What is nitrate?
Nitrate (aka inorganic nitrate) is a nitrogen atom bound to three oxygens (NO3), and is related to both nitrite (two oxygens) and nitric oxide (one oxygen). Aside from being naturally occurring in the body, nitrate can be found in many vegetables (leafy green vegetables being the best source, and beetroot being the most famous source). Nitrate is one of two molecules that are said to be the bedrock of the performance enhancing effects of beetroot (the other being betaine).
How is nitrate related to nitric oxide?
Nitrate can be converted to nitrite in the body, and then nitrite can readily degrade into nitric oxide. Unlike the conversion of l-arginine into nitric oxide (which requires the enzyme nitric oxide synthase), nitrite is not localized to this enzyme. Your body can produce nitric oxide from nitrite in a variety of ways, and nitrite seems to be a regulator of microcirculation (the smaller blood vessels in your body, which are highly associated with “the pump”).
In a sense, dietary nitrate is an alternate source of nitric oxide that works differently than L-arginine (but with better results).
How does nitrate benefit exercise?
Studies conducted on nitrate (either via beetroot or via sodium nitrate) suggest that nitrate is able to delay exhaustion and increase average power output in intensive exercise that lasts over a minute and is more muscular in nature (crossfit, rugby, or rowing as examples). It appears to have also benefit exercises that are even longer, but not nearly as much.
Nitrate does not appear to enhance power output (unlikely to benefit powerlifters), although it might increase power output in exercise that is extended such as a short race.
It is thought that this is due to increasing mitochondrial efficiency, and allowing more ATP (cellular energy) to be made per molecule of glucose or fatty acid. This is a benefit of nitric oxide itself, and anything that can increase nitric oxide capacity in the body basically gives you more energy.
Are there any health related effects of supplemental nitrate?
Nitrate appears to reduce blood pressure in people with high blood pressure. It also reduces blood pressure in healthy people when they exercise (which inherently causes blood pressure to rise), but does not decrease pressure when a healthy person is at rest. Due to this, intake of nitrate is unlikely to induce low blood pressure (hypotension) to problematic levels.
The ability of nitrate to favour microcirculation could be useful for people with metabolic syndrome or diabetes, where microcirculation is decreased and diabetic neuropathy is a risk.
It is thought that nitrate could reduce the rate of cognitive aging (via preserving blood flow to the brain), but this hypothesis is not yet tested.
What are common sources of nitrate?
The most popular source of dietary nitrate is beetroot, and beetroot appears to be the best source of nitrate when looking at tuber vegetables. The entire tuber vegetable class (beets, radishes, turnips) seem to have high nitrate values, outperformed only by leafy vegetables (lettuce, spinach, rocket, celery, Chinese cabbage) which are the highest sources.
Nitrate is found in most foods, although in low enough levels that they might not exert benefit to the body. Beyond the vegetables already mentioned, the other dietary source that may contribute to nitrate in the diet is processed meats (as sodium nitrate is a preservative in pink meats, and confers dietary nitrate).
Nitrate is a highly promising nutritional supplement that may be the link between health and leafy green vegetables. Currently, nitrate appears to have more ergogenic potential than beta-alanine at the same game and can confer a wide range of cardiovascular and blood flow health effects.
About the Authors
Kurtis Frank and Sol Orwell are the co-founders of Examine.com. Examine.com is a database on supplementation and nutrition, helping you figure out what works (and what doesn’t). They are currently working on a beginner’s guide to supplementation.