Oxygen and Your Brain

Part 1

Normal Breathing Volume

The number of breaths per minute during normal breathing is about 10 to 12. Each breath is approximately 500 ml. This provides a healthy volume as described in any University Medical textbook of 5 to 6 litres of air per minute. Normal breathing is quiet, still, calm, relaxed and regular.

Persons with anxiety and other stress disorders breathe a volume greater than normally accepted amounts. Interspersed with this will be a number of sighs. Assuming that each breath is 700ml, the average breathing volume for this person may be 10 to 15 litres of air per minute.

Chronic Over-breathing

Chronic over-breathing basically means that we habitually breathe more air than what our bodies require. In many ways, it is similar to a person developing the habit of overeating. For example, a person eating five or six meals per day over a few weeks will soon develop the habit of overeating.

Breathing is similar. If we breathe more than what our bodies require over a 24 hour period, the habit takes hold. Pulmonologist Dr Stephen Demeter confirms this when he states: (Demeter & Cordasco, ‘Hyperventilation Syndrome and Asthma’, The American Journal of Medicine, vol 81 pp 989.) “Prolonged hyperventilation seems to sensitize the brain, leading to a more prolonged hyperventilation.”

What increases breathing volume?

Breathing increases due to modern living. Factors such as strong emotions, time urgency, tension, anger, stress, anxiety, overeating, processed foods, a belief that it is good to take big breaths, lack of exercise, excessive talking and high temperatures within the home all contribute to over-breathing.

How to recognise habitual over-breathing?

At this point, you might say that you don’t over-breathe. For most people, it is very subtle. It is hidden and this is the very reason why it often goes undetected. The typical characteristics of people attending our clinics include:

  • Breathing through the mouth
  • Loud breathing during rest
  • Regular sighing
  • Regular sniffing
  • Irregular breathing
  • Holding of breath (apnoea)
  • Taking large breaths prior to talking
  • Frequent yawning
  • Upper chest movement
  • Movement of shoulders during breathing
  • Effortful breathing
  • Fast or heavy breathing at night

Carbon Dioxide

Carbon dioxide or CO2 is a gas that is created as an end product from our metabolism. The human lungs require an amount of 5% CO2 or 40mmHg. If we breathe too heavy, CO2 is exhaled or washed from our lungs. A loss of CO2 from the lungs results in a reduction of CO2 in the blood, tissues and cells.

The heavier we breathe the more CO2 we lose. Within days, the body becomes accustomed to this lower level of Co2 and breathing will be maintained to keep it at this amount. Carbon dioxide is not just a waste gas. It plays a fundamental role in the oxygenation of all organs and systems.

Functions of Carbon Dioxide

The release of oxygen from the red blood cells is dependent on the quantity of Carbon Dioxide in your lungs/arterial blood. When one is over-breathing, an excessive amount of carbon dioxide is removed from the body causing oxygen to stay bonded to haemoglobin in what is known as the Bohr Effect.

The greater the amount of air taken into the body, the less oxygen is delivered as it is not being released as readily from the red blood cells. To oxygenate tissues and organs, we need to breathe less not more.

Carbon Dioxide relaxes the smooth muscle which surrounds airways, arteries and capillaries allowing for easier air and blood flow; a 1mmHg drop (norm is 40mmHg) of arterial CO2 reduces blood flow to the brain by 2%. In other words, oxygenation of your brain significantly decreases when you breathe heavily.

The heavier you breathe- the more you feed your hyperventilation or over-breathing related problems. Have you ever noticed that you get light headed after taking a number of big breaths? Have you ever noticed being very tired in the morning after a night breathing through your mouth? How tired are you after a day’s talking? You might also notice that as you get stressed your breathing gets faster resulting in mental block and difficulty in making decisions. Heavy breathing feeds anxiety and stress. The calmer and quieter you breathe, the more your blood vessels open enabling better circulation and distribution of oxygen throughout the body including the brain.

