Is Your Mouthwash Increasing Your Blood Pressure?

For most of my life I used antibacterial mouthwash, and I chose antibacterial on purpose. I was already brushing. The rinse was extra insurance against gingivitis, because gum disease is associated with heart disease.^43,44 What I didn't know is that bacteria living on my tongue are part of how my body makes nitric oxide, the signal my arteries use to relax.

I have personal reasons to pay attention to nitric oxide. I've had borderline-high blood pressure most of my adult life, usually upper 120s to mid 130s over mid 80s. Not horrible, but the kind I wrote about in the blood pressure post that gets waved off at a yearly physical. I carry one copy of a common variant in NOS3, the gene for the enzyme my artery lining uses to make nitric oxide.¹ And in August, in the cath lab, my right coronary artery clamped down on its own. The report reads "Moderate (30-50% diameter stenosis) diffuse right coronary stenosis," and after nitroglycerin, "there was no stenosis." I told that story in the vasospasm post.

It's also part of my job. We give nitroglycerin in the ER, and it works fast, but it isn't a long-term fix. When healthy young men wore nitroglycerin patches around the clock for six days, their artery lining's own ability to relax the artery was still blunted three hours after the patches came off.² So I've been hunting for natural ways to support nitric oxide, and that series is coming. The easiest place to start is to stop doing the things that shut it down.

So, is your mouthwash increasing your blood pressure?

The Bottom Line

Some antibacterial rinses shut down a pathway your body built on purpose. Your salivary glands pull nitrate from your food out of your blood and concentrate it in your saliva. Bacteria on the back of your tongue turn it into nitrite, and your body turns the nitrite into nitric oxide, the signal your arteries use to relax. A week of chlorhexidine, the antiseptic rinse dentists prescribe after gum surgery, cut the mouth's nitrite production by 90 percent.³

Whether that raises your blood pressure is less settled. Single trials found rises of 2 to 3.5 mmHg (millimeters of mercury, the unit on your cuff reading).³ Pooled together, the trials show a small rise that isn't statistically significant; the data fit anything from no change to a few points.^4,5 It also depends on what's in the bottle. In the most direct head-to-head comparison of commercial rinses, an essential-oil rinse behaved like plain water on nitrite, while a cetylpyridinium chloride (CPC) rinse and a chlorhexidine rinse cut it.⁶ No study here measured heart attacks or strokes.

My read: the blood pressure studies go back and forth, and the mechanism doesn't. Before you buy anything to raise your nitric oxide, stop doing the thing that shuts it down. The tongue loop is also a clean example of dysbiosis, one of the twelve hallmarks of aging.⁷ If your dentist prescribed chlorhexidine, keep using it as directed, and ask before you stop.

Vocabulary that matters

• Nitrate (NO₃⁻). Nitrogen bound to three oxygens. About 80 percent of the nitrate you eat comes from vegetables.⁸
• Nitrite (NO₂⁻). Nitrate with one oxygen removed. Tongue bacteria make it, and your body can turn it into nitric oxide.
• Nitric oxide (NO). A gas your arteries use as a signal to relax. It also keeps platelets from sticking to the vessel wall.
• Dysbiosis. A community of microbes pushed out of balance in a way that changes how your own body works.

How did anyone figure this out?

Nitrate and nitrite were medicines long before anyone understood the chemistry, and long before they were villains; a 2008 history in Circulation traces their medical use back through the centuries.⁹ William Murrell was treating angina with nitroglycerin by 1876, decades before anyone understood how it worked, and Alfred Nobel, who made his fortune turning it into dynamite, had angina himself and refused to take it.¹⁰ In the 1970s, the nitrite in saliva was studied as a possible route to cancer-causing compounds called nitrosamines.¹¹ In 1987, two labs showed that the artery lining relaxes the muscle around it with nitric oxide.^12,13 In 1994, researchers measured nitric oxide forming in the acidic human stomach,¹⁴ and in 1995 a second group traced the nitrate-to-nitrite step, in rats, to bacteria at the back of the tongue. The title of that 1995 paper already used the loop's name, the enterosalivary circulation: gut ("entero") to saliva and back.¹⁵ The chemistry once studied as a cancer risk turned out to be one of the ways your body keeps its blood pressure down.

How does nitrate from food become nitric oxide?

1. You eat nitrate, mostly from vegetables.⁸
2. It's absorbed into your blood. Your salivary glands pull up to 25 percent of it back out, concentrating it 10 to 20 times higher in saliva than in blood.¹⁶
3. Bacteria at the back of your tongue make nitrite. Researchers found nitrate reduction "concentrated at the rear of the tongue dorsal surface," the top of the tongue toward the throat, mostly by Veillonella, Actinomyces and Rothia species.¹⁷ Your own cells do little of this step.¹⁸
4. You swallow. Some of the nitrite becomes nitric oxide in your acidic stomach.^14,15
5. The rest circulates as nitrite, and your tissues turn it into nitric oxide, especially where oxygen is low.^19,20

How do we know the mouth step matters? Researchers made people spit. In 2004, a dose of nitrate raised blood nitrite 4-fold, unless the volunteers avoided swallowing their saliva, and then the rise didn't happen.²¹ In 2008, 500 mL of beetroot juice lowered blood pressure by as much as 10.4/8 mmHg about three hours later. When six volunteers spat out all their saliva for three hours instead of swallowing it, blood nitrite didn't rise and blood pressure didn't fall.²²

Your body has two main routes to nitric oxide. In the artery lining, an enzyme called eNOS builds it from the amino acid arginine, using oxygen.²³ Block nitric oxide production and blood pressure climbs; in 1993, infusing a nitric oxide synthase blocker raised healthy volunteers' mean arterial pressure, the average across a heartbeat, by 10 percent.²⁴ The nitrate route works best where oxygen is scarce, exactly where the enzyme route struggles, which makes it something like a backup generator.²³ Citrulline, which your body recycles into arginine, feeds the enzyme route; I covered it in the research note on metformin and citrulline.

That's why this matters to me personally. My NOS3 variant lowered the gene's activity in a lab test, and in a 1999 study from Japan it was more common in people with coronary spasm.²⁵ If it means my artery lining makes somewhat less nitric oxide, the tongue route carries a bigger share of my load. That's my reasoning, not a tested result. The spasm link rests on one study, and the two largest meta-analyses on the variant and blood pressure disagree: one found a small effect, and the other found none and warned of publication bias.^26,27

Why does nitric oxide matter so much? It's one of the main ways your artery lining talks to the cells around it. It relaxes the muscle in the artery wall^12,13 and keeps platelets from sticking.²⁸ That conversation between cells is its own hallmark of aging, altered intercellular communication, and the subject of the endothelial post later in this series. The tongue loop adds a second one, dysbiosis: a community of microbes doing a job your body depends on. Push that community off balance and one measurable pathway changes.

Does mouthwash reduce nitric oxide?

Does a rinse shut down the tongue step?

Yes. In 2008, seven volunteers rinsed with chlorhexidine before a dose of nitrate. The rinse didn't change how much nitrate reached their saliva or blood. It stopped the saliva from turning nitrate into nitrite, and the rise in blood nitrite was much smaller.²⁹ In the 2013 trial everyone cites, a week of chlorhexidine in 19 healthy volunteers cut the mouth's nitrite production by 90 percent and blood nitrite by 25 percent.³

Does mouthwash raise blood pressure?

Sometimes, by a little. In that 2013 trial, systolic and diastolic pressure (the top and bottom numbers) rose by 2 to 3.5 mmHg, an effect that appeared within a day and held for the week, tracking the fall in blood nitrite.³ A smaller trial found a 2.3 mmHg systolic rise after three days in people already treated for high blood pressure.³⁰ In a one-arm study of 26 healthy people, a week of chlorhexidine raised systolic pressure significantly in those who cleaned their tongue twice a day, while the group as a whole moved from 113 to 115 mmHg.³¹ That result is why I stopped scraping my tongue. It's my own call; nobody has tested whether that helps.

