fact, certain foods that cause bad breath can disrupt the delicate balance of the oral microbiome. So, what gives? Ahead, two dental health experts share the top seven foods that can promote bad breath, plus seven foods that can make it smell better.

How can food cause bad breath?

Although there are many causes for bad breath, food is one of the main causes that can fuel the growth of bacteria. “When we eat, food debris sticks to various surfaces in our mouths—such as your teeth, tongue, and gum tissues—providing a food source for bacteria,” Dr. Fraundorf explains. As bacteria consume this food this can produce odor-causing acid, she says.

Michael Wei, DDS, a New York City-based cosmetic dentist, agrees that foods, particularly sugar-laden ones, can also create the ideal environment for bacteria to flourish. “Sugary foods can contribute to bad breath by creating an environment in the mouth where bacteria thrive and produce odorous byproducts,” Dr. Wei says.

That’s not all; Dr. Fraundorf also points out certain types of odorous foods can also cause bad breath by entering the bloodstream. “[The smell] is released with the breath, or during exhalation,” she says. Meanwhile, Dr. Wei notes that certain foods—like garlic, onions, and certain spices—contain sulfur compounds that can linger in the mouth and also lead to bad breath. Ahead, we’re sharing seven foods (and drinks!) that can lead to bad breath.

7 foods and drinks that can cause bad breath

1. Sugary foods

Sugary and carbohydrate-rich foods can cause bad breath. “A diet high in sugar and carbohydrates can lead to plaque buildup and bad breath due to how much oral bacteria like to feed on the sugars,” Dr. Fraundorf says.

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2. Coffee

According to Dr. Fraundorf, coffee consumption can impact saliva production which can induce a bout of bad breath. “The caffeine in coffee leads to a decline in saliva production which subsequently increases odor-causing bacteria,” she says.

3. Garlic and onions

Garlic and onions are notorious for contributing to bad breath. But why? Dr. Fraundorf says they’re potent enough to get into your bloodstream. “These foods have a smelly sulfur compound that lingers in your mouth. Additionally, they get absorbed in the bloodstream and are expelled with each breath when you exhale,” she says.

4. Alcohol

Similar to coffee and caffeinated beverages, Dr. Wei says alcoholic drinks can have a drying effect on the mouth, causing bacteria to multiply and result in bad breath.

5. Dairy products

According to Dr. Wei, some dairy products, like milk and cheese, can promote the production of compounds that contribute to bad breath when broken down by bacteria in the mouth. For example, amino acids in dairy interacts with bacteria in your mouth, which can produce odorous smells and sulfuric release.

6. Spicy foods

Spicy foods can heavily impact digestion, which can lead to bad breath. “Spicy foods can increase the production of stomach acids, which can reflux into the mouth and cause bad breath,” Dr. Wei says. This is typically due to capsaicin, a compound in spicy food, that can stimulate gastric activity.

7. Fish

Fish contain proteins that can break down into foul-smelling compounds if not properly digested, leading to bad breath, says Dr. Wei. According to the American Society of Nutrition, this is due to trimethylamine (TMA), a chemical that can trigger this smell.

7 foods and drinks that can promote good breath

Aside from establishing a comprehensive oral hygiene routine, consuming these foods and beverages might help keep bad breath away.

1. Crunchy fruits and vegetables

According to Dr. Wei, crunchy fruits and vegetables, like apples, carrots, and celery, can help stimulate saliva production that’s key for keeping bad breath at bay. “These foods help stimulate saliva production, which is essential for neutralizing acids and washing away food particles and bacteria in the mouth. Saliva also contains minerals that help protect tooth enamel,” he says.

Dr. Fraundorf also recommends strawberries, watermelon, and apples, as they contain malic acid. “It helps whiten your smile by removing surface stains and increasing saliva,” she says. Other foods, like celery and leafy greens, can also help promote oral health thanks to their fibrous texture. “It’s like a natural toothbrush that exfoliates plaque off your teeth,” she adds.

Dark, leafy greens also contain calcium that helps counteract the effects of harmful acids and an abundance of folic acid that are essential to gum tissue cell growth, explains Dr. Fraundorf. “Vitamin C-rich foods, like berries, red bell pepper, melons, and broccoli have also been found to create an inhospitable environment for mouth bacteria,” she says.