Part 2

Over-breathing Contributes to Stress, Anger and Anxiety

Lower carbon dioxide within the blood causes a constriction of the carotid artery which is the main blood vessel going to the brain. The extent of constriction depends on genetic predisposition but has been estimated by Gibbs (1992) to be as much as 50% for those with anxiety and panic attacks. This finding is also supported by Ball & Shekhar (1997)

Other researchers including Balestrino & Somjen, 1988; Huttunen et al, 1999 have demonstrated that CO2 reduces cortical excitability. Cited in Normal Breathing- the key to vital health; “breathing too much makes the human brain abnormally excited due to reduced CO2 concentrations. As a result, the brain gets literally out of control due to the appearance of spontaneous and asynchronous (“self-generated”) thoughts. Balestrino and Somjen (1988) in their summary directly claimed that: “The brain, by regulating breathing, controls its own excitability“.

Dr Robert Fried, professor of psychology states that “the first stage of chronic graded hypoxia, (insufficient oxygen) which has repeatedly been shown in the case of chronic hyperventilation is lowering of mood and activity. (The Hyperventilation Syndrome- Robert Fried)

Cardiologist Claude Lum comments that; “Hyperventilation presents a collection of bizarre and often apparently unrelated symptoms, which may affect any part of the body, and any organ or any system.” He further labels hyperventilation syndrome as the fat file syndrome noting that patients go from doctor to doctor in an attempt to get help for their symptoms. However, because chronic hyperventilation is overlooked in most instances, the patient might be told after a series of tests that there is nothing wrong with them, thus increasing the size of the patient’s file and further adding to their anxiety. 

What is Fat File Syndrome?

Louise’s account (name changed):

“For example, because I am prone to worry and overthink things. I got myself worked up into a right state about my symptoms. I was convinced at different times that I had a brain tumour, MS, a heart problem, bowel cancer etc. I had blood test after blood test, an ECG test, a scan, and nothing was found to be wrong. My whole family and my doctor, and probably most of my friends, think I’m a hypochondriac…but I knew there was something not right. I just didn’t make the connection to my breathing, so my symptoms went on and on and I felt like I was going mad. For lots of people, reading your book will be a real epiphany…and they might need some reassurance early on that they’re not alone and not mad after all. Also that a lot of the symptoms will go away.”

Stress, Anger and Anxiety Contributes to Over-breathing

According to the famous physiologist Walter Cannon, stress activates the fight or flight response. Meeting deadlines, financial pressures, time urgency, marital issues, the pressure of raising children, doing well in our work and many other factors add to stress levels. 

Old Brain New World

Stress is a natural reaction which we have developed throughout our evolution to ensure the survival of our species. It is invariably our body undergoing a chemical change in response to environmental conditions. Thousands of years ago, our main threat was from predators and nature.

When confronted we had two options to deal with it. The first was that we fought it, the second was that we ran away from it- as fast as we could. As our bodies were required to perform intense physical activity, our physiology changed in the following way;

  • Our breathing volume increases
  • Our heart rate increases
  • Adrenaline is pumped into our system
  • Our pupils dilate
  • Blood is diverted from internal organs to our arms and legs
  • Diarrhoea may occur (lightens our weight before flight)
  • Our blood coagulates in case of injury

However, today our society and environment have changed at a far greater pace than what our bodies can adjust to. We react to the stress of today with the same reaction as we did thousands of years ago. We are in a traffic jam rushing to get to a meeting. The fight or flight response is activated but there is no need for it. Our heart rate increases, blood is diverted to skeletal muscles, our breathing increases- we are primed for physical activity but yet we are sitting still. The result is we are running on the inside and sitting on the outside.

The heavy breathing arising from the fight or flight response results in a washing out of carbon dioxide from the lungs. This causes a narrowing of blood vessels thus reducing blood flow to the brain. In addition, the release of oxygen from blood cells is less due to an inhibited Bohr effect. This in turn increases self generated and more random thoughts. With uncontrolled thought activity, we feel unable to cope in everyday activities and this further increases our anxiety. A vicious circle has commenced with stress increasing our breathing with this in turn feeding our stress.

It is only by bringing your breathing volume to normal levels that you deal with the physiological aspects of stress and anxiety. Undischarged stress is so bad for the organism and this is principally due to the adaptation to a habit of over-breathing. Optimal breathing allows for a normalisation of the partial pressure of carbon dioxide within the lungs thus improving oxygenation of the brain and resulting in far less brain cell excitability.