Tongue scraping can boost the ability of the good bacteria in our mouth to take advantage of the nitrates in greens to improve our cardiovascular health.
How Tongue Scraping Can Affect Heart Health
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
The human mouth is an important habitat for microbes––harboring up to ten billion bacteria, and no wonder. It’s all warm and moist, providing a suitable environment for bacterial growth, some of which are actually beneficial. For example, it is widely recognized that dietary nitrate affords cardiovascular protection by turning into nitric oxide. And guess what contributes to the generation of nitric oxide? Our oral microbiome.
First, we eat nitrate-rich vegetables, like dark green leafies and beets. The nitrate is then absorbed into our bloodstream, and our body then pulls it out of circulation to be concentrated in our salivary glands and secreted back into the oral cavity. Why? Because our body knows there are good bacteria on our tongue to tweak it, eventually resulting in the synthesis of the artery-protecting nitric oxide.
We’ve got more than a billion people with high blood pressure, most of which is uncontrolled. As such, it is critical to optimize daily behaviors to support blood pressure regulation. And incorporating nitrate-rich foods may be an optimal strategy as it supports opening of our arteries via the enterosalivary pathway—the gut-saliva pathway—thanks to the friendly flora in our mouth. Dietary nitrate can provide sustained blood pressure lowering, and that starts with eating our greens. Leafy green vegetables contribute 80 percent of nitrate intake. But it doesn’t matter how many greens we eat if we have “oral dysbiosis”––if we don’t have the right tongue bugs to take advantage of them.
How can you screw up your oral friendly flora? By using an antiseptic mouthwash. Yeah, it can kill the bad bugs that cause plaque, but it can indiscriminately kill the good bugs too. And that can have systemic consequences. For example, studies show an increase in blood pressure following the use of antibacterial mouth rinses, because they reduce the protective bacteria in your mouth necessary for the nitric oxide pathway––a pathway that’s vital to blood pressure regulation and overall cardiovascular health.
Just a single week of antibacterial mouthwash use can cause a significant increase in blood pressure. And it’s not just one study. All human studies done to date have revealed deleterious effects of antibacterial mouthwash. Okay, so what about tongue cleaning, brushing your tongue, or using a tongue scraper?
Regular tongue cleaning is recommended by the American Dental Association as a way to cut down on the bacteria on your tongue that cause bad breath. But if it wipes out those bacteria, might it wipe out the good ones too? It turns out tongue cleaning may give you the best of both worlds. Those who cleaned their tongue twice or more per day as part of their normal oral hygiene were more likely to have an increase in systolic blood pressure during use of the antibacterial mouthwash, suggesting they had more of the good bugs to kill. Here’s the graph. The mouthwash was worse for those with better tongue hygiene. So, regular tongue cleaning may result in a baseline tongue microbiome that has a greater ability to tweak nitrate, and, conversely, failure to clean the tongue daily may result in a microbiome composition that is unfavorable to nitrate conversion.
Now, but wait a second. Maybe tongue cleaning just disrupts the surface bacteria, making them easier for the mouthwash to pick off. To see if tongue cleaning was actually associated with a better oral microbiome, they did DNA analyses to elucidate the dynamics of the tongue microbiome, to compare differences between time points and tongue hygiene cohorts. And…it turns out tongue-cleaning does appear to have a significant impact on the composition of the tongue microbiome, specifically increasing the proportion of the good bacteria. So, based on this study, tongue cleaning assumes a new importance from the perspective of blood pressure regulation, as daily tongue cleaning appears to favor the increased abundance and metabolic activity of the nitrate metabolizing species like Neisseria, whereas failure to clean the tongue daily may result in a microbiome composition that is less favorable to nitric oxide production. Now, you still have to eat your vegetables—regular tongue cleaning together with adequate dietary intake of nitrate, since that has a two-fold benefit.
First, dietary nitrate improves artery function. Eat some nitrate rich vegetables, and within three hours, an improvement of artery function. And the nitrate can also act as a prebiotic for the oral microbiome. The most abundant best nitrate converter is Neisseria flavescens, and you can boost its abundance after feeding it with vegetables. After six weeks of a beet juice that’s had its nitrate removed, not much change, but after six weeks of regular beet juice and Neisseria jumps right up, making your mouth a nitric oxide-making machine.
