WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
By Dr. Mercola
Halitosis, or bad breath, is bothersome and embarrassing. It affects nearly 50 percent of the general population1 and may originate either from your mouth or a non-oral source. Mouthwash has become the treatment option many turn to in order to relieve their symptoms.
Interestingly, early historical documents show the Romans would import bottled Portuguese urine to kill oral bacteria.2 The practice was so common that Nero placed a tax on the import. Urine remained a primary ingredient in mouthwash until the 18th century. In the 19th century alcohol replaced urine to kill germs.
Listerine first hit the market in the 1880s when it was used to clean feet and floors, as a surgical antiseptic and as a treatment for gonorrhea.3 The product was also marketed to dentists to kill oral bacteria. But it wasn't until the 1920s that the owner of the company began marketing the product for halitosis, framing it as a health condition that would keep you from being the best that you could be.
Although the campaign was highly successful, the company continued to market Listerine as a toothpaste, deodorant and a cure for dandruff. In other words, it was alcohol in a bottle said to cure a variety of common ailments. Today, in addition to alcohol, mouthwash products may also contain potassium sorbate, polymer 407, propylene glycol4 and caramel.5
A recent study, published in the journal Nitric Oxide, revealed the combination of these chemicals in your mouthwash may increase your risk of developing prediabetes or diabetes.6 This may be mediated by impairing the ability of oral bacteria to reduce nitrate to nitrite, thus impacting your systemic health.
Study Links Mouthwash Use to Disruption of Oral Bacteria
The authors believe this is the first study to look at mouthwash usage as it relates to the development of prediabetes or diabetes,7 and the relationship to blood pressure. Estimates suggest there are between 5008 and 7009 different species of bacteria that live on your teeth, tongue and oral mucosa, and these may double in number five times every 24 hours.10
The bacteria that live in your mouth are a mix of beneficial bacteria that assist your body, and pathogenic ones, responsible for poor health and bad breath. Mouthwash is designed to kill all the bacteria living in your mouth, which is not a good thing. According to information published by parent organization Johnson & Johnson about Listerine, you should swish for 30 seconds twice a day to kill up to 99 percent of all bacteria living in your mouth.11
Researchers used data from 945 participants who participated in the San Juan Overweight Adults Longitudinal Study (SOALS) who were free from diabetes and cardiovascular disease and had a complete follow up with the researchers.12 The participants either didn't use mouthwash or used it once or twice daily. Those who used the product twice daily, or more, had a nearly 50 percent greater chance of developing prediabetes or diabetes over those who used it much less or not at all.13
The researchers controlled for a variety of factors, including but not limited to medications, income, education, breathing disorders and diet. They concluded that frequent, regular use of mouthwash as recommended by manufacturers, resulted in an association with an increased risk of developing prediabetes or diabetes in this population. The American Dental Association states mouthwash may be helpful, but cautions:14
"Using a mouthwash does not take the place of optimal brushing and flossing. Mouthwashes may offer additional benefit in terms of reducing the risk of bad breath, cavities or gum disease; or for relief of dry mouth or pain from oral sores."
While a swig of mouthwash twice a day may seem innocuous and may be a part of your daily routine, this study demonstrates the indiscriminate eradication of oral bacteria may have long-term health consequences. However, given that 200 million in the U.S. routinely use mouthwash and nearly 100 million have diabetes or prediabetes,15 analyzing the effects of this habit could offer an additional strategy in an arsenal of lifestyle choices that may help prevent this devastating condition.
Oral Bacteria Play Vital Role in Your Overall Health
Your oral microbiome is vital to your overall health as it has been linked to chronic low-grade inflammation in your body, which in turn is associated with a number of chronic illnesses. Gum disease increases your risk for a heart attack by 50 percent,16 and advanced periodontal disease may further increase your risk of a fatal heart attack.
Allowing overgrowth of bad bacteria in your mouth causes tooth decay and gum disease, which in turn increases the number of bad bacteria that enter your circulatory system, triggering a release of C-reactive protein from your liver. This increases the level of chronic inflammation in your body that, over time, encourages the development of chronic disease. Thus, both killing all bacteria and allowing an overgrowth have negative effects on your health.
This is why balancing your oral microbiome is so important. While your oral microbiome is connected to your gut, it is quite unique. Your oral bacteria help protect your gut from foreign bacterial invaders and help begin the process of digestion. But, while it may be possible to effectively seed your gut microbiome, probiotics do not work in your mouth.
In a study from Uppsala University, researchers found nitrate-rich vegetables had a positive effect on reducing gastric ulcers.17 The nitrates are converted to nitrites in the mouth by oral bacteria and then into biologically active nitric oxide in the stomach that protects the mucosa.
Oral Bacteria Linked to Cardiovascular Health and Diabetes
The featured study demonstrates an association between killing all bacteria in your mouth and the development of diabetes and cardiovascular disease. The exact modality has not been identified, but like all systems in your body, the answer is likely more complex than one factor.
