How to Increase Nitric Oxide Without Breaking the Pathway

To increase nitric oxide, eat green leafy vegetables daily for nitrate. Protect the tongue bacteria that convert it by dropping a daily antiseptic mouthwash habit. Skip reheated frying oil, which damages the enzyme your vessels use. The target is a working vessel lining and bacterial backup, not a higher reading.

Look at your bathroom counter. Does an antiseptic mouthwash sit there and get used twice a day? Then you may be switching off one of the body’s own routes to nitric oxide. Meanwhile you shop for a supplement to raise it. Anyone asking how to increase nitric oxide should start with what is breaking the pathway.

Your Gut Is Suffocating, playing above, draws on The Angry Gut. That is the book by Dr. Gurpreet Singh Padda, MD, MBA, MHP, with Ami Michelle Grimes. It argues that blood vessels feed the gut wall from behind, and those vessels depend on this molecule. Here the focus is the terrain. What feeds the pathway? What poisons it? And what can the tests tell you, and what can they not?

Is more nitric oxide always better?

Nitric oxide is not one thing. Your vessel lining makes a steady trickle to keep small arteries open. Your gut, the first brain, needs that supply to get blood. An inflammatory enzyme makes a flood. Measured in the rectum, healthy people ran a median 45 ppb of nitric oxide. Active inflammatory bowel disease ran 3475 ppb (Reinders et al., 2005). An inflamed gut can be drowning in the molecule while its vessels starve for it.

So the target is not a higher reading. It is a working endothelium (vessel lining) plus a working bacterial backup. Most modern habits quietly wear down both sources. This is the blood vessel face of metabolic inflammation.

How does your body make nitric oxide from food?

Most dietary nitrate, about 80%, comes from green leafy vegetables. After you absorb it, roughly 70%-75% of the nitrate in your blood leaves in urine. The other 20-25% is pumped back into saliva at 20-25-fold strength by the sodium/iodide symporter, a pump in the salivary glands (Picozzi et al., 2025). Human cells cannot convert nitrate to nitrite. Bacteria can, mostly in the sheltered grooves at the back of the tongue.

That makes a patch of your tongue a working part of your blood flow. The proof is blunt. Give people a dose of nitrate with and without an antibacterial rinse. Nitrate in saliva and blood stays the same. But the conversion to nitrite disappears (Govoni et al., 2008). The bacteria are the step, not an extra.

This is where nitric oxide foods earn their name. Leafy greens supply the raw material. But only a living mouth community turns it into something your vessels can use.

Mouthwash and blood pressure: what the trials show

Researchers gave 19 healthy volunteers a week of antiseptic mouthwash. Nitrite made in the mouth dropped 90%, and nitrite in the blood dropped 25%. Blood pressure rose by 2-3.5 mmHg in step with the drop in blood nitrite (Kapil et al., 2013). In a cohort (group) study, people who used mouthwash twice daily or more got new high blood pressure at a rate ratio of 1.85 (Joshipura et al., 2020).

The strongest argument against deserves its full size. A 2026 meta-analysis pooled trials of chlorhexidine, a common antiseptic rinse. It found top blood pressure moved 1.56 mmHg, with a range running from minus 0.67 to 3.80. It judged the change negligible (Toonen et al., 2026). Only five trials qualified, and two of them found a significant rise. That range easily holds the rises seen in single studies. The trials also tested a rinse added for days, in people using it as prescribed.

Nobody has randomly assigned long-term twice-daily users to stop. That trial would be cheap. Until it exists, the habit has only been watched, never taken away. Our position is practical. An antiseptic rinse has a job: a set course around a dental procedure or infection. A daily habit measured in years is a different exposure.

Is nitrate from vegetables different from nitrate in processed meat?

The same ion acts differently depending on what carries it. Over 27 years, 52,247 Danes had their nitrate intake split by source. Nitrate from plants carried a hazard ratio of 0.83 for death from any cause. Nitrate from animal foods ran 1.09. Nitrate from meat allowed to contain additives ran 1.19, and from tap water 1.19 (Bondonno et al., 2024).

That is observational data. The authors could not pin the difference on smoking or antioxidant vitamins. The practical reading is simple anyway. Get nitrate from vegetables, not from processed meat. Do not assume a nitrate supplement does what a plate of greens does.

What depletes nitric oxide in your blood vessels?

The other way to lose nitric oxide in your vessels is to damage the enzyme that makes it. Oxidized LDL is cholesterol-carrying fat that has gone rancid in the body. It binds a receptor on the vessel lining that drives superoxide production. Superoxide is a harsh radical. It destroys nitric oxide. It also uncouples its enzyme, which throws the enzyme off track. Diet is one source of that oxidized fat.

A pooled study covered 68,659 people. Higher blood linoleic acid, the marker of vegetable oil intake, went with fewer heart and vessel deaths, at a hazard ratio of 0.78 (Marklund et al., 2019). But the test measures the share of linoleic acid that is still intact, taken once. Any molecule destroyed by oxidation before or after it was eaten is invisible to that test by design. It shows the part that survived, not the part that went rancid.

