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Nitric Oxide and Diet: Boosting Blood Flow on Low-Carb

How to support cardiovascular health through nitric oxide production

Published January 15, 2025

Key Takeaways

  • Nitric oxide (NO) relaxes blood vessels, lowering blood pressure and improving blood flow [1]
  • Your body makes NO two ways - from nitrates in food (enterosalivary pathway) and from the amino acid L-arginine [2]
  • Arugula is the highest-nitrate vegetable at 2500+ mg/kg, making it ideal for keto [2:1]
  • Mouthwash can raise blood pressure 2-3.5 mmHg by killing NO-producing bacteria [3]
  • Exercise is one of the best NO boosters through shear stress on blood vessels [4]

What Is Nitric Oxide?

Nitric oxide is a gas molecule that your body produces naturally. It plays crucial roles in [1:1]:

  • Blood vessel dilation - relaxing arteries to lower blood pressure
  • Blood flow - delivering oxygen and nutrients throughout the body
  • Exercise performance - improving endurance and muscle pump
  • Immune function - helping fight infections
  • Brain function - supporting memory and cognitive performance

As we age, NO production typically decreases, which is one reason blood pressure tends to rise with age.

How Your Body Makes Nitric Oxide

There are two main pathways [1:2] [2:2]:

1. The Nitrate-Nitrite-NO Pathway

This pathway uses nitrates from food:

  1. You eat nitrate-rich foods (like leafy greens)
  2. Bacteria on your tongue convert nitrates to nitrites
  3. In the acidic stomach, nitrites become nitric oxide
  4. NO enters your bloodstream and tissues

Important: This pathway requires oral bacteria, which is why antibacterial mouthwash can reduce NO production [3:1].

2. The L-Arginine Pathway

This pathway uses the amino acid L-arginine:

  1. L-arginine (from protein foods) enters cells
  2. An enzyme called NOS (nitric oxide synthase) converts it to nitric oxide
  3. NO is released into blood vessels

Both pathways are important for maintaining healthy NO levels.

Low-Carb Foods That Boost Nitric Oxide

Nitrate-Rich Vegetables

These vegetables are high in dietary nitrates that convert to NO [2:3]:

Food Nitrate Content Net Carbs per 100g
Arugula Very High (2500+ mg/kg) 2g
Spinach High (1000+ mg/kg) 1.4g
Celery High (1000+ mg/kg) 1.4g
Lettuce Moderate (500-1000 mg/kg) 1.6g
Bok choy Moderate 1.2g
Radishes Moderate 1.8g

Note on beets: While beetroot is famous for NO boosting, it's higher in carbs (7g net per 100g). A 2022 meta-analysis found beetroot juice reduces systolic blood pressure by about 3.5 mmHg [5]. Small amounts can still fit into keto, or use beetroot powder supplements.

L-Arginine Rich Foods

Food L-Arginine (g per 100g) Net Carbs
Turkey breast 1.7g 0g
Pork 1.5g 0g
Chicken 1.4g 0g
Pumpkin seeds 5.4g 1.3g
Beef 1.2g 0g
Eggs 0.8g 0.6g

Other NO-Supporting Foods

Garlic - Contains allicin which supports NO production and prevents breakdown. Garlic supplements reduce blood pressure by about 10 mmHg systolic in hypertensive patients [6].

Dark chocolate (85%+) - Flavanols increase NO synthase activity. A meta-analysis found optimal endothelial benefits at about 710 mg total flavanols, improving flow-mediated dilation by 1.17% [7]. In hypertensive patients, 15 days of dark chocolate consumption significantly reduced blood pressure and improved endothelial function [8].

Citrus - Vitamin C protects NO from oxidative breakdown by stabilizing tetrahydrobiopterin (BH4), an essential cofactor for NO synthase [9].

The Mouth-NO Connection

One of the most overlooked factors in nitric oxide production is your oral microbiome.