Pooled, the picture softens. One meta-analysis, a study that combines earlier trials, pooled five crossover trials, where each person tried both the rinse and a comparison, and found an average systolic rise of 1.59 mmHg that was not statistically or clinically significant.⁴ A 2026 review of chlorhexidine alone pooled four studies: a 1.56 mmHg difference, with plausible values running from slightly below zero to 3.8 mmHg.⁵ Neither proves there's no effect. Both say that if there is one, it's small.

You may have seen scarier headlines. In a Puerto Rican cohort of overweight and obese adults aged 40 to 65, people who rinsed at least twice a day developed prediabetes or diabetes at a 55 percent higher rate over three years than less frequent users, and had an 85 percent higher rate of a new hypertension diagnosis, though blood pressure measured at a single visit showed no link.^32,33 Those are observational studies. They can't show the rinse caused anything, and their summaries don't say which rinses people used.

The nitrate side isn't a guaranteed lever either. Short trials of dietary nitrate lowered systolic pressure by 4.4 mmHg on average,³⁴ but a five-week Swedish trial in 243 people aged 50 to 70 with elevated blood pressure found that 300 mg of nitrate a day, from leafy greens or from pills, did no better than a placebo.³⁵

Does every mouthwash do this?

Not in the most direct head-to-head test. In 2016, 12 healthy men drank beetroot juice and then rinsed every hour with one of three commercial mouthwashes or with water. On nitrite, the essential-oil rinse grouped with water, while the CPC rinse grouped with chlorhexidine.⁶ That's one trial of 12 men over four hours, and nobody has tested years of daily use. What it does tell you is to read the active ingredient on the label, not the word "antibacterial" and not the brand.

The Read The blood pressure studies go back and forth. The mechanism doesn't. Chlorhexidine reliably shuts down the tongue bacteria's half of this pathway, a CPC rinse did the same in that four-hour head-to-head trial, and no study has measured what that does to heart attacks. I wouldn't shut down bacteria doing a job my body mostly can't do itself just to freshen my breath.

The nitrate lottery

If you want more nitrate, eat more vegetables. How much will you get? It depends, a lot.

Researchers in Italy tested 22 samples of fresh wild rocket, the peppery arugula, bought from local stores. The lowest had 1,121.6 mg of nitrate per kilogram and the highest had 7,311.2, more than six-fold apart.³⁶ By my arithmetic, the 300 mg a day used in the Swedish trial would take about 267 grams (9.4 ounces) of the low sample and about 41 grams (1.4 ounces) of the high one. That's an illustration, not a daily target. The Italian team points to the plant's genetics, light, temperature, how it was grown, and nitrogen fertilizer, used in "extremely variable" amounts,³⁶ and cooking vegetables in water can lower their nitrate.³⁷ None of that makes vegetables a bad source. A food doesn't have to be dosed like a pill to be useful.

What about beetroot supplements? A label that says beetroot extract does not tell you how much nitrate is in it. A 2019 study of 24 beetroot juice products sold to athletes found about a 50-fold range in nitrate, and the same product varied from batch to batch by 30 percent on average.³⁸ A 2023 study of 50 beetroot supplements on the Polish market found 0.197 to 169 mg of nitrate per daily dose. Only 4 of the 50 listed nitrate on the label, and a serving of plain beetroot delivered more nitrate than most of the supplements' daily doses.³⁹ In the US, nitrate isn't among the nutrients a Supplement Facts label has to list.⁴⁰

So what should you do?

