OK, so, let’s start out with what it’s not. It’s not nitrous oxide, the “laughing gas” that dentists used to use to dull the pain of dental procedures. And it’s not sodium nitrite, the preservative added to processed meats like salami and hot dogs, nasty stuff associated with an increased risk of cancer and heart disease.

So, what is nitric oxide? It’s a gas that circulates in suspension in the blood, traveling throughout the body doing good things wherever it reaches. It helps neurons talk to each other and to the muscle cells. It helps fortify the immune system. And perhaps most importantly, it plays a critical role in ensuring that blood flows easily through the blood vessels, bringing oxygen and nutrients to every corner of the body. But as much as nitric oxide helps us, we can help nitric oxide deliver an even greater load of health benefits once we understand how to eat and how to move in ways than increase what our bodies naturally produce. Here’s what you need to know about making friends with your nitric oxide system.

The blood pressure connection.    

Healthy circulation begins with a healthy heart, that amazing muscle that once a second or so powerfully contracts, pumping blood to every part of the body. But just as important as the pump are the pipes, the vessels, that carry that blood. And they couldn’t do it without nitric oxide. It allows the endothelium, thin layer of muscle that lines the vessels, to relax when the heart is pumping, permitting the blood to flow smoothly, and then, when the flow has ebbed, to shrink back to its original shape.

The more nitric oxide is produced, the more supple the vessels, the better able they are to expand and contract without a dangerous increase in blood pressure, that is, the force of the blood pressing against those vessel walls. Inevitably, as we age, the endothelium of the blood vessels grows somewhat stiffer which is why our blood pressure usually increases by the time we hit our middle years. And stiffer vessels, especially the small coronary arteries, are more vulnerable to getting clogged up with cholesterol-filled plaque, further driving up blood pressure and increasing our risk of heart attack. Good diet and plenty of physical activity limit that damage as we age. One important way diet and movement do that is by boosting nitric oxide levels.

Exercising your nitric oxide.

Having a strong pump and flexible pipes allows us to enjoy vigorous physical activity. But exercising the body returns the favor: the more we move around, the bigger the boost for our nitric oxide. When we are in motion, our vessels relax to accommodate our muscles’ greater demand for blood, and then when we gear down, we relax, and our blood pressure drops. Both endurance and strength exercise can serve as a tonic for the cardiovascular system. An added bonus? Exercise stimulates our antioxidant defenses which slow the break-down of nitric oxide so a given amount does more good for longer.

Leafy greens to the rescue.

Leafy greens like arugula, spinach and lettuce are so good for us so many ways, it shouldn’t come as a surprise that they provide the biggest nitric oxide boost in our diet. (If you’re keeping score, arugula is the champ,480 milligrams of nitrates per 100 mg. serving.) Leafys are rich in nitrate compounds which the body converts into nitrites and then into nitric oxide. That’s a little confusing since the nitrates in processed meats are a major health concern. But the veggies’ high antioxidant content (think vitamins C and E and the polyphenols) helps steer the nitrates away from converting into the bad cancer-linked chemicals and towards the heart-healthy ones. And the veggies are also loaded with minerals that support nitric oxide and a healthy circulation.They’ve got ample amounts of potassium, countering the effect of sodium in the diet which, for the salt-sensitive, promotes fluid retention and can push up blood pressure. Leafy greens are also packed with magnesium which plays a number of metabolic roles but, generally speaking, causes muscles, including the musculature inside the vessels, to relax. (It’s easy and cheap to supplement with magnesium: magnesium glycinate also doubles as a mild sleep aid and magnesium citrate, a mild laxative.) All told, a diet rich in leafy greens can approach the blood-pressure-lowering effect of first-line hypertension medications.

Hard to beat beets.

Beets rank up with the veggie leaders in nitrate content and deserve a place at anyone’s health-conscious table. But, because the nitric oxide-boosting power of beets can be readily amplified in the form of beet juice or beet powder supplements, they’ve attracted a fair amount of interest, especially in the sports performance world. The research results aren’t conclusive but some studies have shown increases in muscle power and endurance after a mega-beet dosing. My major caveat though is the sky-high sugar content of beet juice which should put it out of reach for anyone concerned about their glucose readings. For the rest of us, when enjoyed sparingly, the occasional shot of beet juice in a tall glass of seltzer is a simple, nitric oxide-enhancing mocktail for when you need a nitric boost.  

Amino acids to the rescue.

L-arginine is an amino acid found abundantly in protein-rich foods, meat especially, that directly fuels the body’s production of nitric oxide. While most of us get plenty of it in our diets, there is research that supports supplementing with L-arginine for specific purposes, including combating erectile dysfunction and lowering blood pressure in pregnant women. The research suggests that another amino acid, L-citrulline, also made by the body and found not so abundantly in food (watermelon is the stand-out, but also pumpkin and squash), may deliver a boost to healthy circulation. When the body converts L-arginine into nitric oxide, L-citrulline is produced as a byproduct. It’s then recycled back to L-arginine to further pump up nitric oxide production. So, watermelon, either in fruit or juice form, is one nitric-oxide-friendly option, although there’s still the sugar content to reckon with, although not nearly as much as with beet juice, which can be a real sugar bomb. But the L-citrulline supplements mostly sidestep the sugar problem. There’s evidence that supplementation with L-citrulline may be more effective than with the better-known L-arginine when it comes to addressing issues like high blood pressure, exercise performance and erectile dysfunction. While both amino-acid supplements have a reassuring safety profile, it’s best to work with an integrative health care practitioner if you’re interested in integrating them into your health routine – and that’s an especially important must-do for those who are pregnant.

Nitric oxide grab bag.

One nice thing (out of so many!) about nitric oxide is that the body uses so many different metabolic pathways to make it. Consequently, there are a number of different foods that can help this process along. Garlic is one, either fresh or in supplement form, boosting the conversion of L-arginine to nitric oxide. Dark chocolate is another (stick to the lower-sugar, 80% or more, dark cocoa versions and in moderation please), rich in the flavanol micronutrients. Maritime pine bark supplements, often sold as pycnogenol, have a host of micronutrients that look to give nitric oxide a healthful nudge. And finally, here’s something not to put in your body, specifically your mouth, antimicrobial mouthwash that kills off the good bacteria in your mouth which actually begin the conversion of the nitrates you eat into the nitric oxide your body needs.