When we hear “nitrates,” we often think of the problematic preservatives lurking in processed meats. Yet these are only one piece of a nutrient jigsaw puzzle; the full picture is much more interesting.
Naturally occurring nitrates and nitrites found in vegetables, fruits, and drinking water are the focus of promising new longevity research — primarily because of their role in producing nitric oxide.
Nitric oxide is a beneficial gas formed by the cells of the endothelium. It plays a substantial role in how gracefully our bodies age — or don’t. The body can make nitric oxide, but it relies more on dietary nitrates to do so as we age. Without these compounds in our diets, our health can wither.
Nitric oxide is an unstable gas, so its presence in the body is fleeting — diffusing in less than a second. Yet it adds life to almost everything it touches. It acts as a signaling molecule in the brain and nervous system, regulates insulin, guards against pathogens, and unglues blood platelets, making them less likely to clump together into dangerous clots. It’s so important to health that a Nobel Prize was awarded in 1998 to scientists who first identified nitric oxide’s role as a signaling molecule.
“Nitric oxide is a molecule at the very fulcrum of our well-being.”
Most important, nitric oxide is a vasodilator, meaning it enables the body’s 60,000 miles of blood vessels to open and relax. When nitric oxide is present, blood flows more freely.
“What could be more important than increasing blood supply to every organ, including the brain?” asks board-certified neurologist David Perlmutter, MD, FACN.
“Nitric oxide is a molecule at the very fulcrum of our well-being.”
All the more reason to overcome our fear of nitrates — and to include more nitrate-rich foods in our diet.
Nitric Oxide and Age-Related Declines
The body makes nitric oxide in two ways. Cells lining the blood vessels produce nitric oxide from L-arginine, an amino acid found in meat and nuts. This process declines with age, but the body also makes nitric oxide by processing nitrates directly from food.
Nitrates are found in dark, leafy greens and certain root vegetables, like beets. Understanding their importance requires a quick hit of chemistry.
A nitrate is made up of a nitrogen atom bonded to three oxygen atoms (NO3). A nitrite is a nitrogen atom bonded to just two oxygen atoms (NO2). Both are essential to the body’s production of nitric oxide from food. Eating nitrate-rich foods kick-starts a process in which the body converts nitrates to nitrites and, eventually, nitric oxide.
As the L-arginine pathway declines with age, nitrates in the diet can pick up the slack — if we’re eating enough of them.
“Without nitric oxide, every function in the body works less efficiently.”
“By the time we reach 40, we have lost roughly 50 percent of our [endothelial] nitric oxide production,” says Nathan Bryan, PhD, coauthor of The Nitric Oxide (NO) Solution. “Without nitric oxide, every function in the body works less efficiently.”
Blood pressure is a case in point. As blood circulates, it presses against vessel walls. In younger bodies, arteries and blood vessels are usually more supple, expanding and contracting with each heartbeat. As arteries stiffen with age, pressure against their walls climbs to keep blood flowing. When blood pressure rises and stays up, it’s called hypertension.
Nearly half of Americans over age 20 have hypertension. It’s a risk factor for heart disease and stroke, two of the leading causes of death in the United States. Type 2 diabetes, vascular dementia, and chronic kidney disease can also be triggered or exacerbated by hypertension.
“The epidemic of hypertension in our culture has a strong correlation to a deficiency of nitric oxide,” says functional-medicine practitioner Christopher Bump, DC. He attributes that deficiency, in part, to weak digestion.
“I don’t know why more people aren’t talking about nitric oxide as a means of increasing blood flow,” says integrative physician Frank Lipman, MD.
“It’s very important and yet underreported.”
Nitrate Sources
In 2022, the journal Environment International published a panoptic view of the link between nitrates and hypertension. Analyzing more than 55,000 subjects from the famous observational Nurses’ Health Study, scientists looked at the relationship between the nurses’ risk of high blood pressure and how many nitrate-rich foods they ate.
Results showed that for each 150 mg hike in dietary nitrates, the nurses’ risk of hypertension dropped proportionally.
In a much smaller study, healthy, young participants consumed an average of two servings of high-nitrate vegetables daily for one week. Nitrates in their plasma increased by approximately 250 percent and their blood pressure lowered significantly.