• If your dentist prescribed chlorhexidine, use it as directed. After gum and implant surgery it reduced plaque and bleeding in clinical trials.⁴¹ Ask before you stop.
• Read the active ingredient. Chlorhexidine and CPC are the ones with evidence that they cut this pathway; the essential-oil rinse in the head-to-head trial behaved like water.⁶
• Don't give up on your gums. An essential-oil rinse reduced plaque and gum inflammation in four six-month trials,⁴² and gum disease tracks with heart disease, though in 2012 the American Heart Association concluded the link wasn't proven to be cause and effect,⁴³ and its 2025 update is still calling for more research.⁴⁴
• If you stop, the bacteria come back. After a week of chlorhexidine ended, nitrate reducers on the tongue returned in greater numbers. That same small study suggested regular tongue cleaning, with enough dietary nitrate, might help, so don't give up tongue scraping on my account.³¹
• Eat the vegetables, and mix them. Arugula, spinach, lettuce, celery and beetroot. Eat some of them raw; cooking in water can pull nitrate out.³⁷

Know someone who uses mouthwash every day? Send them this. The active ingredient is worth checking.

What I changed

These days I use an essential-oil rinse, the type that behaved like water on nitrite in the head-to-head trial, and I still keep it off the back of my tongue. I lean forward over the sink, work it between my teeth and along my gums, and rinse with plain water right away. Saliva moves, so some of it reaches my tongue anyway. Nobody has tested this; it's my best guess from where the bacteria live.¹⁷ I also stopped scraping my tongue, because of the tongue-cleaning study above.

The Calibrated Claim Audit

Claim	Evidence	My read
Mouthwash raises your blood pressure	A week of chlorhexidine: +2 to 3.5 mmHg 3; pooled: not significant 4,5	Small and inconsistent.
Mouthwash shuts down the tongue's nitrate step	Chlorhexidine cut oral nitrite production 90% 3	Solid mechanism.
All mouthwash does it	Essential-oil rinse grouped with water; CPC and chlorhexidine cut nitrite 6	Depends on the active ingredient.
Mouthwash causes diabetes and hypertension	Twice-daily users had higher rates of both 32,33	Observational. Can't show cause.

Commercial distortion risk: moderate. The incentive ecosystems here are mouthwash makers and the nitric oxide supplement market. Three disclosures I checked: an author of the 2019 tongue-cleaning study founded a nitric oxide supplement company and receives royalties on nitric oxide patents;³¹ the 2026 chlorhexidine review says it was sponsored in part by an unrestricted educational grant from Haleon, a consumer-health company, which the authors say had no say in the design but approved the content of the manuscript, while the same paper's conflict-of-interest section says no funding was accepted beyond the authors' institutions, and the senior authors' research group reports past fees or grants from manufacturers of dental care products;⁵ and that same review notes that two authors of one of the trials it pooled were named as co-inventors on patent applications for therapeutic nitrate.⁵ None of that makes a result wrong. All of it is a reason to read carefully.

The Final Signal

• What the claim gets right: chlorhexidine shuts down the tongue bacteria's conversion of nitrate to nitrite, and a CPC rinse cut it in the head-to-head trial.
• What it gets wrong: the blood pressure effect is small, inconsistent, and depends on what's in the bottle.
• What I changed: my rinse, how I use it, and no more tongue scraping.
• What would change my mind: a longer trial of everyday rinsing showing a blood pressure rise that holds up, or any trial that measures heart attacks and strokes.
• What's next: the twelve hallmarks of aging.

More on nitric oxide and the artery lining: the Cardiovascular Risk series, and the Interventions posts on what a habit actually does to the biology.

Where we head next

Next week we turn to the root cause of all of this, and by all of this I mean chronic disease: plaque in your big arteries, dysfunction in your small ones, diabetes, kidney disease, Alzheimer's. Every one of those has earned an official name in medicine, and underneath the names they are driven in large part by the same root biological processes. Those processes have a name, and I have tossed it around here and there: the hallmarks of aging, twelve processes that weave together to drive aging and disease at the molecular level.⁷ You won't hear your doctor talking with you about this at your next office visit, which is exactly why we are heading there. To understand a disease, a proposed treatment, a new supplement, or a biohack, you need to know which hallmarks it touches and how, and then whether there is anything you can do about it with the options available today. Stay tuned.