2. Ginger

Dr. Fraundorf recommends consuming ginger to help neutralize some of the odor-causing bacteria in your mouth. In fact, ginger contains 6-gingerol, a compound that stimulates enzymes that naturally break down foul-smelling bacteria.

3. Probiotic-rich foods

Both doctors recommend consuming probiotic-rich foods that can help support a healthy oral microbiome. “Probiotic-rich foods like yogurt can help maintain a healthy balance of good bacteria in the mouth, which is important for controlling odor-causing bacteria,” Dr. Wei says.

4. Herbs

According to Dr. Fraundorf, certain kinds of herbs can help eliminate bad breath. “Parsley contains chlorophyll, which has been found to have a deodorizing effect as it can kill bad oral bacteria. Some other herbs that have been found to improve breath, include spearmint, coriander, fennel seeds, clove, and anise,” she says.

5. Sugarless gum

Dr. Wei and Dr. Fraundorf both recommend consuming sugar-free gum to promote good breath. Studies show that cavities are significantly lower in patients that chew sugar-free gum for twenty minutes after meals. “Chewing sugar-free gum increases salivary flow by stimulating mechanical and taste receptors in the mouth. Saliva helps wash away food particles as well as dilute and neutralize acids produced by plaque bacteria on teeth, leading to a reduction in cavities, stains, and bad breath,” Dr. Fraundorf explains.

6. Green tea

Green tea contains polyphenols, which are compounds with antioxidant properties that can help reduce the growth of bacteria in the mouth, says Dr. Wei. “It also has anti-inflammatory properties that can help promote gum health,” he shares.

7. Water

Plain ol’ H2O can also help promote good breath. “Staying hydrated by drinking plenty of water helps wash away food particles and bacteria in the mouth. It also helps stimulate saliva production, which is crucial for maintaining good oral health,” Dr. Wei says. Meanwhile, Dr. Fraundorf notes that “plain, flat water is odor-free, neutral in its pH, and naturally acts to cleanse the oral environment by helping flush from the mouth the bits of food bacteria feed on.”

What is the most common cause of bad breath?

While certain foods can contribute to bad breath, poor oral health and hygiene are its primary causes. “If you don’t properly clean your teeth and mouth regularly, a sticky buildup of bacteria—also known as plaque—forms,” Dr. Fraundorf says. She also points out that your tongue and tonsils can also trap food particles and bacteria due to their bumpy surfaces, hugely contributing to bad breath.

Having a dry mouth (aka xerostomia) can also cause bad breath. “Saliva provides the mouth with a self-cleansing ability by washing away food particles. When there is decreased production of saliva, your mouth becomes more dry, and thus, the environment for odor-causing bacteria thrives,” Dr. Fraundorf says. This typically occurs at night, due to other chronic health conditions, or depending on what you eat. It’s a logical explanation for why so many of us experience “morning breath.”

Additional causes of bad breath

There are additional factors that can contribute to bad breath aside from what you eat and how you care for your mouth. In fact, Dr. Wei says bad breath (aka halitosis), can be indicative of various underlying conditions. For example, he explains periodontal disease can cause persistent bad breath due to the presence of bacteria in the gums and pockets around the teeth.

Respiratory infections, such as sinusitis, bronchitis, or pneumonia, can also contribute to bad breath. “When you get a cold and your nose starts running, you experience excess postnasal mucus drip—mucus dripping down the back of your throat. This drip is optimal for bacterial multiplication, leading to bad breath. While with sinus infections, the circulation of mucus stops, leading to a large buildup of bacteria,” Dr. Fraundorf says.

Dr. Fraundorf says digestive issues such as poor digestion, acid reflux, constipation, and bowel disorders can also contribute to bad breath, along with smoking, certain prescription medications, diseases related to the liver and kidneys, blood disorders, lung cancer, stomach cancer, or other potentially serious metabolic disorders.

Bottom line

Although bad breath is generally no cause for true concern, it’s important to monitor symptoms if they continue. “If bad breath persists despite good oral hygiene practices, it’s important to see a dentist for further evaluation. Bad breath can be a symptom of underlying dental issues such as gum disease, cavities, or oral infections. A dental professional can help identify the underlying cause of bad breath and recommend appropriate treatment,” Dr. Wei says.