In Experiment 001, Sun Powered, I wrote that nitric oxide does an enormous amount of work in your body, and that I would come back to it. This is me coming back.
Nitric oxide is a gas: one atom of nitrogen, one of oxygen. Its main job is to tell your blood vessels to relax and open. Wider vessels mean lower blood pressure and more blood and oxygen reaching your muscles, your brain and everything else.
Your body makes it two ways. The first is built in. The cells lining your blood vessels make it on their own, and they make more every time blood rushes past them, which is a big part of why exercise works. The second runs through your food and your mouth, and it is the one you can feed directly.
An explosive story.
Alfred Nobel made his fortune from dynamite, which is built on nitroglycerin. Late in his life, sick with heart disease, his doctor prescribed him nitroglycerin. He wrote: "It is ironical that I am now ordered by my physician to eat nitroglycerin."
It took a hundred years to find out why it helped. Nitroglycerin releases nitric oxide. In 1998 three American scientists, Robert Furchgott, Louis Ignarro and Ferid Murad, won the Nobel Prize, the prize Nobel's own fortune pays for, for showing that nitric oxide is a signal in the heart and blood vessels. That same year, the FDA approved Viagra, which works by keeping the nitric oxide signal switched on longer.
Beets and greens.
Beets, arugula, spinach and other leafy greens are full of nitrate. Nitrate needs help. Bacteria living on your tongue turn it into nitrite. You swallow that, and your body turns it into nitric oxide. No bacteria, no nitric oxide from your food.
Arugula carries the most nitrate by weight: German food safety testing found about 4,700 milligrams per kilo, more than beets. But you would need a big bowl of it. Beets are the easy way to a real dose, which is why most of the research uses beet juice. I eat a lot of beets. Nitrate dissolves in water. When you boil them, part of it ends up in the red cooking water, so I always drink it.
The evidence for beets is some of the best in nutrition. In a 2015 trial, people with high blood pressure who drank 250 milliliters of beet juice a day for four weeks lowered their blood pressure by about 8 points, and their arteries became more flexible. At the University of Exeter in 2009, cyclists who drank beet juice for six days lasted 16 percent longer before exhaustion. Peter Attia notes that an international sports medicine consensus lists nitrate among the few supplements with strong evidence. The effect is real. Nathan Bryan, a nitric oxide researcher, believes in beets so much that he wrote a whole book about them and called it Beet the Odds.
Protect the bacteria.
Strong antiseptic mouthwash wipes out the good bacteria with the bad. It does not pick sides. In a 2013 study in London, a week of it cut the nitrite coming from people's mouths by about 90 percent, and their blood pressure went up. In a study in San Juan, Puerto Rico, adults who used mouthwash twice a day or more had a 55 percent higher risk of developing prediabetes or diabetes over three years. That study shows a link, not proof, but the pathway behind it is real.
I stopped using mouthwash a few years ago, and started using a tongue scraper around the same time. A scraper cleans your tongue without wiping out the good bacteria you need. A small 2019 study found that people who cleaned their tongue every day carried more of the nitrate-turning bacteria, not fewer. Tongue scrapers have other benefits too, and I will write about them soon.
The rest of the list.
1. Breathe through your nose.
Your sinuses make nitric oxide all day, in very high concentrations. Breathe through your nose and every breath carries it down into your lungs, where it opens the vessels that pick up oxygen. Breathe through your mouth and you skip it. Plenty of people who breathe through their nose all day breathe through their mouth at night, and miss it for hours. I wrote about mouth taping in Experiment 002, Take a Breath.
2. Hum.
In that Experiment, I also wrote that humming raises nasal nitric oxide about 15 fold, and I promised to explain the vibration. Humming makes the air in your nose shake, and that pumps air in and out of your sinuses, where the nitric oxide is made. Quiet breathing barely moves the air in there at all.
3. Practice your breathing.
A few minutes of slow breathing through the nose each day trains you to breathe that way without thinking, and every one of those breaths carries nitric oxide down with it. Experiment 002, Take a Breath walks through the practices.
4. Get sun on your skin.
Your skin holds its own store of nitric oxide. The UVA in sunlight releases it straight into your blood, with no eating, digesting or converting. I wrote more about it in Experiment 001, Sun Powered.
5. Sweat.
In Finland, one 30 minute sauna session lowered people's blood pressure from 137 over 82 to 130 over 75, and their arteries were less stiff afterward. I never skip the chance for a sauna session. Sauna has many other benefits, which I will cover in the Experiment on heat and cold.
6. Train hard.
This is the built-in route. When your heart pumps harder, blood rushes along your vessel walls, and the cells lining them answer by making more nitric oxide. Regular exercise is the main thing shown to protect that system as you age. My go-to is high intensity interval training, which is known to switch on nitric oxide. A review of seven trials found that interval training improved how well arteries widen about twice as much as steady cardio did.
7. Eat the other helpers.
A review of 42 trials found that cocoa flavanols, the compounds in dark chocolate, helped arteries widen and lowered blood pressure. In a review of 20 trials, garlic lowered blood pressure by about 9 points in people with high blood pressure. Across 14 trials, pomegranate juice lowered it by about 5. I always have fresh garlic in my pantry, a big collection of dark chocolate, and pomegranate molasses, which I wrote about in Experiment 006, Well Preserved.
8. Citrulline and arginine.
Arginine is the raw material your vessels use to make nitric oxide, and citrulline is an amino acid your body turns into arginine. Watermelon is the richest food source of citrulline, and pumpkin seeds are among the richest in arginine. Get them from food, and skip arginine pills: your body breaks most of them down before they reach your blood.
A bonus for men.
An erection is a blood flow event, and it runs on nitric oxide. That is how Viagra works. Every habit in this Lab Note raises nitric oxide, so they all feed the same system.
Here is what you can do this week. Skip the antiseptic mouthwash, unless your dentist prescribed it, and start using a tongue scraper. Eat a beet or a big bowl of arugula every day. Breathe through your nose, day and night. Get some sun, without burning. Get your heart rate up. Your body already knows how to make this molecule. Feed it, and get out of its way.
Georges
Usually one Experiment on Sunday. Lab Notes in between. Free.
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