And if you look at the association between nitrate-reducing oral bacteria and cardiometabolic outcomes, having more of these good bacteria in your mouth is linked to all sorts of cardiometabolic benefits, letting you take full advantage of the veggies you eat. What if all you ate was plants? A study on the impact of a vegan diet on the human salivary microbiome found a fully plant-based was associated significantly with more of the good Neisseria bugs that help you churn out nitric oxide. So, not only does eating plant-based boost the beneficial bacteria at the end of your digestive tract, but at the beginning too.
And eating nitrite-rich vegetables like greens doesn’t just boost the good bacteria, but beats down the bad guys––bacteria that cause cavities, bad breath, and gum disease. And indeed, if you feed people lettuce, or lettuce juice, so you can do a randomized, double-blinded, placebo-controlled trial with a lettuce juice control that has had the nitrate removed, you can significantly improve the health of your gums with greens. The researchers conclude: “Dietary nitrate consumption may be a useful adjunct in the control of chronic gingivitis.”
So, when reviews suggest there’s no reason to clean your tongue unless you have bad breath, and in the absence of a coating on your tongue there’s no reason to clean it, that was all before these new data, which suggest additional benefits. The only caveat would be those with heart valve problems, a pacemaker, or anything else that puts you at risk for endocarditis (an infection within the heart); you may want to stay away from tongue scraping, given this case report tentatively tying the two together. Just like you can get a heart infection after tongue piercing, tongue scraping may introduce a few bacteria into your bloodstream that could be hazardous for someone at risk.
Please consider volunteering to help out on the site.
- Tribble GD, Angelov N, Weltman R, et al. Frequency of tongue cleaning impacts the human tongue microbiome composition and enterosalivary circulation of nitrate. Front Cell Infect Microbiol. 2019;9:39.
- Ileri Keceli T, Gulmez D, Dolgun A, Tekcicek M. The relationship between tongue brushing and halitosis in children: a randomized controlled trial. Oral Dis. 2015;21(1):66-73.
- Senkus KE, Crowe-White KM. Influence of mouth rinse use on the enterosalivary pathway and blood pressure regulation: A systematic review. Crit Rev Food Sci Nutr. 2020;60(17):2874-86.
- Rocha BS, Laranjinha J. Nitrate from diet might fuel gut microbiota metabolism: Minding the gap between redox signaling and inter-kingdom communication. Free Radic Biol Med. 2020;149:37-43.
- Kapil V, Khambata RS, Robertson A, Caulfield MJ, Ahluwalia A. Dietary nitrate provides sustained blood pressure lowering in hypertensive patients: a randomized, phase 2, double-blind, placebo-controlled study. Hypertension. 2015;65(2):320-7.
- Bondonno CP, Liu AH, Croft KD, et al. Antibacterial mouthwash blunts oral nitrate reduction and increases blood pressure in treated hypertensive men and women. Am J Hypertens. 2015;28(5):572-5.
- Velmurugan S, Gan JM, Rathod KS, et al. Dietary nitrate improves vascular function in patients with hypercholesterolemia: a randomized, double-blind, placebo-controlled study. Am J Clin Nutr. 2016;103(1):25-38.
- Rosier BT, Buetas E, Moya-Gonzalvez EM, Artacho A, Mira A. Nitrate as a potential prebiotic for the oral microbiome. Sci Rep. 2020;10(1):12895.
- Hyde ER, Andrade F, Vaksman Z, et al. Metagenomic analysis of nitrate-reducing bacteria in the oral cavity: implications for nitric oxide homeostasis. PLoS One. 2014;9(3):e88645.
- Goh CE, Trinh P, Colombo PC, et al. Association between nitrate-reducing oral bacteria and cardiometabolic outcomes: results from origins. J Am Heart Assoc. 2019;8(23):e013324.
- Hansen TH, Kern T, Bak EG, et al. Impact of a vegan diet on the human salivary microbiota. Sci Rep. 2018;8(1):5847.