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References

1. NCBI dbSNP. Reference SNP rs2070744 (NOS3 T-786C), population allele frequencies. Link [Finding: Population data show the -786C allele is common: 23.4 percent of alleles in the 1000 Genomes Project and 29.9 percent in gnomAD genomes, read from the dbSNP record on 2026-10-03. A database lookup, not a study.]
2. Gori T, Harvey P, Floras JS, Parker JD. Continuous therapy with nitroglycerin impairs endothelium-dependent vasodilation but does not cause tolerance in conductance arteries: a human in vivo study. J Cardiovasc Pharmacol. 2004;44(5):601-606. PMID: 15505499 [Finding: Sixteen young men were randomized to six days of continuous nitroglycerin patches or no treatment. In the patch group, flow-mediated dilation was still blunted three hours after patch removal (8.7% before, 4.1% after), though classic tolerance did not develop in that artery.]
3. Kapil V, Haydar SMA, Pearl V, Lundberg JO, Weitzberg E, Ahluwalia A. Physiological role for nitrate-reducing oral bacteria in blood pressure control. Free Radic Biol Med. 2013;55:93-100. PMID: 23183324 [Finding: In 19 healthy volunteers, a week of chlorhexidine mouthwash cut oral nitrite production by 90% and plasma nitrite by 25%, and systolic and diastolic pressure rose 2 to 3.5 mmHg, appearing within a day and holding for the week. Small, short, healthy volunteers.]
4. Farook FF, Alnasyan B, Alhamid R, et al. Association between mouth rinse use and changes in blood pressure: a systematic review and meta-analysis with trial sequential analysis. Int J Dent Hyg. 2024;22(1):65-77. PMID: 37486884 [Finding: Pooling five crossover trials, mouth rinse use raised systolic pressure by 1.59 mmHg on average (95% CI -0.15 to 3.33), not statistically or clinically significant; the authors urge caution because the trials were inconsistent.]
5. Toonen LSJ, Van Swaaij BWM, Vagevuur ML, Van der Weijden FGA, Timmerman MF, Slot DE. The effect of chlorhexidine mouthwash on blood pressure: a systematic review and meta-analysis. Int J Dent Hyg. 2026;24(3):390-403. PMID: 41820203 [Finding: Five chlorhexidine studies were reviewed and four were pooled; two showed significant rises on their own, but the pooled systolic difference (1.56 mmHg, 95% CI -0.67 to 3.80, P=0.17) was not significant. Its funding statement says it was sponsored in part by an unrestricted educational grant from Haleon, which had no say in the design but approved the content of the manuscript, while its conflict-of-interest section says no funding was accepted beyond the authors' institutions; the senior authors' group has received fees or grants from dental-care manufacturers.]
6. Woessner M, Smoliga JM, Tarzia B, Stabler T, Van Bruggen M, Allen JD. A stepwise reduction in plasma and salivary nitrite with increasing strengths of mouthwash following a dietary nitrate load. Nitric Oxide. 2016;54:1-7. PMID: 26778277 [Finding: In 12 healthy men given beetroot juice, the essential-oil rinse grouped with water on salivary and plasma nitrite, while the cetylpyridinium chloride and chlorhexidine rinses lowered it. One small, four-hour trial.]
7. López-Otín C, Blasco MA, Partridge L, Serrano M, Kroemer G. Hallmarks of aging: an expanding universe. Cell. 2023;186(2):243-278. PMID: 36599349 [Finding: Proposes twelve hallmarks of aging, including altered intercellular communication, chronic inflammation and dysbiosis. A framework review, not an experiment.]
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13. Ignarro LJ, Buga GM, Wood KS, Byrns RE, Chaudhuri G. Endothelium-derived relaxing factor produced and released from artery and vein is nitric oxide. Proc Natl Acad Sci U S A. 1987;84(24):9265-9269. PMID: 2827174 [Finding: Independently identified the same factor as nitric oxide.]