Why Mouthwash Matters

The bacteria on your tongue are essential for converting dietary nitrates to nitrites (step 2 in the nitrate pathway). When you use antibacterial mouthwash [3:2] [10]:

  • Oral nitrite production drops by 90%
  • Plasma nitrite levels decrease by 25%
  • Blood pressure increases by 2-3.5 mmHg

Research shows this effect appears within 1 day of disrupting the oral microflora and persists during continued mouthwash use [3:3].

Protecting Your Oral Microbiome

  • Avoid antibacterial mouthwashes (especially chlorhexidine)
  • Consider probiotic oral care products
  • If you need mouthwash, choose non-antibacterial options
  • Good oral hygiene (brushing, flossing) is still important

Lifestyle Factors for NO Production

Exercise

Physical activity is one of the most powerful NO boosters [4:1]:

  • Shear stress from blood flow stimulates NO production directly
  • Regular exercise increases baseline NO levels and eNOS expression
  • Both cardio and resistance training are beneficial
  • Even walking improves endothelial function

Exercise training has been shown to augment endothelial, NO-dependent vasodilation in both large and small vessels [4:2].

Sunlight

UVA exposure on skin triggers NO release from nitrate stores in the skin. In one study, whole body UVA irradiation decreased blood pressure by 11% at 30 minutes, with increased forearm blood flow (+26%) and improved flow-mediated dilation (+68%) [11]. This may be one reason blood pressure tends to be lower in summer.

Breathing Through Your Nose

Your sinuses produce high concentrations of NO [12], which:

  • Gets inhaled into lungs when you breathe through your nose
  • Improves oxygen uptake
  • Has antimicrobial effects in the airways

Mouth breathing bypasses this benefit entirely.

Managing Stress

Chronic stress and high cortisol impair endothelial function and NO production. Stress management practices like:

  • Meditation
  • Deep breathing
  • Adequate sleep
  • Time in nature

All support healthy NO levels.

Supplements for Nitric Oxide

L-Arginine

  • Directly provides the substrate for NO production
  • Typical dosage: 3-6g per day
  • May cause digestive issues at high doses
  • Short-term supplementation improves flow-mediated dilation [13]

L-Citrulline

  • Converted to L-arginine in the body
  • Often better absorbed than arginine
  • Typical dosage: 3-6g per day
  • A meta-analysis found it reduces systolic BP by about 4 mmHg, especially at doses ≥6g/day [14]

Beetroot Powder/Extract

  • Concentrated source of nitrates
  • Low carb impact (1-2g per serving)
  • A 2013 meta-analysis found beetroot supplementation reduces systolic BP by 4.4 mmHg [15]

Vitamin C

  • Protects NO from oxidation by stabilizing BH4
  • Helps regenerate other antioxidants
  • Typical dosage: 500-1000mg per day [9:1]

Common Questions

Can I boost NO on keto without beets?

Absolutely. Leafy greens like arugula and spinach are actually higher in nitrates per calorie than beets, with minimal carbs [2:4]. Add garlic, dark chocolate, and plenty of protein for a comprehensive NO-boosting approach.

Will nitric oxide supplements help with blood pressure?

They may. Meta-analyses on beetroot juice show blood pressure reductions of 4-5 mmHg systolic [15:1] [5:1]. However, diet, exercise, and lifestyle factors are more important long-term strategies.

Is the nitrate in vegetables the same as in processed meat?

The nitrate molecule is the same, but context matters [16]. Vegetables come with antioxidants (vitamin C, polyphenols) that prevent nitrates from forming harmful nitrosamines. Processed meats lack these protective compounds and are cooked at high temperatures, which can create problematic compounds.

Can too much nitric oxide be harmful?

In practice, it's very difficult to produce too much NO from food or supplements. Your body has regulatory mechanisms. However, if you take blood pressure medications, consult your doctor before adding NO-boosting supplements as the effects may compound.

