Blood flow is crucial for any of the functions of the body to work properly. Without healthy blood flow people can begin to experience many different problems form low energy, cold fingers and toes, muscle loss, and more. In this guide we will discuss what nitric oxide is, how it contributes to improving your blood flow & circulation, and why you may want to start consuming more nitric oxide boosting foods.
Let's dive in!
Table of Contents:
- What Is Blood
- The Circulatory System
- Vasodilation vs Vasoconstriction
- Nitric Oxide Vs Nitrous Oxide
- Food That Increase Nitric Oxide Production
- Foods That Increase Vasoconstriction
What Is Blood
Before we go into blood flow let’s briefly talk about the composition of blood, its function in the body, and how it's made. Blood is our body’s primary method of bulk flow, allowing us to transport oxygen, carbon dioxide, nutrients and waste throughout the body. Blood consists of three main components:
Plasma~ 55% of blood
- Plasma is the fluid part of blood in which all the other parts are suspended in. It is mostly made up of water, but also contains a portion of electrolytes, proteins (mostly albumin) among other nutrients. Plasma is also responsible for the long-distance transportation of hormones throughout the body
Red Blood Cells (erythrocytes) ~ 45% of blood
- Red blood cells are the “functional unit” of our blood. They are responsible for the transportation of oxygen to our bodily tissues and the removal of carbon dioxide. Red blood cells are able to do this through the protein known as hemoglobin. Hemoglobin is made up of four parts. Each is capable of binding to one molecule of oxygen or carbon dioxide. Each subunit of hemoglobin is able to change its shape or conformation to either pick up oxygen and release carbon dioxide or release oxygen and pick up carbon dioxide. This depends on the local concentration of oxygen and carbon dioxide. This is known as the Bohr effect.
White Blood Cells (leukocytes) ~ >1% of blood
- White blood cells comprise mostly the “immunity” portion of our blood. There are five main types of white blood cells. Each of them has a different function pertaining to our immune system. Leukocytes are responsible for defending our body from foreign or toxic substances, known as antigens. These can consist of viral, bacterial, fungal infections, parasites, allergens and at times cancer. They are also responsible for creating proteins known as antibodies to fight specific antigens.
- Antigens - Any substance that warrants an immune response from the body.
- Antibody - A protein that is designed to counteract a specific antigen.
Platelets (thrombocytes) ~ 1% of blood
- Platelets serve as the “healing” portion of our blood. When bleeding occurs the platelets gather over the tear in the blood vessel. They cover it in order to allow for the blood to clot and bleeding to cease.
All red blood cells and the majority of white blood cells/platelets are created through a process called hematopoiesis in which stem cells from bone marrow are converted into their designated forms. Red blood cells have a lifespan of about 120 days. Our body is constantly creating new blood cells to maintain the amount of red blood cells in circulation.
The Circulatory System:
Now that we have some understanding of what comprises our blood, we must also have a general understanding of how our circulatory system transports blood. In my opinion, the easiest way to view our circulatory system is to imagine it as your local mail system. It all starts in the post office, which packages up and distributes the town’s mail.
This mail is then divided up amongst the mailmen and placed into their respective mail trucks. The mailmen carry out their delivery routes, traveling on the main roads to get to the backroads of town. And finally dropping off any incoming mail and picking up any outgoing mail.
In this model, our heart and lungs function as the local post office. They prepare our blood to be distributed throughout the body. Our arteries/veins serve as big big roads, our capillaries serve as residential roads, and the mail represents our blood.
In actuality our circulatory system really starts with our breath. When you breathe air in, you take in a mixture of oxygen, nitrogen and a number of trace gases. This oxygen-rich air flows down into your lungs where an exchange of gases occurs.
Oxygen-poor blood is transported from the heart via the pulmonary arteries into the lungs. At this point, the oxygen-rich air begins to diffuse into the red blood cells and carbon dioxide begins to flow out of the red blood cells into the lungs. The pulmonary vein transports the oxygen-rich blood back into the heart. From there the blood will be pumped out through the rest of the body.