- Tomova A, Bukovsky I, Rembert E, et al. The effects of vegetarian and vegan diets on gut microbiota. Front Nutr. 2019;6:47.
- Jockel-Schneider Y, Goßner SK, Petersen N, et al. Stimulation of the nitrate-nitrite-NO-metabolism by repeated lettuce juice consumption decreases gingival inflammation in periodontal recall patients: a randomized, double-blinded, placebo-controlled clinical trial. J Clin Periodontol. 2016;43(7):603-8.
- Danser MM, Gómez SM, Van der Weijden GA. Tongue coating and tongue brushing: a literature review. Int J Dent Hyg. 2003;1(3):151-8.
- Seemann R, Conceicao MD, Filippi A, et al. Halitosis management by the general dental practitioner--results of an international consensus workshop. J Breath Res. 2014;8(1):017101.
- Redmond AM, Meiklejohn C, Kidd TJ, Horvath R, Coulter C. Endocarditis after use of tongue scraper. Emerg Infect Dis. 2007;13(9):1440-1.
- Aylıkcı BU, Colak H. Halitosis: From diagnosis to management. J Nat Sci Biol Med. 2013;4(1):14-23.
Motion graphics by Avo Media
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
The human mouth is an important habitat for microbes––harboring up to ten billion bacteria, and no wonder. It’s all warm and moist, providing a suitable environment for bacterial growth, some of which are actually beneficial. For example, it is widely recognized that dietary nitrate affords cardiovascular protection by turning into nitric oxide. And guess what contributes to the generation of nitric oxide? Our oral microbiome.
First, we eat nitrate-rich vegetables, like dark green leafies and beets. The nitrate is then absorbed into our bloodstream, and our body then pulls it out of circulation to be concentrated in our salivary glands and secreted back into the oral cavity. Why? Because our body knows there are good bacteria on our tongue to tweak it, eventually resulting in the synthesis of the artery-protecting nitric oxide.
We’ve got more than a billion people with high blood pressure, most of which is uncontrolled. As such, it is critical to optimize daily behaviors to support blood pressure regulation. And incorporating nitrate-rich foods may be an optimal strategy as it supports opening of our arteries via the enterosalivary pathway—the gut-saliva pathway—thanks to the friendly flora in our mouth. Dietary nitrate can provide sustained blood pressure lowering, and that starts with eating our greens. Leafy green vegetables contribute 80 percent of nitrate intake. But it doesn’t matter how many greens we eat if we have “oral dysbiosis”––if we don’t have the right tongue bugs to take advantage of them.
How can you screw up your oral friendly flora? By using an antiseptic mouthwash. Yeah, it can kill the bad bugs that cause plaque, but it can indiscriminately kill the good bugs too. And that can have systemic consequences. For example, studies show an increase in blood pressure following the use of antibacterial mouth rinses, because they reduce the protective bacteria in your mouth necessary for the nitric oxide pathway––a pathway that’s vital to blood pressure regulation and overall cardiovascular health.
Just a single week of antibacterial mouthwash use can cause a significant increase in blood pressure. And it’s not just one study. All human studies done to date have revealed deleterious effects of antibacterial mouthwash. Okay, so what about tongue cleaning, brushing your tongue, or using a tongue scraper?
Regular tongue cleaning is recommended by the American Dental Association as a way to cut down on the bacteria on your tongue that cause bad breath. But if it wipes out those bacteria, might it wipe out the good ones too? It turns out tongue cleaning may give you the best of both worlds. Those who cleaned their tongue twice or more per day as part of their normal oral hygiene were more likely to have an increase in systolic blood pressure during use of the antibacterial mouthwash, suggesting they had more of the good bugs to kill. Here’s the graph. The mouthwash was worse for those with better tongue hygiene. So, regular tongue cleaning may result in a baseline tongue microbiome that has a greater ability to tweak nitrate, and, conversely, failure to clean the tongue daily may result in a microbiome composition that is unfavorable to nitrate conversion.