In a study published in the Journal of Periodontal Research,18 scientists discovered that multiple types of Actinobacteria are associated with the risk of obesity and Type 2 diabetes. They found people who suffered from Type 2 diabetes had less Actinobacteria in their oral microbiome than those who did not. In the featured study, lead author Dr. Kaumudi Joshipura explains her theory of how the use of mouthwash may be related to an increased risk of diabetes, saying:19
"Many bacteria in the mouth are able to metabolize nitrate into nitrite, which is then swallowed into the gastrointestinal tract, and then converted to nitric oxide. Most of these antibacterial ingredients in mouthwash is not selective. In other words, they do not target specific oral bacteria — instead, these ingredients can act on a broad range of bacteria."
The reduction in the amount of nitric oxide that is metabolized in your body is significant, as it is an important signaling molecule that helps regulate energy, metabolism and insulin levels, all of which are important in the development of pre-diabetes and Type 2 diabetes. In a study led by researchers from the University of London, the result of using mouthwash for just seven days reduced oral nitrite production by 90 percent and blood nitrite levels by 25 percent.20
In this study, the researchers found the effect of mouthwash on nitric oxide production resulted in a spike in blood pressure after one day that continued during the seven days the participants used mouthwash.21 These results suggest the endogenous process plays a significant role in determining plasma nitrite levels and control of your blood pressure. Nathan Bryan, Ph.D., one of the leading experts in the role of nitric oxide who was not involved in the featured study, explains:22
"Recent discoveries reveal that oral bacteria provide the human body with continuous sources of nitric oxide. Nitric oxide is one of the most important molecules produced in the human body. It controls and regulates blood pressure and is a major factor in preventing cardiovascular disease. Loss of nitric oxide is the earliest event in the onset and progression of cardiovascular disease (CVD), the leading killer of men and women worldwide.
Poor oral hygiene, the use of antiseptic mouthwash or antibiotics can kill these commensal bacteria and disrupt nitric oxide production putting patients at risk for CVD. For example, there is strong data that demonstrates that antiseptic mouthwashes may eliminate 'bad breath,' but, at the same time, they raise a significant risk of killing 'good', i.e., beneficial, oral bacteria that in turn, raises blood pressure. The rise, as much as 26 mm Hg, causes essential hypertension in healthy individuals."
Industry Association Not Convinced by This or Other Studies
Not surprisingly, industry associations are skeptical of the results of this study.23 Dr. William Cefalu, chief scientific, medical and mission officer for the American Diabetes Association, called the study interesting but is not convinced by the results, even though the study is supported by a decade of others before it, demonstrating destruction of oral microbiome has a negative effect on your health.
While the results of this study show the negative effects mouthwash has on your oral microbiome, the damage by alcohol and other antibacterial agents is only one of many dangers. Most mouthwashes contain fluoride, which has proven to be dangerous and has little if any benefit to your teeth. It is linked to reduced intelligence, osteoarthritis and insulin resistance.24
Cetylpyridinium chloride is another common ingredient found in mouthwash25 that is reportedly added to reduce plaque and tartar, but whose listed side effects include teeth staining, altered tasted perception and an increase in calculus production.26 Triclosan27 is added as an antibacterial. It has several dangers, including disruption of hormone regulation. A small study from Stanford University found while triclosan kills bacteria in your mouth, it may also slowly breed superbugs in your intestinal tract.28
Natural Alternative Is Safe, Healthy and Has Greater Benefits
One excellent alternative to manufactured toothpastes and mouthwashes is oil pulling. I've been consistently pulling with coconut oil since 2011, as it is a beneficial mechanical method of removing small bits of food and killing the bacteria that cause tooth decay and bad breath.
Oil pulling is an ancient Ayurvedic practice that strengthens teeth and gums and helps prevent tooth decay, bad breath and bleeding gums.29 The process is simple and easily done once a day. Measure out about 1 tablespoon of coconut oil. This may be too much or not enough, but it is a good place to start. The oil is in solid form below 76 degrees Fahrenheit (24.4 degrees Celsius) but liquefies quickly once in your mouth.
Move the oil around in your mouth to encourage quick liquefaction and then swish it using your tongue and cheeks to pull it through your teeth. Try to keep your jaw muscles relaxed to avoid muscle fatigue, much like mouthwash. However, you don't want to gargle it or swallow the oil you're pulling. When first starting, you may feel the urge to swallow, but it's important to spit it out and start again if you do to prevent this from happening.
While swishing, both saliva and bacteria are incorporated into the oil, which is why you don't want to swallow it. After about 20 minutes the oil begins to thicken and become milky white. It is important to spit it into your garbage or outside away from your plants as the oil could coat your plumbing, causing a blockage. Over time this practice becomes as natural as brushing your teeth.
By increasing the pH in your oral cavity after pulling you may reduce growth of harmful bacteria even further. Mix 1 teaspoon of baking soda in 6 ounces of water and gargle. This alkalizes your mouth, discouraging growth of bacteria that thrive in an acidic environment.
In addition to eliminating mouthwash and using coconut oil to clean your mouth, consider adding this simple exercise I demonstrate in this video. The Nitric Oxide Dump, so named by Dr. Zach Bush who developed it, has significant benefits to your health and wellness that go beyond just reducing your blood pressure.
The routine takes between three and four minutes and is typically done two to three times a day. You want to space the mini workouts at least two hours apart to allow nitric oxide regeneration. This simple exercise will increase your nitric oxide blood level, which in turn will help reduce your blood pressure, stimulate your immune function and decrease blood viscosity to reduce your risk of blood clots.