Breathing and your immune system

Since the declaration of the coronavirus pandemic, breathing and immunity have made the news in every country in the world. In recent weeks, we have seen frightening images of people having their breath stolen by a virus. If the coronavirus has reminded us of anything, it is this: how important breathing is and how vital immunity and preventive medicine are. Because breathing is directly related to lymph flow, and lymph flow is directly related to immunity. Read on to see how breathing is related to immunity.

We breathe from the moment we are born until the moment we die. However, most of us are barely aware of breathing.
We learn at school that the lungs absorb oxygen and release carbon dioxide, but beyond that, few of us know anything more about the vital mechanics of breathing and how the act of breathing affects other parts of the body.

The intercostal muscles and the diaphragm are the main muscles of respiration, but there are numerous “accessory” muscles of breathing in the back, chest and neck. Theoretically, these accessory muscles should only be used during times of exertion, but the reality is that most people use these accessory muscles continuously.

The diaphragm muscle is located between the lungs and the abdomen. I usually say it is “the floor of the lungs and the ceiling of the belly”. When we inhale, the diaphragm moves down. When we exhale, it moves up. It’s almost like an elevator that only runs between two floors. When the diaphragm moves up and down in the centre of the body, it is comparable to the piston of a car engine. Its rhythmic movement generates a constant and cyclical pressure difference in the abdominal cavity.

Let us compare the movement of the diaphragm with the flow of a piston in an internal combustion engine. When the fuel is burned, it releases energy. And this energy moves the piston back and forth, creating pressure differences that feed the crankshaft and spin the wheels.

The deep breathing and lymphatic flow

The pressure differences in the abdominal cavity created by diaphragmatic breathing also cause a series of pressure differences that then generate movement in the body. We will now focus on only one of these: the lymphatic flow generated by deep breathing.

The vascular, lymphatic system, or merely the lymphatic system, is a circulatory system not unlike the cardiovascular blood system. Of course, the lymphatic system doesn’t have the heart to pump out the lymph. It has no arteries, only delicate vein-like vessels that carry the lymph from the extremities to the centre of the body.

The goal of lymphatic flow is to get the lymph back into the bloodstream. Some lymph flows back to each lymph node (we have 600-800 lymph nodes in the human body), but the vast majority has to flow back into the subclavian vein. This vein, as its name suggests, is just below the collarbone. This means it is right in the upper body, in the throat.

The curious and winding path of the lymph

Lymph moves due to muscle pumping and breathing. We need to move and breathe to have a healthy lymphatic system. Specifically, we need to take deep breaths with the diaphragm to pull the lymph from the periphery (the farthest parts of the body) to the centre.

Imagine for a moment a mountain landscape: there are hills and valleys, and small streams at the top of the mountains join to flow down to form large rivers in the valleys. The lymphatic system looks a lot like this: small lymphatic capillaries throughout the body join together to form larger and larger vessels that eventually join together in the thoracic duct.
This thoracic duct is the largest lymphatic vessel in the body and runs parallel to the spine. It begins with a reservoir called the chyli, which is located just in front of the twelfth thoracic vertebra. The thoracic duct carries the lymph up into the subclavian vein.

Here, breathing influences both the accumulation of lymph in the chyli and the movement of this lymph upwards in the thoracic duct.

Finally, to complete the journey from the bottom to the top, the thoracic duct has to cross the diaphragm. There are several “holes” in it that allow the elements to move up and down. Well, the thoracic duct passes the diaphragm at the “aortic hole”.

When we take long, deep breaths, not only does the lymph flow more easily into the chyli, but it also flows more gently into the thoracic duct. Consequently, lymphatic return improves with proper breathing technique. We can almost compare the effect of the lungs’ pumping on the lymphatic system with the impact of the heart’s pumping on the circulatory system.

Why is it so essential to get the lymph back into circulation, and how does it affect immunity?

1. The first line of defence

The lymphatic system acts as the communication system of the immune system. Lymphocytes are found in lymph nodes and organs, as well as in the blood. Lymph nodes are the body’s first line of defence against disease. The danger signals about infections and invaders are transported from the lymph nodes to the thymus gland through the lymph flow. The thymus is the “brain” of the immune system, but it needs to be informed of threats. The thymus is located behind the breastbone and below the collarbone. Once alerted, it can create highly specific “soldier” cells to fight disease.

2. Cellular detoxification

The detoxification organs in the human body are the liver and the kidneys. Once the lymph returns to the bloodstream, the toxins it carries can be sent to the liver for enzymatic neutralization and the kidneys for ultrafiltration. If the lymph does not return to the circulation, the toxins remain in the tissues and can cause heartburn, chronic inflammation, and impede our ability to fight infection. Many people have chronic skin and toenail infections, and this may be related to poor lymphatic drainage.

3. Early warning system

In airborne diseases such as influenza or coronavirus, the sentinel lymph nodes are the adenoids and tonsils. If they “catch” an invader, they immediately alert the thymus gland so that an immune response can be mounted. It is easy to see why, therefore, good lymphatic drainage is essential for an excellent immune response: the lymph nodes catch the invaders, send messages quickly to the thymus, and we can defend ourselves quickly. Good lymphatic drainage is promoted by deep breathing. Then, by taking deep breaths, we have a chance to respond rapidly to threats.

And one more thing…

Healthy breathing is through the nose. Every time we breathe through our mouths, we are exposed to particles in the air that can settle directly into the respiratory system. This mechanical aspect of breathing is elementary to correct and very important for good health.

So, now that we understand how good breathing habits are related to immunity and health let’s practice self-care and preventive medicine with every breath – to your (good) health!