Now, but wait a second. Maybe tongue cleaning just disrupts the surface bacteria, making them easier for the mouthwash to pick off. To see if tongue cleaning was actually associated with a better oral microbiome, they did DNA analyses to elucidate the dynamics of the tongue microbiome, to compare differences between time points and tongue hygiene cohorts. And…it turns out tongue-cleaning does appear to have a significant impact on the composition of the tongue microbiome, specifically increasing the proportion of the good bacteria. So, based on this study, tongue cleaning assumes a new importance from the perspective of blood pressure regulation, as daily tongue cleaning appears to favor the increased abundance and metabolic activity of the nitrate metabolizing species like Neisseria, whereas failure to clean the tongue daily may result in a microbiome composition that is less favorable to nitric oxide production. Now, you still have to eat your vegetables—regular tongue cleaning together with adequate dietary intake of nitrate, since that has a two-fold benefit.
First, dietary nitrate improves artery function. Eat some nitrate rich vegetables, and within three hours, an improvement of artery function. And the nitrate can also act as a prebiotic for the oral microbiome. The most abundant best nitrate converter is Neisseria flavescens, and you can boost its abundance after feeding it with vegetables. After six weeks of a beet juice that’s had its nitrate removed, not much change, but after six weeks of regular beet juice and Neisseria jumps right up, making your mouth a nitric oxide-making machine.
And if you look at the association between nitrate-reducing oral bacteria and cardiometabolic outcomes, having more of these good bacteria in your mouth is linked to all sorts of cardiometabolic benefits, letting you take full advantage of the veggies you eat. What if all you ate was plants? A study on the impact of a vegan diet on the human salivary microbiome found a fully plant-based was associated significantly with more of the good Neisseria bugs that help you churn out nitric oxide. So, not only does eating plant-based boost the beneficial bacteria at the end of your digestive tract, but at the beginning too.
And eating nitrite-rich vegetables like greens doesn’t just boost the good bacteria, but beats down the bad guys––bacteria that cause cavities, bad breath, and gum disease. And indeed, if you feed people lettuce, or lettuce juice, so you can do a randomized, double-blinded, placebo-controlled trial with a lettuce juice control that has had the nitrate removed, you can significantly improve the health of your gums with greens. The researchers conclude: “Dietary nitrate consumption may be a useful adjunct in the control of chronic gingivitis.”
So, when reviews suggest there’s no reason to clean your tongue unless you have bad breath, and in the absence of a coating on your tongue there’s no reason to clean it, that was all before these new data, which suggest additional benefits. The only caveat would be those with heart valve problems, a pacemaker, or anything else that puts you at risk for endocarditis (an infection within the heart); you may want to stay away from tongue scraping, given this case report tentatively tying the two together. Just like you can get a heart infection after tongue piercing, tongue scraping may introduce a few bacteria into your bloodstream that could be hazardous for someone at risk.
Please consider volunteering to help out on the site.
- Tribble GD, Angelov N, Weltman R, et al. Frequency of tongue cleaning impacts the human tongue microbiome composition and enterosalivary circulation of nitrate. Front Cell Infect Microbiol. 2019;9:39.
- Ileri Keceli T, Gulmez D, Dolgun A, Tekcicek M. The relationship between tongue brushing and halitosis in children: a randomized controlled trial. Oral Dis. 2015;21(1):66-73.
- Senkus KE, Crowe-White KM. Influence of mouth rinse use on the enterosalivary pathway and blood pressure regulation: A systematic review. Crit Rev Food Sci Nutr. 2020;60(17):2874-86.
- Rocha BS, Laranjinha J. Nitrate from diet might fuel gut microbiota metabolism: Minding the gap between redox signaling and inter-kingdom communication. Free Radic Biol Med. 2020;149:37-43.
- Kapil V, Khambata RS, Robertson A, Caulfield MJ, Ahluwalia A. Dietary nitrate provides sustained blood pressure lowering in hypertensive patients: a randomized, phase 2, double-blind, placebo-controlled study. Hypertension. 2015;65(2):320-7.
- Bondonno CP, Liu AH, Croft KD, et al. Antibacterial mouthwash blunts oral nitrate reduction and increases blood pressure in treated hypertensive men and women. Am J Hypertens. 2015;28(5):572-5.
- Velmurugan S, Gan JM, Rathod KS, et al. Dietary nitrate improves vascular function in patients with hypercholesterolemia: a randomized, double-blind, placebo-controlled study. Am J Clin Nutr. 2016;103(1):25-38.
