Nitric oxide is a colorless, odorless gas produced by nearly all types of cells in the body. There are many nitric oxide foods that help increase its production in the body to provide a variety of health benefits. Nitric oxide supplements are also available for those who need them.
Nitric Oxide in the Body
According to an October 2015 study published in the Journal of Pharmacological Sciences, nitric oxide affects a variety of cellular processes. It is a free radical that is a potent vasodilator.
The Mayo Clinic says vasodilators are medications that open (dilate) the blood vessels by affecting the muscles in vein and artery walls. Nitric oxide in the body ensures blood can flow more easily through your vessels, keeping the heart from working too hard and bringing down the blood pressure. As such vasodilator medications are used to treat high blood pressure, pulmonary hypertension and heart failure.
Nitric oxide may play a role in psychotic disorders, according to a 2016 meta-analysis of studies published in Current Medicinal Chemistry. The studies only evaluated subjects who were schizophrenic or had a schizoaffective disorder.
The majority were found to have nitric oxide dysfunction in psychosis, thereby strengthening the idea it affects psychotic disorders. The results indicate the need for further research and investigation into a pharmacological intervention in the future.
Nitric Oxide Foods
The wide variety of nitric oxide foods that can be included as part of a healthy and balanced diet ensures you get enough nitrates in your body to produce nitric oxide you need for healthy function.
Beets: Beets are a great source of dietary nitrates, which the body converts to nitric oxide. A December 2015 study published in the International Journal of Food Sciences and Nutrition showed that the amount of nitric oxide in the body increased after drinking 100 milliliters (3.4 ounces) of beet juice.
Dark Chocolate: According to the Harvard T.H. Chan School of Public Health, dark chocolate is a rich source of flavonoids, which the body can convert to nitric oxide.
An April 2018 study in Sports Medicine showed that supplementing with cocoa flavanols may improve vascular function, alter fat and carbohydrate burning during exercise and reduce exercised-induced oxidative stress without affecting exercise performance. However, additional research is necessary to determine the effect of long-term use with exercise training.
Citrus Fruits: When it comes to oranges, grapefruit, lemons and limes, the first thing most of us think about is the vitamin C content. Also known as ascorbate, vitamin C boosts nitric oxide production by enhancing levels of nitric oxide synthase, an enzyme the body needs to make it, as shown in a May 2012 study in Free Radical Biology & Medicine.
Leafy Greens: Leafy greens are full of nitrate, which the body needs to create nitric oxide. According to a March 2017 study published in the African Journal of Traditional, Complementary and Alternative Medicines, greens such as spinach, kale and arugula contain a significant amount of nitrates.
Meat: Meats, including poultry and seafood are high in Coenzyme Q10. Organ meats have a high concentration of the compound. According to a July 2014 study in Molecular Syndromology, CoQ10 appears to lower blood pressure, under the theory that it helps to preserve nitric oxide in the body.
Garlic: Garlic is often used in cooking, and is considered safe when eaten in the amounts found in food. According to the National Center for Complementary and Integrative Health, though there has been a lot of research on garlic, much of it is made of low-quality studies, small scale tests and is still in preliminary stages.
More evidence is needed to definitively prove its nitric oxide boosting ability is helpful to lower blood pressure.
Watermelon: Watermelon is a rich source of citrulline, an amino acid the body converts to arginine before converting to nitric oxide. In a January 2017 study in Current Opinion in Clinical Nutrition & Metabolic Care, watermelon supplementation was shown to reduce resting blood pressure and improve exercise performance.
Nuts and Seeds: Nuts and seeds have a high concentration of the amino acid arginine. A May 2016 study published in Nutrients found that there is a strong association with dietary intake of L-arginine and serum levels of nitric oxide because l-arginine promotes nitric oxide production.
Using Nitric Oxide Supplements
The vasodilating effects may also improve exercise performance by allowing more oxygen and nutrients to get to working muscles during exercise. As a result, many athletes use nitric oxide supplements to boost nitric oxide in the body to improve performance.
According to an April 2017 meta-analysis of multiple studies, published in Sports Medicine revealed that using dietary nitric oxide supplements is likely to provide an increase in endurance exercise capacity but not as likely to be effective when it comes to time-trial performance.
Additional research is required to determine the optimal dosing strategy, the population that is most likely to benefit and the conditions under which dietary nitrates will be the most effective for performance.
Another meta-analysis from June 2018, published in the Journal of Strength & Conditioning Research echoed those same sentiments, also noting that it would be important to consider the type of athlete doing the exercise, the duration and intensity and mode of exercise because these factors are likely to influence the efficacy of nitric oxide supplements.
Once thought to also reduce muscle soreness after exercise, according to a small-scale May 2010 study with 41 participants in the Journal of Strength & Conditioning Research, an October 2017 study published in Nutrients, using citrulline malate, which converts to nitric oxide in the body, did not improve muscle recovery process after an intense workout in untrained young adult males.
According to the U.S. Food and Drug Administration, nitric oxide supplements are generally safe as long as they are taken in the appropriate amounts. Taking larger than recommended doses can lead to diarrhea and stomach upset. Beetroot supplements may cause a harmless change in the color of your urine.
- Journal of Pharmacological Sciences: "Vascular Nitric Oxide: Beyond eNOS"
- Mayo Clinic: "Vasodilators"
- Current Medicinal Chemistry: "Nitric Oxide's Involvement in the Spectrum of Psychotic Disorders"
- International Journal of Food Sciences and Nutrition: "Beetroot Juice Increase Nitric Oxide Metabolites in Both Men and Women Regardless of Body Mass"
- Harvard T.H. Chan School of Public Health: "The Nutrition Source: Dark Chocolate"
- Sports Medicine: "Cocoa Flavanol Supplementation and Exercise: A Systematic Review"
- Free Radical Biology & Medicine: "Ascorbate Stimulates Endothelial Nitric Oxide Synthase Enzyme Activity by Rapid Modulation of its Phosphorylation Status"
- African Journal of Traditional, Complementary and Alternative Medicines: "Nitrate in Leafy Green Vegetable sand Estimated Intake"
- Molecular Syndromology: "Coenzyme Q10 Therapy"
- National Center for Complementary and Integrative Health: "Garlic"
- Current Opinion in Clinical Nutrition & Metabolic Care: "Influence of L-Citrulline and Watermelon Supplementation on Vascular Function and Exercise Performance"
- Nutrients: "The Association of Dietary l-Arginine Intake and Serum Nitric Oxide Metabolites in Adults: A Population-Based Study"
- Sports Medicine: The Effect of Dietary Nitrate Supplementation on Endurance Exercise Performance in Healthy Adults: A Systematic Review and Meta-Analysis"
- Journal of Strength & Conditioning Research: "The Effect of Nitrate Supplementation on Exercise Tolerance and Performance"
- Journal of Strength & Conditioning Research: "Citrulline Malate Enhances Athletic Anaerobic Performance and Relieves Muscle Soreness"
- Nutrients: "Citrulline Malate Does Not Improve Muscle Recovery After Resistance Exercise in Untrained Young Adult Men"
- U.S. Food and Drug Administration: "Title 21: Food and Drugs: Chapter 1 Subchapter B: Food for Human Consumption"