When somebody measured the oil itself, the picture changed. Researchers sampled kitchen oil from 538 households. The more the frying oil had broken down, the more high blood pressure they found. The link held after adjusting for age, sex, obesity and blood sugar handling (Soriguer et al., 2003). In rats fed soy oil for six months, the main artery relaxed near normal on fresh oil. It fell step by step with reheating, to 68% in the group fed oil reheated ten times. Blood nitric oxide products fell on heated oil (Leong et al., 2010). The more often the oil was reheated, the worse the arteries did.

Money decides who eats the damaged version. Reused oil is cheaper oil, and the cheapest fryers change it least often. The terrain of a vessel wall reflects income as much as intention.

How to increase nitric oxide, one habit at a time

Each repair has a body-based reason. Eat green leafy vegetables daily, because they supply the nitrate your tongue bacteria convert. Keep that community alive by saving antiseptic rinse for a set course. Cook with real olive oil, butter or tallow, not seed oils, and never reheat frying oil, because the enzyme that opens your arteries is sensitive to oxidized fat. Stop treating a supplement as a substitute for any of the three.

The pathway is measured in humans. The rinse effects come from small trials and group studies. The oil harm rests on household and rat data. Trials often leave out the patient with heavy metabolic disease, and we apply the mechanism to that patient. The Chapter 9 Deep Dive carries every study and its full numbers. It covers what each does not show and what would change our minds. A fuller metabolic audit is how we check whether your body can deliver repair. The membranes those vessels feed are the subject of the omega-6 to omega-3 ratio. Vitamin D as a hormone follows what blood delivers next.

Frequently asked questions

Does mouthwash raise blood pressure?

Antiseptic mouthwash wipes out the tongue bacteria that turn dietary nitrate into nitrite. In healthy volunteers, a week of use cut nitrite made in the mouth by 90%. It nudged blood pressure up by a few points. In a group study, heavy use tracked with new high blood pressure. A pooled analysis judged the average change small. A short prescribed course differs from years of habit. Why the body feels older after 50 shows how small losses add up.

What foods increase nitric oxide?

Green leafy vegetables are the main food source of nitrate, supplying about 80% of it. Your body concentrates nitrate into saliva. Bacteria at the back of the tongue convert it. So the food only works if that community is intact. In a large Danish cohort study, nitrate from plants tracked lower death rates. Nitrate from processed meat did not. Metabolic optimization puts food choices into a measured plan.

Is vegetable oil bad for your blood vessels?

For our patients, yes. Seed oils are rich in omega-6 linoleic acid, and they go rancid with storage and reheating. Cohort studies that link intact blood linoleic acid to fewer heart and vessel deaths cannot see the oil that has already broken down. Broken-down household frying oil tracked high blood pressure. Rats fed oil reheated over and over lost artery relaxation. Cook with real olive oil, not seed oils. How the modern plate inflames the brain covers the same chemistry upstream.

What is endothelial dysfunction?

It is when the lining of your blood vessels fails to make enough nitric oxide to open on demand. Raw materials can run short, or oxidized fat can damage the enzyme. Then the enzyme makes a harsh radical instead of nitric oxide. The result is tissue that gets too little blood when it needs more. That includes the gut after a meal. Why you cannot out-inject a broken metabolism explains why supply matters for repair.

Do nitric oxide supplements work better than food?

Not reliably. Nitrate from a supplement still depends on tongue bacteria to become nitrite. In a large cohort study, the source of nitrate mattered. Plant nitrate tracked lower death rates, while nitrate from meat and water did not. Food carries the raw material along with everything else in the plant. Keeping the mouth community intact matters as much as the dose. Why muscle loss is a metabolic problem applies the same food-first logic.

What depletes nitric oxide?

Two everyday habits do most of the damage. A daily antiseptic mouthwash kills the tongue bacteria that turn dietary nitrate into nitrite, so the conversion stops. Reheated frying oil adds oxidized fat. Oxidized LDL drives superoxide. Superoxide destroys nitric oxide and uncouples the enzyme your vessel lining uses to make it. Leafy greens, a living mouth community and real olive oil in place of seed oils protect the pathway.

Can you have too much nitric oxide?

Yes, in the wrong place. Your vessel lining makes a steady trickle that keeps small arteries open. An inflammatory enzyme makes a flood. Measured in the rectum, healthy people ran a median 45 ppb. Active inflammatory bowel disease ran 3475 ppb. An inflamed gut can be drowning in nitric oxide while its vessels starve for it. So the goal is a working lining, not a higher reading.

Why do tongue bacteria matter for nitric oxide?

Human cells cannot convert nitrate to nitrite. Bacteria can, mostly in the grooves at the back of the tongue. Your body pumps nitrate from leafy greens back into saliva. There, those bacteria do the conversion. When people rinsed with an antibacterial mouthwash, nitrate in saliva and blood stayed the same. But the conversion to nitrite disappeared. That patch of tongue is a working part of your blood flow.

Sources

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3. Govoni, M., Jansson, E. A., Weitzberg, E., & Lundberg, J. O. (2008). The increase in plasma nitrite after a dietary nitrate load is markedly attenuated by an antibacterial mouthwash. Nitric Oxide, 19(4), 333-337. https://doi.org/10.1016/j.niox.2008.08.003
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Medically reviewed by Dr. Gurpreet Singh Padda, MD, MBA, MHP, board certified in anesthesiology, pain medicine, interventional pain management, addiction medicine and obesity medicine. Adapted from Chapter 9 of The Angry Gut by Dr. Padda and Ami Michelle Grimes. Last reviewed September 2026.