All in all, vegetables and fruit account for approximately 80 percent of the nitrates in the average person’s diet. Groundwater contains nitrates, so drinking water is our second-largest source. Finally, meat makes up roughly 6 percent for nonvegetarians.
Increasing nitric oxide can be as easy as adding more beets and arugula to your plate.
Food manufacturers add nitrates and nitrites to processed meats to slow bacterial growth, impart flavor, and enhance color. The dangers with these compounds arise during cooking and digestion, when added nitrates and nitrites can transform into nitrosamines, which are carcinogenic. Studies link nitrosamines to a heightened risk of colorectal cancer. (Many organic cured meats are preserved with nitrites derived from celery nitrates, thought to be a safer alternative to synthetic nitrites, though the research is mixed on this point.)
Nitrates in vegetables don’t pose the same risk. Vegetables high in nitrates — such as arugula, spinach, and beets — contain a bounty of antioxidants that offset potential harm. Fruits such as watermelons and bananas also contain trace amounts of nitrates that contribute to your total intake.
“The presence of antioxidants inhibits the generation of troubling nitrosamines,” explains Kathie Swift, MS, RDN, LDN, cofounder of the Integrative and Functional Nutrition Academy. “So, veggie up, and fill your plate with reds, like beets, and greens, such as spinach, arugula, lettuce, chard, and celery.”
The Ideal Amount
There is no recommended dietary allowance for nitrates, but Bryan suggests aiming to eat roughly 300 mg a day. The typical American diet contains about 150 mg.
It bears repeating that nitrates are most plentiful in arugula (also called rocket), beets, Swiss chard, celery, lettuce, and spinach. Arugula tops the list with 480 mg of nitrates per 100-gram serving (try some of these recipes that feature arugula). Other good sources include Chinese cabbage, endive, fennel, leeks, and parsley.
Though supplements are a tempting shortcut, nitrates from whole-food sources are a safer choice. Produce packages nitrates alongside antioxidants, vitamins, minerals, and trace elements, while supplements make it easy to get too much.
“It’s all a matter of concentration,” says Bump. “In lower concentrations nitric oxide has many positive effects, but in higher concentrations it becomes the evil empire. It becomes a free radical leading to increased oxidative damage that can interfere with health.”
For a 2023 study published in the journal Foods, researchers examined 50 beetroot supplements. Most products did not deliver the number of nitrates touted on the label. At the same time, the quantity of other antioxidants was too low to balance nitrates’ propensity for free-radical production.
Those who find the siren song of supplementation irresistible may want to consider beet juice. The authors of a 2017 meta-analysis of 43 trials found the juice had a significant beneficial effect on blood pressure, especially in trials that lasted more than two weeks.
Still, Lipman cautions anyone watching their glucose to be moderate with beet juice, which contains a substantial amount of natural sugar.
Made to Measure
Because nitric oxide is an unstable gas that dissipates quickly, it’s nearly impossible to measure. But that hasn’t kept people from trying, at least indirectly.
The nitric oxide saliva-test strips available online claim to measure whether the body has the raw materials necessary to make nitric oxide. But the strips don’t hold up to scientific scrutiny.
Authors of an exhaustive study, published in 2015 in the journal Nitric Oxide, wrote that the test strips did show a relative level of nitrites in subjects’ saliva, but they are “not likely to accurately assess nitric oxide bioavailability.”
A more useful approach may be certain blood tests. Asymmetric dimethylarginine (ADMA) interferes with L-arginine, the amino acid the body needs to make nitric oxide. High blood levels of ADMA are a sign of endothelial dysfunction.
“When that marker is high,” says Lipman, “it’s an indication that someone needs more nitric oxide.”
To boost nitric oxide levels, Lipman sometimes recommends supplements that include L-arginine and L-citrulline, a byproduct the body makes when it converts L-arginine into nitric oxide.
One sign of flagging nitric oxide levels can be sexual dysfunction. The body employs nitric oxide to relax blood vessels, allowing a surge of blood to reach the sex organs during arousal. Difficulty achieving arousal and erection is even considered an early warning sign for heart disease.
Sexual dysfunction and hypertension are so closely linked that the drug Viagra was discovered by scientists who were developing a drug for hypertension and angina chest pain caused by constricting blood vessels. The drug makes vessels more sensitive to nitric oxide, and the resolution of erectile dysfunction was an unexpected side effect.