Putting It All Together

A practical NO-boosting strategy on low-carb:

Daily Habits

  1. Include leafy greens at most meals - arugula, spinach, lettuce
  2. Eat adequate protein - supports L-arginine production
  3. Add garlic to cooking - raw or cooked both help
  4. Enjoy dark chocolate - 1-2 squares of 85%+ daily
  5. Breathe through your nose - especially during exercise

Weekly Habits

  1. Exercise regularly - both cardio and resistance training
  2. Get some sun exposure - 10-20 minutes on skin
  3. Manage stress - whatever works for you

Things to Avoid

  1. Antibacterial mouthwash - kills NO-producing bacteria [3:4]
  2. Smoking - damages endothelial function
  3. Chronic high sugar intake - impairs NO production
  4. Sedentary behavior - reduces shear stress on vessels

The Bottom Line

Nitric oxide is crucial for cardiovascular health, and you can absolutely support NO production on a low-carb diet:

  1. Prioritize leafy greens - they're low carb and high in nitrates [2:5]
  2. Get enough protein - provides L-arginine
  3. Don't use antibacterial mouthwash - protect your oral microbiome [3:5]
  4. Exercise regularly - perhaps the most powerful NO booster [4:3]
  5. Consider targeted supplements if you want extra support

The beauty of focusing on NO is that the same foods and habits that boost it also support overall metabolic and cardiovascular health.

References

  1. 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. PubMed ↩︎ ↩︎ ↩︎

  2. Hord NG, Tang Y, Bryan NS. Food sources of nitrates and nitrites: the physiologic context for potential health benefits. Am J Clin Nutr. 2009;90(1):1-10. PubMed ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎

  3. Kapil V, et al. Physiological role for nitrate-reducing oral bacteria in blood pressure control. Free Radic Biol Med. 2013;55:93-100. PubMed ↩︎ ↩︎ ↩︎ ↩︎ ↩︎ ↩︎

  4. Green DJ, Maiorana A, O'Driscoll G, Taylor R. Effect of exercise training on endothelium-derived nitric oxide function in humans. J Physiol. 2004;561(Pt 1):1-25. PubMed ↩︎ ↩︎ ↩︎ ↩︎

  5. Santana HA, et al. Nitrate Derived From Beetroot Juice Lowers Blood Pressure in Patients With Arterial Hypertension: A Systematic Review and Meta-Analysis. Front Nutr. 2022;9:823039. PubMed ↩︎ ↩︎

  6. Ried K, Frank OR, Stocks NP. Aged garlic extract reduces blood pressure in hypertensives: a dose-response trial. Eur J Clin Nutr. 2013;67(1):64-70. PubMed ↩︎

  7. Joris PJ, et al. Dose-response relationship between cocoa flavanols and human endothelial function: a systematic review and meta-analysis of randomized trials. Food Funct. 2019;10(10):6322-6330. PubMed ↩︎

  8. Grassi D, et al. Blood pressure is reduced and insulin sensitivity increased in glucose-intolerant, hypertensive subjects after 15 days of consuming high-polyphenol dark chocolate. J Nutr. 2008;138(9):1671-1676. PubMed ↩︎

  9. Mortensen A, Lykkesfeldt J. Does vitamin C enhance nitric oxide bioavailability in a tetrahydrobiopterin-dependent manner? Nitric Oxide. 2014;36:51-57. PubMed ↩︎ ↩︎

  10. Bondonno CP, 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. PubMed ↩︎

  11. Oplander C, et al. Whole body UVA irradiation lowers systemic blood pressure by release of nitric oxide from intracutaneous photolabile nitric oxide derivates. Circ Res. 2009;105(10):1031-1040. PubMed ↩︎

  12. Lundberg JO. Nitric oxide and the paranasal sinuses. Anat Rec. 2008;291(11):1479-1484. PubMed ↩︎

  13. Bescós R, Sureda A, Tur JA, Pons A. The effect of nitric-oxide-related supplements on human performance. Sports Med. 2012;42(2):99-117. PubMed ↩︎

  14. Barkhidarian B, et al. Effects of L-citrulline supplementation on blood pressure: A systematic review and meta-analysis. Avicenna J Phytomed. 2019;9(1):10-20. PubMed ↩︎

  15. 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. PubMed ↩︎ ↩︎

  16. Hord NG. Dietary nitrites, nitrates, and cardiovascular disease. Curr Atheroscler Rep. 2011;13(6):484-492. PubMed ↩︎

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