Blood is transported throughout the body via a series of arteries that become progressively smaller. The further they are from the heart the smaller they get due to less blood being present. (Think highways -> main roads -> back roads). As the blood reaches its target tissues the arteries will branch out into thousands of tiny capillaries. This is where gas and nutrient exchange will occur again.
These capillaries will connect to veins which are responsible for transporting the oxygen-poor blood back to the heart. The oxygen-poor blood will release carbon dioxide into the lungs. Then we will expel the carbon dioxide as we breathe out and start the cycle anew.
Naturally, our body always wants to remain in homeostasis or in balance with its environment. Due to our ever-complicated lives this is not always possible. So in order to regulate itself, our circulatory system contains a number of mechanisms that it uses to regulate blood flow throughout the body.
For example, we have all experienced an increase in heart rate while exercising. This occurs in order to meet the body's increased demand for oxygen, as we expend more energy. As our heart rate increases our blood pressure will follow suit. This allows for the heart to a larger quantity of blood per beat. Over time, when we stop exercising our body will slowly bring our heart rate and blood pressure back to its normal level.
Our body is also able to proportion and distribute blood to areas that have a higher demand for oxygen. At rest, our body will naturally prioritize more blood flow to our organs. While we are active more blood will be sent to our muscles. As seen in the image below, only 15-20% of blood is proportioned to our muscles at rest, while up to 85% can be found in our muscles during strenuous activity.
Our body is able to accomplish this via strategic narrowing and widening of arteries throughout the body by regulating its vascular tone. Every artery in the body is encased by a thin layer of muscle which is able to contract or expand.
When contracted this results in a smaller opening for blood to flow through, resulting in less blood flow. When relaxed, the dilated artery allows for more blood to pass through at a lower blood pressure. The process of arterial tightening and widening is known as vasoconstriction and vasodilation respectively.
Vasoconstriction occurs in order to restrict blood flow by tightening our blood vessels. The body can utilize vasoconstriction in order to conserve body heat or re-direct blood flow to another area. This results through a narrowing of the arteries and an increase in blood pressure because of the decreased diameter of the arteries.
While vasoconstriction has its time and place, many people today can get stuck in a degree of constant vasoconstriction due to various lifestyle and nutritional stressors. This can lead to high blood pressure (hypertension) among other health issues over time.
Vasodilation occurs in order to increase blood flow and thereby increase nutrient and oxygen delivery and waste removal throughout the body through the widening of our blood vessels. This will result in lower blood pressure and improved circulation.
Additionally, vasodilation allows for more heat to be released into the environment during periods of heavy exercise to help maintain a constant body temperature. The body’s main mechanism for signaling vasodilation is through the molecule nitric oxide.
Nitric Oxide Vs. Nitrous Oxide:
Nitric Oxide is a gas that is made up of one nitrogen atom and one oxygen atom. Like most gases, nitric oxide is very unstable in the body and only lasts for a few seconds until it is broken down. Before it is broken down nitric oxide serves as a signaling molecule in the body and produces a vasodilatory effect.
As we know, vasodilation is the process in which our arteries “dilate” or expand, allowing for more blood to flow through the arteries at a lower blood pressure increasing oxygen and nutrient delivery and waste removal. Not to be confused with its sister molecule, Nitrous Oxide...
Nitrous Oxide is also a gas, consisting of two nitrogen atoms and one oxygen atom. Nitrous oxide is not produced in the body and is most commonly known for its anesthetic properties and ability to increase engine power. You may have heard of it referred to as laughing gas or nitrous/NOS. Despite nitric oxide and nitrous oxide having very different properties in the body they actually function in a very similar manner.
To see these similarities let’s take a look at how nitrous oxide works in a car engine. When nitrous oxide is released into the engine, it is immediately heated up, causing the molecule to break apart into separate atoms (two nitrogen atoms and an oxygen atom). This increases the relative amount of oxygen that is in the system, allowing for more combustion (burning of fuel) and resulting in more engine power.
More Oxygen = More “Fuel” = More Power
The extra nitrogen in the system also has a cooling property, allowing the engine to remain at a relatively constant temperature, despite the increased rate of combustion.