- Rosier BT, Buetas E, Moya-Gonzalvez EM, Artacho A, Mira A. Nitrate as a potential prebiotic for the oral microbiome. Sci Rep. 2020;10(1):12895.
- Hyde ER, Andrade F, Vaksman Z, et al. Metagenomic analysis of nitrate-reducing bacteria in the oral cavity: implications for nitric oxide homeostasis. PLoS One. 2014;9(3):e88645.
- Goh CE, Trinh P, Colombo PC, et al. Association between nitrate-reducing oral bacteria and cardiometabolic outcomes: results from origins. J Am Heart Assoc. 2019;8(23):e013324.
- Hansen TH, Kern T, Bak EG, et al. Impact of a vegan diet on the human salivary microbiota. Sci Rep. 2018;8(1):5847.
- Tomova A, Bukovsky I, Rembert E, et al. The effects of vegetarian and vegan diets on gut microbiota. Front Nutr. 2019;6:47.
- Jockel-Schneider Y, Goßner SK, Petersen N, et al. Stimulation of the nitrate-nitrite-NO-metabolism by repeated lettuce juice consumption decreases gingival inflammation in periodontal recall patients: a randomized, double-blinded, placebo-controlled clinical trial. J Clin Periodontol. 2016;43(7):603-8.
- Danser MM, Gómez SM, Van der Weijden GA. Tongue coating and tongue brushing: a literature review. Int J Dent Hyg. 2003;1(3):151-8.
- Seemann R, Conceicao MD, Filippi A, et al. Halitosis management by the general dental practitioner--results of an international consensus workshop. J Breath Res. 2014;8(1):017101.
- Redmond AM, Meiklejohn C, Kidd TJ, Horvath R, Coulter C. Endocarditis after use of tongue scraper. Emerg Infect Dis. 2007;13(9):1440-1.
- Aylıkcı BU, Colak H. Halitosis: From diagnosis to management. J Nat Sci Biol Med. 2013;4(1):14-23.
Motion graphics by Avo Media
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How Tongue Scraping Can Affect Heart Health
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Content URLDoctor's Note
There was so much juicy stuff packed into a single video! Let me emphasize some of the key points. I have tons of videos about our microbiome, but, normally, I’m mostly only talking about the gut microbiome. We have a skin microbiome, good and bad bugs that live on our skin, and affect conditions like acne and eczema, for instance. We have a microbiome in our ear canals, living in our ear wax. And, yes, we have an oral microbiome that doesn’t just determine the health of our gums and teeth, but it also has systemic consequences––converting the nitrates in beets and green leafy vegetables into the “open sesame” nitric oxide molecule that allows our arteries to relax and dilate open.
It’s a team effort. When you hear Dr. Esselstyn talk about the miracle of nitric oxide for your heart, and how heart patients should eat greens six times a day, yes, yes, yes! But, you can’t take full advantage of all of those greens without these good bacteria on your tongue. That’s why antibacterial mouthwash is such a bad idea, and why antibacterial mouthwash is not the way to deal with bad breath––because, when you use it, you’re killing your nitric oxide-producing bugs, too. If you never eat vegetables, it doesn’t matter much either way; but if you want to keep the good bugs happy, follow these three tips:
- Don’t use antibacterial mouthwash.
- Eat a plant-based diet because vegans have more of the good bugs.
- Tongue scrape every day, as regular tongue cleaning boosts the good bacteria, too.
Let’s get to the nitty gritty. What is the best way to clean your tongue? That’s the topic of the last video in this series: How to Clean Your Tongue.
If you missed any of the first three videos, see:
- Effects of Tongue Scraping on Plaque, Gingivitis, and Cavities
- Tongue Scraping vs. Tongue Brushing for Treating Halitosis (Bad Breath)
- Does Tongue Scraping Cause Cancer?
What else are nitrates good for? Check out Best Brain Foods: Greens and Beets Put to the Test.
Check out my newer videos on this topic: How to Get Rid of Garlic Breath and Green Tea as a Mouthwash for Halitosis (Bad Breath)
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