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15. Duncan C, Dougall H, Johnston P, et al. Chemical generation of nitric oxide in the mouth from the enterosalivary circulation of dietary nitrate. Nat Med. 1995;1(6):546-551. PMID: 7585121 [Finding: In rats, nitrate reduction was confined to a bacteria-colonized zone at the back of the tongue and absent in germ-free rats; in humans, nitrate intake raised nitric oxide in the mouth.]
16. Qu XM, Wu ZF, Pang BX, Jin LY, Qin LZ, Wang SL. From nitrate to nitric oxide: the role of salivary glands and oral bacteria. J Dent Res. 2016;95(13):1452-1456. PMID: 27872324 [Finding: A review stating that up to 25% of circulating nitrate is taken up by the salivary glands, raising its concentration in saliva 10- to 20-fold. A review, not the original measurement.]
17. Doel JJ, Benjamin N, Hector MP, Rogers M, Allaker RP. Evaluation of bacterial nitrate reduction in the human oral cavity. Eur J Oral Sci. 2005;113(1):14-19. PMID: 15693824 [Finding: In 10 healthy people, nitrate reduction varied between individuals and was concentrated at the rear of the top surface of the tongue; Veillonella species were the most common reducers cultured.]
18. 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. PMID: 24670812 [Finding: Gene sequencing of tongue scrapings from six volunteers identified 14 candidate nitrate-reducing species; the authors note humans lack this enzyme activity.]
19. Kapil V, Khambata RS, Jones DA, et al. The noncanonical pathway for in vivo nitric oxide generation: the nitrate-nitrite-nitric oxide pathway. Pharmacol Rev. 2020;72(3):692-766. PMID: 32576603 [Finding: A comprehensive review describing nitrite as a storage form of nitric oxide that releases it preferentially under acidic or low-oxygen conditions.]
20. Cosby K, Partovi KS, Crawford JH, et al. Nitrite reduction to nitric oxide by deoxyhemoglobin vasodilates the human circulation. Nat Med. 2003;9(12):1498-1505. PMID: 14595407 [Finding: Nitrite infused into the forearm artery increased blood flow in humans; deoxygenated hemoglobin converted nitrite to nitric oxide.]
21. Lundberg JO, Govoni M. Inorganic nitrate is a possible source for systemic generation of nitric oxide. Free Radic Biol Med. 2004;37(3):395-400. PMID: 15223073 [Finding: A nitrate dose raised plasma nitrite 4-fold, but the rise was prevented when volunteers avoided swallowing their saliva, showing it depends on the mouth.]
22. Webb AJ, Patel N, Loukogeorgakis S, et al. Acute blood pressure lowering, vasoprotective, and antiplatelet properties of dietary nitrate via bioconversion to nitrite. Hypertension. 2008;51(3):784-790. PMID: 18250365 [Finding: 500 mL of beetroot juice lowered blood pressure by up to 10.4/8 mmHg about three hours later in healthy volunteers; in six volunteers who spat out their saliva for three hours, the nitrite rise and the blood pressure drop did not occur.]
23. Lundberg JO, Weitzberg E, Gladwin MT. The nitrate-nitrite-nitric oxide pathway in physiology and therapeutics. Nat Rev Drug Discov. 2008;7(2):156-167. PMID: 18167491 [Finding: The landmark review describing nitrate and nitrite as an alternative source of nitric oxide to the classical arginine enzyme pathway, especially when oxygen is low.]
24. Haynes WG, Noon JP, Walker BR, Webb DJ. Inhibition of nitric oxide synthesis increases blood pressure in healthy humans. J Hypertens. 1993;11(12):1375-1380. PMID: 7510736 [Finding: In eight healthy people, blocking nitric oxide production raised mean arterial pressure by 10% and total peripheral resistance by 46%.]
25. Nakayama M, Yasue H, Yoshimura M, et al. T-786→C mutation in the 5'-flanking region of the endothelial nitric oxide synthase gene is associated with coronary spasm. Circulation. 1999;99(22):2864-2870. PMID: 10359729 [Finding: In Japanese patients, the variant was more common with coronary spasm than in controls, and it reduced eNOS gene promoter activity in a lab assay. One study, one population, and the reported risk factor is the variant allele, not a per-genotype result.]