Nitric oxide is produced when the nitric oxide synthase enzyme converts the amino acid L-arginine into the amino acid L-citrulline and nitric oxide as products. In this process the cofactors: NADPH, O2, BH4, FMN, FAD are used in addition to the nitric oxide synthase enzyme in order to help catalyze (start/process) this reaction. Logically, if our goal is to boost our nitric oxide levels there a few pathways by which we can do so:
- Increase our supply of L-arginine & L-Citrulline
- Boost nitric oxide synthase activity
- Maximize the stability of nitric oxide
- Increase our supply of involved cofactors
Before we delve into foods that increase nitric oxide production, I’d like to briefly address the concept of supply & demand and the law of diminishing returns relating to biology. When looking to increase the production/occurrence of any biological process, we need to find the limiting factor of the reaction.
The limiting factor in our context is the molecule in the reaction that is lacking in supply thus limiting the amount of times that the reaction can occur or in our case the amount of nitric oxide produced.
For example, if you are deficient in l-arginine, by consuming more l-arginine you will increase the amount of nitric oxide production that is able to occur. L-arginine in this case is our limiting factor. It should also be noted that there can be multiple limiting factors. In economic terms, when supply = demand we reach equilibrium. In biology this translates to a balance in the reaction(s), meaning we are using the reactants or cofactors just as fast as we are replacing them. Increasing the quantity of any of these substances before the equilibrium point will almost always result in increased production.
But increasing the quantity of these substances after the equilibrium point may or may not increase the amount of production depending on the given substance and reaction. If the given substance does happen to increase the amount of production after the equilibrium has been reached, each additional unit of the substance added will likely have diminished effect and at some point could even have an inhibitory effect.
Note* - While we are talking about boosting nitric oxide production specifically, these same ideas apply to basically all foods, supplements and biological reactions.
Why Increase your Nitric Oxide Production?:
As we discussed before, increasing your production of nitric oxide can drastically improve your health as a direct of effect of increasing your blood flow. This can result in:
- Increased Energy
- Lowered Blood Pressure
- Increased Nutrient Delivery
- Improved Waste Removal
- Reduce Cold Extremities
Nitric Oxide Boosting Foods:
Without further ado let’s get into it. When assessing the blood flow boosting qualities of a given food we will mostly utilize the micronutrient composition in order to determine its blood flow boosting capability. Certain micronutrients will be more effective than others due to their rate of absorption and role in the nitric oxide synthesis pathway.
While we can consume any and all of these ingredients through strategic supplementation, it’s typically better to consume the nutrients directly through food because they will usually be better absorbed by the body. In order to view the blood flow boosting capability of individual foods we will separate these into a few categories based on their micronutrient composition.
L-Arginine Dense Foods
By consuming additional through our diet l-arginine we are able to directly increase our plasma arginine levels in our blood. Some foods that are rich in l-arginine include:
- Crustaceans - crab, shellfish
L-Citrulline Dense Foods
Interestingly enough, consuming l-citrulline has actually been shown in research to consistently increase your plasma l-arginine levels more than consuming l-arginine directly. This is likely due to the poor rate of absorption of l-arginine in the body, making l-citrulline much more effective for boosting nitric oxide levels. Some foods that are rich in l-citrulline include:
Nitrate/nitrite Rich Foods
Nitrate (NO3) and nitrite (NO2) are inactive byproducts of nitric oxide metabolism (breakdown). Recent findings have shown that nitrates/nitrites are able to be recycled in the body back into biologically active nitric oxide. Consuming foods dense in nitrates has been shown to be an effective method of increasing nitric oxide levels. Some foods that are rich in nitrates/nitrites include:
Vitamin C Rich Foods
Vitamin C acts as a very potent antioxidant in the body and can significantly reduce oxidative stress in the body. This can result in less vasoconstriction occurring due to less stress and it has also been shown to help preserve the activity of the nitric oxide synthase enzyme. Some foods that are rich in vitamin C include:
- Citrus fruits
- Citrus juices
Boost Nitric Oxide Synthase Activity
Although the mechanism behind this isn’t very clear, by increasing the stability and/or productivity of the nitric oxide synthase enzyme there is an increase in nitric oxide levels in the body. Some foods that have been shown to promote nitric oxide synthase activity include:
- Red wine
Enhance nitric oxide stability
Due to nitric oxide existing in its gaseous state in the body it is very unstable and typically only lasts for a few seconds before it is broken down. By increasing the stability of nitric oxide we can increase the number of cells which receive a signal from nitric oxide and thereby increase its effectiveness. Some foods that have been shown to boost nitric oxide stability include:
- Cocoa - Get some high quality dark chocolate!
In order to maximize our nitric oxide levels we also need to minimize the amount of vasoconstriction that occurs. As we know vasoconstriction occurs mostly in times of stress or in response to cold temperature and there are a number of signaling hormones which can induce a vasoconstricting effect.
The main signaling molecules for vasoconstriction are epinephrine, angiotensin, vasopressin, norepinephrine, cortisol and serotonin. If you are at all familiar with endocrinology (the study of hormones) you may recognize that all those hormones listed above are “stress” hormones meaning they are produced by the body in response to stress.
So, in order to reduce the amount of vasoconstriction that occurs in our body we need to minimize the amount of stress that we incur. We should also note that although these are “stress” hormones, they are not necessarily bad and all have a necessary purpose at times, but we want to reduce any excess of these hormones.
Stress comes in many forms including physical, mental and emotional stress, but on a biological level they all warrant a very similar response. So, to minimize our stress levels we need to approach stress from all of these angles. I will not be giving an in-depth analysis on how to go about doing so, but I will offer a few suggestions:
- From a nutritional standpoint, I highly recommend checking out The Thermo Diet. The Thermo Diet is a program that is designed to achieve optimal health through correcting any micronutrient deficiencies and removing any “blockers”, anything that is actively decreasing our health from our diet/lifestyle.
- On a physical level, I highly recommend performing some form of resistance training and cardiovascular training a few times per week.
- Also, making sure to walk around 10,000 steps or for at least half an hour daily is extremely beneficial from an overall health and hormonal standpoint.
- Sleeping for at least 8 hours nightly will work wonders for your overall health in just about every aspect
- Lastly, do whatever you can to put yourself in the best position possible mentally/emotionally. Find fulfilling relationships, great friends and hopefully a job/career you enjoy
As I discussed before in order to maximize our nitric oxide levels and its blood flow boosting effects. To do this we need to do our best to eliminate any foods that increase our stress levels or cause vasoconstriction.
There are five main hormones that have a vasoconstrictive effect including: epinephrine, norepinephrine, angiotensin II, vasopressin and serotonin. For a more detailed breakdown on what foods we recommend avoiding and why, again I highly recommend checking out The Thermo Diet Program, but for now I will provide a brief list:
- Food containing the Amino Acid L-tryptophan: Tryptophan is a precursor to serotonin in the body which can act as a vasoconstrictor in the body
- Polyunsaturated fatty acids: Once ingested, polyunsaturated fatty acids are broken down due to the high heat and acidity of the body. This results in free radicals and stress down the line.
- Phytoestrogens: Phytoestrogens are estrogen-like substances that mimic estrogen’s effect in the body. Contrary to popular belief estrogen is a stress hormone and will reduce blood flow if in excess.
Warning: If you are currently taking any medication for high blood pressure I do not recommend consuming large amounts of nitric oxide boosting foods or supplements. When taking medication for high blood pressure in addition to nitric oxide foods/supplements it can actually cause low blood pressure which can result in dizziness or fainting. Eating some of these foods is fine but eating them in excess can be detrimental.
The Best Supplement for Increasing Nitric Oxide Production:
Redwood is UMZU's all natural nitric oxide boosting supplement. If you want to:
- Increase Circulation
- Boost Immunity
- Improve Stamina
- Enhance Your Energy
- Reduce Blood Pressure
Redwood is exactly what you are looking for. You can find more information on Redwood here.
Whatever your reason for looking into nitric oxide boosting foods… I really hope you found this article helpful and maybe even interesting :). If you have anything to add to this article, or any helpful comments or criticism feel free to reach out to me in our facebook groups (The Thermo Diet Community Group, The UMZU Community Group) or on Instagram @TylerWoodward__.
Until next time… be good
B.S. Physiology & Neurobiology