Lipman even prescribes daily low-dose Viagra off-label to offset the nitric oxide depletion that comes with aging. He says low-dose Viagra has practically become standard practice in antiaging circles. He takes it himself and recommends it to male and female patients alike.
“I’m obsessed with what happens to our bodies as we get older,” Lipman says. “Most of us aren’t paying enough attention to nitric oxide, but we really should.”
Meanwhile, increasing nitric oxide can be as easy as adding more beets and arugula to your plate. If only everything that offsets the effects of aging could be that easy.
5 More Ways to Boost Nitric Oxide
Nitric oxide is a gas that can’t be harnessed well in a supplement, so nitrate-rich foods are your best source. There are also nondietary ways to increase the body’s production, including the following.
1) Exercise 20 to 30 minutes daily. It may seem obvious that exercise lowers blood pressure. What’s new is that scientists now know exercise triggers endothelial cells to release nitric oxide. “It is one of the most powerful ways to increase how much nitric oxide your body makes,” says board-certified neurologist David Perlmutter, MD, FACN.
And, he notes, the downstream effects of more nitric oxide are “good for the brain, good for the immune system.”
2) Wean off the antacids. Antacids and acid suppressors, like proton pump inhibitors, seem like an easy fix for a sour stomach, but the body needs stomach acid to make nitric oxide from food and exercise. Regular use of proton pump inhibitors has been linked to an increased risk of heart attack, stroke, and dementia. (Here’s more on how chronic use of this common over-the-counter medication can become problematic.)
“Turns out that shutting down stomach-acid production is a really bad idea,” notes Nathan Bryan, PhD. “Our entire digestive, endocrine, and cardiovascular system depends on our ability to produce stomach acid.”
3) Buy local produce but not necessarily organic. In what may seem counterintuitive, a 2015 study found conventionally grown vegetables have substantially more nitrates than the same vegetables grown organically. Bryan suspects it’s because U.S. organic growers are not allowed to use synthetic nitrogen-based fertilizers.
“Without nitrogen, vegetables can’t assimilate nitrates,” he says. “Your best bet is to buy local, conventionally grown vegetables.” (At least sometimes: Most organic growing practices are still better for the soil and overall biodiversity.)
4) Practice deep breathing. Oxygen is essential to the body’s production of nitric oxide. “Breathing deeply stimulates receptors in the body that turn on nitric oxide production,” says Bryan. “Taking in that life-giving oxygen will help support every biological function in the body.”
He advises taking 10 deep breaths, inhaling through the nose and exhaling through the mouth, at least three times a day.
5) Eat nitric oxide–adjacent nutrients: Nudge up nitric oxide production by giving your body ample potassium and magnesium, says integrative physician Frank Lipman, MD. Potassium helps balance dietary sodium, which on its own can drive up blood pressure.
And magnesium prompts muscles and the endothelium to relax. As a bonus, magnesium glycinate is a mild sleep aid. “Magnesium is easy and cheap,” he says. “I recommend it to everyone.” (Explore these tips to increase your magnesium intake.)
The Trouble With Mouthwash
Swishing mouthwash may seem like a bedrock of good oral healthcare, and studies do show that it — along with brushing and flossing — can lower the risk of gum disease. But nitric oxide experts say the cost is way too high.
“Mouthwash does a good job at killing bad breath,” says Nathan Bryan, PhD, coauthor of The Nitric Oxide (NO) Solution, “but it also kills the bacteria essential to nitric oxide production.”
Mouthwash does to the oral microbiome what antibiotics do to bacteria in the gut — annihilates good and bad guys alike.
The mouth is home to more than 700 species of bacteria. Mouthwash does to the oral microbiome what antibiotics do to bacteria in the gut — annihilates good and bad guys alike. Decimating the oral microbiome every day (or sometimes twice a day) can have negative repercussions for systemic health.
Bryan draws a direct line from the estimated 200 million Americans who use mouthwash daily to the 122 million Americans with high blood pressure.
When scientists followed 540 higher-weight adults in San Juan, Puerto Rico, for three years, they found that those who used mouthwash twice daily were 85 percent more likely to develop hypertension than their peers who used mouthwash less frequently.
“The No. 1 thing a person can do to protect their levels of nitric oxide is to stop using mouthwash,” Bryan says.
This article originally appeared as “Nitrates Are Not What You Think” in the November/December 2024 issue of Experience Life.