26. Xie X, Shi X, Xun X, Rao L. Endothelial nitric oxide synthase gene single nucleotide polymorphisms and the risk of hypertension: a meta-analysis involving 63,258 subjects. Clin Exp Hypertens. 2017;39(2):175-182. PMID: 28287883 [Finding: A meta-analysis of 95 case-control studies of two eNOS variants, 63,258 subjects in all. For T-786C the authors report the C allele conferred increased susceptibility to hypertension (T versus C, OR 0.92, 95% CI 0.87 to 0.97), with positive results in the Asian subgroup. Disagrees with the 2007 meta-analysis.]
27. Pereira TV, Rudnicki M, Cheung BM, et al. Three endothelial nitric oxide (NOS3) gene polymorphisms in hypertensive and normotensive individuals: meta-analysis of 53 studies reveals evidence of publication bias. J Hypertens. 2007;25(9):1763-1774. PMID: 17762636 [Finding: Across 53 studies and 40,413 people, no effect of T-786C on hypertension was detected, and the authors found evidence of publication bias in the field.]
28. Radomski MW, Palmer RMJ, Moncada S. Endogenous nitric oxide inhibits human platelet adhesion to vascular endothelium. Lancet. 1987;2(8567):1057-1058. PMID: 2889967 [Finding: In cultured endothelial cells, nitric oxide release reduced the adhesion of human platelets, evidence that the artery lining's non-stick surface depends on nitric oxide.]
29. Govoni M, Jansson EÅ, Weitzberg E, Lundberg JO. The increase in plasma nitrite after a dietary nitrate load is markedly attenuated by an antibacterial mouthwash. Nitric Oxide. 2008;19(4):333-337. PMID: 18793740 [Finding: In seven volunteers, a chlorhexidine rinse before a nitrate dose abolished the conversion to nitrite in saliva and markedly blunted the rise in plasma nitrite.]
30. 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):572-575. PMID: 25359409 [Finding: In 15 treated hypertensive adults, three days of antibacterial mouthwash raised systolic pressure 2.3 mmHg versus water; diastolic pressure did not change and the fall in plasma nitrite was only a trend.]
31. 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. PMID: 30881924 [Finding: In a one-arm study of 26 healthy people, a week of twice-daily chlorhexidine raised systolic pressure significantly in the subgroup who cleaned their tongue twice a day, while the whole group moved from 113 to 115 mmHg; after it ended, nitrate-reducing bacteria on the tongue were enriched, and tongue-cleaning frequency predicted the response. One author discloses founding a nitric oxide supplement company.]
32. Joshipura KJ, Muñoz-Torres FJ, Morou-Bermudez E, Patel RP. Over-the-counter mouthwash use and risk of pre-diabetes/diabetes. Nitric Oxide. 2017;71:14-20. PMID: 28939409 [Finding: In 945 overweight or obese adults followed for three years, twice-daily mouthwash users developed prediabetes or diabetes at a higher rate than less frequent users (IRR 1.55). Observational.]
33. Joshipura K, Muñoz-Torres F, Fernández-Santiago J, Patel RP, Lopez-Candales A. Over-the-counter mouthwash use, nitric oxide and hypertension risk. Blood Press. 2020;29(2):103-112. PMID: 31709856 [Finding: In 540 adults followed for three years, twice-daily mouthwash use was associated with more self-reported hypertension diagnoses (IRR 1.85), but blood pressure measured at a single visit showed no association. Observational.]
34. Siervo M, Lara J, Ogbonmwan I, Mathers JC. Inorganic nitrate and beetroot juice supplementation reduces blood pressure in adults: a systematic review and meta-analysis. J Nutr. 2013;143(6):818-826. PMID: 23596162 [Finding: Sixteen crossover trials (254 participants, 2 hours to 15 days) found systolic pressure fell 4.4 mmHg on average with inorganic nitrate or beetroot juice.]
