Quite simply, without mitochondria, we would not exist.

The human body is made up of cells and according to an international team of researchers who published in 2013 in the ‘Annals of Human Biology’, there are about 37.2 trillion cells in the human body.

I can’t even imagine that number of cells.

What if I then told you that most of the cells in your body contain at least one to two thousand mitochondria each. There is likely to be ten times this number in your brain, heart and ovaries (if you have them). This means that you’re likely to have over seventy quadrillion (seventy thousand trillion) mitochondria in your body.

The function of Mitochondria

Mitochondria are tiny organelles (more on organelles later) that sit inside most of the cells in your body, and they are responsible for:

1. Energy production – they are called the powerhouse of our cells because they produce most of your energy from cellular respiration.

2. Cell death – they play a large part in determining when a cell will die through programmed cell death called apoptosis. Sometimes, cells don’t die as they should do and can grow uncontrollably.

3. Specialised purpose – depending on the part of the body in which they are located, they may have a specific purpose, for example, mitochondria in the liver convert ammonia into a less toxic substance known as urea.

Mitochondria are critical to all life, and without them, we wouldn’t exist. The performance of your mitochondria will determine how much energy you have, how you will perform in life and how long you are likely to live.

Energy Production

Your body makes energy either through anaerobic or aerobic respiration. Anaerobic respiration occurs in the absence of oxygen and takes place in the cytoplasm of the cells to provide a sudden burst of energy. Whereas aerobic respiration occurs in the presence of oxygen and takes place inside the mitochondria, producing over fifteen times more energy called adenosine triphosphate (ATP) than anaerobic respiration. ATP from aerobic respiration is created through a series of steps:

1. Glycolysis (using glucose) or beta-oxidisation (using fatty acids)

2. The Krebs cycle

3. Electron transport chain

Within mitochondria is the genetic material (mitochondria DNA) mtDNA, and magically this is only passed down by your mother. Sorry dads. The mtDNA is only passed down through the female egg because the sperm mtDNA is destroyed by the egg cell after fertilisation; and even if the mtDNA wasn’t destroyed, there are 100,000 mitochondria in the human egg and only 100 in the sperm, so the guys are outnumbered by the girls. The critical thing to note is that the natural strength of your mitochondria is linked to how healthy your mother and grandmother were before they conceived.

Mitochondria are organelles

Remember I mentioned organelles earlier? I need to explain what they are. An organelle is a part of the cell that is located within the cell cytoplasm and plays a specialised function. Mitochondria are organelles, but they share very similar characteristics to bacteria as they:

1. Are a similar size (one to ten microns long) with a jellybean type shape

2. Divide in the same way

3. Have similar inner and outer membranes

4. Have their own DNA and synthesise their own proteins

The origins of Mitochondria

Many scientists believe that mitochondria are derived from ancient bacteria and billions of years ago a symbiotic relationship formed between mitochondria and larger cells. This theory is called the endosymbiosis theory and was developed through the work of Lynn Margulis at Boston University in 1967. Richard Dawkins, the British evolutionary biologist, quoted Lynn’s work:

‘I greatly admire Lynn Margulis’s sheer courage and stamina in sticking by the endosymbiosis theory and carrying it through from being an unorthodoxy to an orthodoxy. I’m referring to the theory that the eukaryotic cell is a symbiotic union of primitive prokaryotic cells. This is one of the great achievements of twentieth century evolutionary biology, and I greatly admire her for it.’

In effect, you have ancient bacteria living within the cells of your body that are responsible for providing energy to your cells, which means that you are more bacteria than you are human. Whether you believe the origins of mitochondria or not, one thing is for sure, they are the mechanism by which your body produces energy and without them you would not exist.

Mitochondria are sensitive to what you eat, toxins in your environment, your stress levels and even light. If you genuinely want to have a limitless amount of energy and extend your health-span, then you need to look after these little guys because they are the secret to you living a long and happy life.

This is an extract taken from Chapter 1 of Limitless. If you would like to download the complete Chapter then you can do so here.