Nitric Oxide (NO) as an Important Helper in the Body

Nitric oxide is generally better known as a problematic environmental pollutant from motor vehicle and industrial exhaust emissions. It is an aggressive gas that, at high concentrations, damages the airways and prevents oxygen transport in the body. But nitric oxide also has another side that is extremely important and useful to us.

High blood pressure, among other things, damages the innermost layer of the blood vessels-the endothelium. The endothelium has important tasks in regulating blood pressure because it influences vessel tone. That means it helps determine whether a vessel is constricted and less elastic or relaxed and elastic. The endothelium contributes to this process through one of its functions: it helps produce the body's own nitric oxide (NO).

Besides its relaxing, so-called vasodilatory effect on the blood vessels, NO has other important roles in the body. For example, it inhibits platelet aggregation, so it prevents blood platelets from clumping together and forming clots. On the surface of the endothelium, it reduces the formation of certain molecules that allow white blood cells (leukocytes) to adhere, which represents the first stage of atherosclerosis. NO also reduces the formation of free radicals and the oxidation of fats, which both contribute to atherosclerosis. In addition, it has an anti-inflammatory effect in the body.

For the blood vessels this is beneficial in several ways: it relaxes and widens the vessels, counteracts the development of atherosclerosis that narrows the vessel, and has anti-inflammatory effects. Inflammation would, in turn, mean narrowing of the vessel. It also reduces the formation of blood clots that could get stuck in narrow spots and cause a blockage.

Where does the useful NO in the body come from?

The body produces NO in the endothelial cells that line the inside of the blood vessels. For this it needs an enzyme called NO synthase, which combines the nitrogen-containing amino acid arginine with oxygen. The arginine molecule then releases NO; the remainder of the molecule is further processed. The "raw material" arginine is also produced by the body at least when we're younger.

However, the body's immune cells-the macrophages-are also able to produce NO to fight bacteria.

Increased amounts of NO are produced endogenously in the paranasal sinuses and then taken up through the inhaled air, particularly when breathing through the nose. This reduces vascular resistance in the lungs and improves oxygen uptake. There is evidence suggesting that increased NO production in the paranasal sinuses is a defense mechanism used by the body against bacteria and viruses.

Unfortunately, the body's NO production decreases with age. This is partly due to reduced arginine production in the body. Arginine can, however, be supplied relatively easily through food. Sunflower seeds, nuts and legumes are, for example, good sources of arginine. The endothelium itself also ages and loses some of its functional capacity.
A study published in 2025 showed that older people responded better than younger ones to drinking nitrate-rich beetroot juice; the blood pressure of these participants fell. This is attributed to changes in the oral flora caused by the juice. Those changes were also found in younger study participants, but they did not lead to lower blood pressure in that group, possibly because their blood pressure was already in the normal range.

NO precursors, such as inorganic nitrate, can also be taken in with food. In the body, these are first converted to nitrite, from which the body can then produce NO in further steps. A good source of these precursors that has also been studied for its positive effect on blood pressure is beetroot - especially beetroot juice. Other vegetables (particularly green leafy vegetables) also contain these important substances.

The following image shows how this conversion takes place in the body:

Because the converted NO is ultimately available again in the salivary glands, it can be inhaled with each breath. Studies showed that after drinking 500 ml of beetroot juice, the nitric oxide level in the exhaled air of COPD patients was more than 200 percent higher than before drinking the beverage.

Organic beetroot juice Rübenherz

Concentrated organic beetroot juice is available from the Austrian organic fruit juice producer fitrabbit. The nitrate content is about five times that of standard commercially available beetroot juice. The producer recommends 100 ml per day, which is equivalent to half a litre of standard commercially available juice. In the convenient 3-litre box, it keeps for months without refrigeration.
Recognised as a Top Innovation 2015 at Anuga, the world's leading food and nutrition trade fair.
With the voucher codeBLUT120, you receive a €7 discount. Go to the shop.

Notes: Please check any applicable voucher terms and conditions. We receive a commission on orders.

Sources:

This article is from Tensana – the leading app since 2011, helping hundreds of thousands of people monitor their blood pressure every day. Our content is based on carefully researched, evidence-based data and is continuously updated (as of 02/2026).

Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as outpatient care, and has headed the specialist editorial team at Tensana since 2015. Thanks to her extensive additional qualifications as an emergency medical technician, first responder, and in various areas of therapy and emergency care, she provides well-founded, practical, and reliably verified information.

Nitric Oxide (NO) as an Important Helper in the Body

Where does the useful NO in the body come from?

Organic beetroot juice Rübenherz

Sources:

Registry: