Perhaps you’ve heard of carbon dioxide before, but probably not in any positive terms. Carbon dioxide emissions are painted as the major culprit behind global warming. And the levels of carbon dioxide, also called greenhouse gas, in the atmosphere have indeed increased. Since the measurements started in 1958 at Mauna Loa Observatory in Hawaii, the levels of carbon dioxide have increased from approx. 315 ppm (parts per million), 0,031%, to approx. 420 ppm (0.042%) in January 2023. In other words, a 33% increase in a relatively short period of time. It is estimated that before 1750, when industrialization began, the levels of carbon dioxide were approx. 250 ppm (0,025%).

The increasing amount of carbon dioxide in the atmosphere means that more infrared heat from the sun is reflected back to earth and stays here, instead of returning into space.

This article, however, is about the levels of carbon dioxide in the body, but here too, carbon dioxide has a bad reputation. Generally, oxygen is considered to be the amazing life-giving substance, while carbon dioxide is just a toxic waste product that we want to get out of the body as soon as possible. However, nothing could be further from the truth.

What is normal breathing volume and what is hyperventilation?

Normal breathing at rest is about 6-12 breaths per minute and about half a liter of air per breath, giving a total breathing volume of about 3-6 liters of air per minute. But many of us breathe a lot more, often 18-25 breaths per minute and up to one liter of air per breath, giving a breathing volume of up to 10-15 liters per minute.

This over-breathing implies a low-grade form of hyperventilation, which leads to an imbalance between oxygen and carbon dioxide - we get too much oxygen in the body while at the same time removing too much carbon dioxide through exhalation.

We already have a large surplus of oxygen

At a breathing volume of six liters per minute, we only use about twenty-five percent of the oxygen we inhale. Therefore we exhale the remaining seventy-five percent. At the same time, the amount of carbon dioxide we exhale is about a hundred times higher than the amount we inhale.

The oxygen travels around the blood bound to hemoglobin. At a normal breathing volume at rest, hemoglobin is already saturated with almost as much oxygen as it can, 96-98 percent. The oxygen saturation of hemoglobin is easily measured with a pulse oximeter attached to the finger or the ear. Over 95 percent is considered normal.

When we already have such high oxygen saturation, and furthermore only use a quarter of the oxygen we breathe in, there is no purpose of breathing the 10-15 liters per minute that many of us do. Instead this over breathing, 2-3 times more than normal, gives an opposing effect, which imposes a heavy load on our body, much like eating 2-3 times more than normal.

It's all about the balance between oxygen and carbon dioxide

Just as little as a car work better because it gets more fuel, nor does our body work better because we take more breaths and inhale more oxygen. It's all about balance. Our car stops both if it gets too much or too little fuel. It needs the right amount, adapted to the needs there and then, as it differs greatly depending on whether you drive on the highway at 110 km/h or at 30 km/h in a residential area.

The same applies to our breathing. If we stop breathing, we die because of oxygen deficiency. But when we breathe too much, as many of us do, we get too much oxygen in the body and too little carbon dioxide. As oxygen is a very reactive gas, excess leads to an increased amount of free oxygen radicals, also known as oxidative stress.

The reaction is the same as when metal rusts, or when the apple's pulp becomes brown when exposed to light and oxygen. When the free radicals, the oxidation, form in the body, the number of inflammations increases. If oxidation is taking place at a higher rate than the body can handle, the aging process is accelerated. Check out this article for more information on how breathing affects your longevity: Breathe Less - Live Longer >>

Carbon dioxide pressure is more important than blood pressure

But impaired breathing isn’t just about an excess of oxygen and more inflammations. An even more far-reaching negative effect is the lack of carbon dioxide that occurs. We all know about blood pressure. It is measured in mmHg (millimeters of mercury) and a normal blood pressure is considered to be 110-130/80.

However, carbon dioxide pressure is not as well known, mainly because it’s difficult to measure and probably also because there has been a lack of interest and knowledge about breathing within the healthcare system. An optimal carbon dioxide pressure is between 40 and 45 mmHg and is crucial for our well-being.

The carbon dioxide pressure varies with each breath and therefore provides a much better view of our current health status – mentally, emotionally, and physically, as compared to measuring the blood pressure.

Seven reasons to increase the levels of carbon dioxide in the body

Carbon dioxide is constantly produced in the cells of our body, about one liter in four minutes at rest, and when we breathe, we exhale the carbon dioxide that has been built up in the body. The more active we are, the more carbon dioxide is produced. That's why we breathe more if we're out running compared to sitting on the couch and relaxing.

The seven most important reasons why it’s important to increase the carbon dioxide tolerance are:

1. Controls breathing. The carbon dioxide pressure controls our breathing, via pH. The brain stem, located between the spinal cord and the brain, controls our body's basic survival functions: hunger, thirst, breathing, heartbeat, blood pressure, fears, aggressions, flight behaviors and reproduction.

Our cells constantly produce carbon dioxide and when the levels in the blood increase, the pH goes in the other direction and decreases, which stimulates the respiratory center in the brain stem, and we inhale. At the subsequent exhalation, large quantities of carbon dioxide follow the exhaled air. The carbon dioxide levels are then lowered, while the pH is raised, and when the level of carbon dioxide again rises high enough and the pH is lowered enough, a new inhalation is triggered.

A lower carbon dioxide pressure makes us breathe faster, and over time, more shallowly.

2. Regulates pH. From school, you may remember the pH scale and that substances with a pH below 7 are acidic and those over 7 are alkaline. In our body we have over 100,000 different proteins, each designed to execute various tasks like fighting bacteria, moving a muscle, or digesting the food we eat. In order for the proteins to function optimally, the right pH balance, i.e. the right environment, is absolutely crucial.

Our main pH regulator is our breathing, as we regulate our body's pH with each breath. When our breathing habits are impaired, we exhale too much carbon dioxide, which causes the pH to rise and we thereby change the environment in our body, so that the proteins can’t function as intended.

There is a close link between the over breathing that increases the pH, and cravings for food and drink that lowers the pH - for example, fast food, fast carbs, coffee, beer, wine, candy, soda, ice cream, and cookies. They feed each other and the risk is that we end up in a vicious circle that is difficult to get out of.

3. Antibacterial. Carbon dioxide has an antibacterial effect. A study at the Karolinska Institute in Sweden showed that the growth of staphylococci was 1,000 times higher when the bacteria were exposed to normal air (37 degrees) for 24 hours compared to exposure to 100 percent carbon dioxide.

Since the 1930s, carbon dioxide is used for food packaging. Bread, cheese, chicken, and coffee are examples of products packed in 100 percent carbon dioxide. The antibacterial effect of carbon dioxide prevents the growth of germ-causing bacteria.

If CO2 has an antibacterial effect when used inside food packaging, it is reasonable to assume that it also has an antibacterial effect inside our bodies. Low CO2 levels in our body would thus provide a breeding ground for undesirable bacteria, while a higher CO2 content would reduce the risk of infections.

4. Increase oxygenation. Carbon dioxide forces the oxygen away from the blood so that it can enter into our muscles and organs, and be of use. This is called the Bohr effect after the discoverer, the Danish Christian Bohr. A simplified example of the Bohr effect are fire extinguishers containing carbon dioxide.

A fire needs a material to burn in as well as oxygen. One way to put out a fire is by spraying carbon dioxide on it, which forces the oxygen away and the fire dies out. This is similar to what happens in our body when for example carbon dioxide leaves a working muscle. When the carbon dioxide reaches the blood, to be transported to the lungs for exhalation, the carbon dioxide kicks out the oxygen from the blood, which takes the opposite direction and goes into the muscle, oxygenating it so it can continue to work.

5. Widens the blood vessels. An optimum carbon dioxide pressure keeps the blood vessels open, as carbon dioxide has a relaxing and widening effect on the smooth muscle surrounding the blood vessels. As an adult has about 100.000 km (60.000 miles) of blood vessels, i.e. 2½ turns around the globe, it’s easy to understand that a lack of carbon dioxide impairs circulation and, for example, causes cold hands and feet.

As the blood vessels become more constricted, the heart naturally has to work harder in order to pump the blood, which can lead to high (fight/flight phase) or low (freeze/exhaustion phase) blood pressure. More info about the heart is found in this article: Strengthen your heart with correct breathing >>

6. Widens the airways. Carbon dioxide widens the airways in the lungs, throat, and nose. The respiratory tract can be likened to a snorkel, where the air travels in increasingly smaller passages until it finally reaches our lung sacks, the alveoli, where the gas exchange occurs. It’s crucial that the airways are open, as it requires 16 times more effort to move the air in and out of the lungs, for each reduction of airway diameter by 50%.

Narrow airways and nostrils and a stuffy nose are logical as it's the body's defense mechanism to try to maintain an optimum carbon dioxide pressure. Carbon dioxide is produced in the body and basically, all carbon dioxide leaves the body via exhalation. In case of deficiency, the body tries to reduce the outflow by narrowing the airways.

Here are a couple of articles related to narrow airways: Improve your breathing - Improve your asthma >> and How to unblock a stuffy nose >>

7. Calms down the brain. In case of panic attacks and fear of flying it is common to get a bag to breathe in and out through so that a part of the exhaled air is re-inhaled. Exhaled air contains a lot of carbon dioxide and naturally, when we re-breathe some of this air, the carbon dioxide levels in the body are raised and the person with panic attacks or fear of flying calms down.

In one study, twelve healthy medical students were hyperventilated. At one time, they breathed normal air, and on the other occasion, the air contained five percent carbon dioxide, i.e. 100 times more than normal. The stress hormone adrenaline increased by 360 percent as they breathed normal air. During hyperventilation with carbon-enriched air, the adrenaline levels were unchanged. Low carbon dioxide levels thus lead to a strong stress response and an adrenaline rush.

In this article, we discuss how you can use breathing to calm down a stressed brain.

Carbon dioxide paves the way for oxygen

The reason why we die within just a few minutes if we stop breathing is because of a lack of oxygen. Oxygen is crucial in order for our cells, muscles, and organs to produce energy efficiently.

The major function of breathing is to inhale oxygen and exhale the carbon dioxide produced in the metabolism process. And it is easy to think of oxygen as the lifesaver and CO2 as the waste product. But it is actually the other way around.

But despite the fact that our body is constantly craving oxygen, we can understand from the seven points above that it is carbon dioxide that paves the way for oxygen, all the way from initiating the inhale of air (through the phrenic nerve that signals to the diaphragm to move downwards), to kicking off the oxygen from the blood at the cellular level.

• Inhale: CO2 tells the brain stem, by lowering the pH to the level where the breathing center is triggered, to start an inhalation.
• Airways: CO2 makes the smooth muscles in the airways relax so that they can open up and let the air into the lungs.
• Blood: CO2 relaxes the smooth muscles in the blood vessels so that they open up and circulation can occur easily.
• Cells: According to the Bohr effect CO2 lowers pH, which reduces hemoglobin affinity for oxygen and the O2 is released from the blood to the cells.

The mitochondria, where oxygen and nourishment are converted to ATP energy, heat, and carbon dioxide are also called our incinerators. These furnaces work precisely like regular fires. We can get the fires to decrease in strength by preventing oxygen from reaching the fire, and we can get the fire to increase in strength by using bellows to make more oxygen reach the fire. If we were to get it into our heads to blast it with pure oxygen, it would gain an explosive course. The mitochondria can’t work without oxygen.

Seven ways to increase the body's level of carbon dioxide

A person who weighs 70kg (154 pounds) holds approximately 1,6 liters (54 ounces) of oxygen in his body. This is a very small amount compared to carbon dioxide, which we hold 120 liters (4,060 ounces) of, in other words, 75 times as much. The reason for this is that too much oxygen is dangerous. We only take in a little oxygen at a time to ensure that the process of producing energy doesn’t go overboard.

In conclusion, an optimum carbon dioxide pressure is needed in order to oxygenate our body in the most efficient way.

1. Breathe slowly, for example by using the Relaxator
2. Physical activity
3. Rebreathe some of the exhaled air (bag breathing)
4. Absorption through the skin (take a bath, carbon dioxide enriched baths)
5. Drink sodium bicarbonate (contains carbon dioxide and can help in for example coughs)
6. Breath holding
7. Carbonated beverages

The absolute best is #1 slow breathing and #2 physical activity. #3-6 are applied when a quick effect is needed, while #7 is not particularly suitable as the drinks usually contain a lot of sugar and other things that affect the body negatively.

People with COPD and lung emphysema have high levels of carbon dioxide

People diagnosed with COPD (chronic obstructive pulmonary disease) and lung emphysema have damaged lung tissue. It makes it difficult for carbon dioxide to be transferred from the blood to the exhaled air. Therefore, these individuals have high levels of carbon dioxide despite poor health.

The breathing retraining, however, works excellent for them as well. When they improve their breathing, for example by using the Relaxator, the pressure increases in the lungs so that the excess carbon dioxide can escape via the exhaled air and the levels are restored to normal.

The exercises Hold your breath while sitting and Hold your breath while standing gives you an idea of your ability to tolerate carbon dioxide and how low or high carbon dioxide levels you have in your body. Low levels of carbon dioxide, or a low level of tolerance, means that we need to breathe often and heavily.

An essential purpose of The 7 Step CBR Program is to teach our body to tolerate higher levels of carbon dioxide, which leads to calmer breathing where we take fewer breaths per minute.

This article is based on the book Conscious Breathing.