35. Sundqvist ML, Larsen FJ, Carlström M, et al. A randomized clinical trial of the effects of leafy green vegetables and inorganic nitrate on blood pressure. Am J Clin Nutr. 2020;111(4):749-756. PMID: 32091599 [Finding: In 243 adults aged 50 to 70 with elevated blood pressure, five weeks of 300 mg nitrate a day from leafy greens or potassium nitrate pills did not lower 24-hour systolic pressure versus placebo.]
36. Iammarino M, Berardi G, Vita V, et al. Determination of nitrate and nitrite in Swiss chard and wild rocket and food safety evaluations. Foods. 2022;11(17):2571. PMID: 36076757 [Finding: Twenty-two fresh wild rocket samples ranged from 1,121.6 to 7,311.2 mg nitrate per kg; the authors list genotype, light, temperature, cultivation and nitrogen fertilizer as drivers.]
37. Chan TY. Vegetable-borne nitrate and nitrite and the risk of methaemoglobinaemia. Toxicol Lett. 2011;200(1-2):107-108. PMID: 21075182 [Finding: A short commentary noting that cooking in water or blanching, peeling, and removing stems and midribs can lower vegetable nitrate.]
38. Gallardo EJ, Coggan AR. What's in your beet juice? Nitrate and nitrite content of beet juice products marketed to athletes. Int J Sport Nutr Exerc Metab. 2019;29(4):345-349. PMID: 30299195 [Finding: Across 24 products from 21 companies, nitrate varied about 50-fold between products, and batch-to-batch variation averaged 30% (range 2 to 83%).]
39. Brzezińska-Rojek J, Sagatovych S, Malinowska P, et al. Antioxidant capacity, nitrite and nitrate content in beetroot-based dietary supplements. Foods. 2023;12(5):1017. PMID: 36900534 [Finding: Across 50 beetroot supplements, nitrate per daily dose ranged from 0.197 to 169 mg; only 4 declared nitrate on the label, and a serving of fresh beetroot provided more nitrate than most daily portions of the supplements.]
40. US Code of Federal Regulations. 21 CFR §101.36, Nutrition labeling of dietary supplements. Cornell Legal Information Institute. Link [Finding: The nutrients a Supplement Facts panel must list; nitrate is not among them.]
41. Solderer A, Kaufmann M, Hofer D, et al. Efficacy of chlorhexidine rinses after periodontal or implant surgery: a systematic review. Clin Oral Investig. 2019;23(1):21-32. PMID: 30535817 [Finding: Across 11 publications, chlorhexidine after gum or implant surgery reduced plaque and bleeding compared with placebo.]
42. Van Leeuwen MP, Slot DE, Van der Weijden GA. The effect of an essential-oils mouthrinse as compared to a vehicle solution on plaque and gingival inflammation: a systematic review and meta-analysis. Int J Dent Hyg. 2014;12(3):160-167. PMID: 24720368 [Finding: Across four six-month trials, an essential-oil rinse gave significantly better plaque control and less gum inflammation than an alcohol vehicle solution.]
43. Lockhart PB, Bolger AF, Papapanou PN, et al. Periodontal disease and atherosclerotic vascular disease: does the evidence support an independent association? A scientific statement from the American Heart Association. Circulation. 2012;125(20):2520-2544. PMID: 22514251 [Finding: Observational studies support an association between gum disease and atherosclerotic disease independent of known confounders, but do not support a causal relationship, and there is no evidence that periodontal treatment prevents it.]
44. Tran AH, Zaidi AH, Bolger AF, et al. Periodontal disease and atherosclerotic cardiovascular disease: a scientific statement from the American Heart Association. Circulation. 2026;153(6):e73-e88, published online December 16, 2025. PMID: 41399933 [Finding: The AHA's update of its 2012 statement, synthesizing newer evidence including Mendelian randomization studies, which use inherited gene variants to test cause and effect, and periodontal treatment trials. Its abstract says the statement identifies areas needing further clarification that would benefit from additional research.]