Complexity and Human Health – Part 3, A Complex and Biological System

Your body is a complex, biological system. 

You've now seen how a complex system is one that you can't fully understand by breaking apart into its components. It's not that it would be too much work to do so, but it's literally impossible because, by definition, you lose important information about the system as soon as you start to break it apart.

Fortunately, you don't have to rely on the reductionist approach to understanding the workings of the system because it has a special property.

Your human body is biological, which means it is designed to be self-sustaining.

That is, it takes care of itself, given that two key needs are met:

1. The biological system is given sufficient amounts of the proper resources
2. The biological system remains within a healthy stress balance

When a biological system maintains healthy functioning over time, receiving the resources it needs (while being able to excrete any waste), this is termed homeostasis. Let's look at this concept because it will play a crucial role as we move forward.

Homeostasis

If we take any healthy biological system (e.g. a forest, a lake, an organ) and isolate one factor (number of squirrels in the forest, amount of fish in the lake, amount of fat stored in an organ), it would look something like this:

• the amount of that particular factor would fluctuate over time, rising and lowering while remaining close to a mean value
• if that system is not too stressed, that factor is going to stay within a safe and healthy operating window (below, represented as between upper and lower sustainable limits)

Now, if that system is stressed in certain ways, that value may fluctuate to a greater extent, perhaps leaving that healthy and sustainable operating window. You can think about the amount of stress and the corresponding impact on the system in two scenarios:

1. a stress that causes a change in that variable such that it leaves the healthy and sustainable operating window just a bit. In this case, the system is able to bounce back and return to a state of homeostasis
2. a large stress that impacts that variable significantly enough that irreversible damage is caused. In that case, it might even cause the death of that system.

As we see, there are different types of stress, and not all are actually harmful (many are actually beneficial, but we'll save that talk for another time).

The system, itself, is really only harmed when that stress becomes too large or appears for too long.

Let's translate these general concepts to our specific case: the human body.

The human body is a complex system made up of innumerable sub-systems.

The most useful way to talk about sub-systems supporting the health of the human body is by talking about tissues and organs.

Additionally, you can think about the many biomolecules that transmit material, resources, and information from sub-system to sub-system.

Finally, sometimes it is useful to think about specific cells and the biomolecules that make them up, but again, you don't want to get lost in the function of each and every cell, tissue, or biomolecule. Instead, you want to understand general functioning that is most responsible for defining your state of health.

Let's take one very important example:

Blood sugar homeostasis:

Note: sugar includes glucose, fructose, and other 'oses, although, I'll keep it simple and most relevant and speak of glucose

Glucose is one of the body's primary sources of fuel. The body maintains a constant supply of glucose to be readily available at any point for any tissue in the body in need of energy.

However, it's crucial for this course (and your health knowledge) to understand this key point: when blood sugar concentration elevates too far, that sugar becomes toxic to tissues and biomolecules throughout the body.

Because of this, the body has systems in place to keep blood sugar concentration within a tight window. Note: I've drawn that "healthy" window between the bounds of ~70 - 120 mg/dL, although we could have a deep discussion about what this "healthy" upper boundary really is.

• Remember, if blood sugar concentration elevates too high, that sugar becomes toxic.
  1. As it begins to increase above a healthy threshold, glucose may interact with other biomolecules or tissues that come in contact with the bloodstream (glycation) rendering them useless or causing lasting damage. Over time, this can cause significant damage that may arise as serious symptoms for that individual (e.g. loss of limb, blindness)
  2. As glucose concentration increases even further, that toxicity becomes acutely life-threatening

Because of this, the body has evolved such that keeping blood sugar in check is the priority. It does this automatically, without your conscious intervention.

You can note that it does this through the action of two key hormones: insulin and glucagon, although there are a significant number of other biomolecules at play that impact the functioning of this sub-system.

Note: insulin is one of my favorite hormones to talk about. However, it won't be playing a role in this short course. But, if you are interested in learning more, check out my whole series on it, including insulin's role in supporting a healthy weight.

The key point here is this: most individuals do not have to consciously work to constantly maintain their blood sugar, just like humans have not had to manage this task since the beginning of our existence. The body, itself, manages this task, just like it manages how much fat is stored away and how that fat is broken down and used as a fuel source.

Similarly, the body is programmed to be able to manage energy balance throughout all systems supporting the body, and that includes sugars and fats (as two key energy-containing biomolecules) stored across systems (e.g., glucose stored as glycogen in the liver and muscle tissue; fat stored in adipose tissue, etc.).

The True Problem

Of course, you may be thinking about one problem with this setup: so many human bodies in our modern world are not so great at regulating their energy within and across systems:

• It is common to experience unstable blood sugar
• it is common to experience the excess accumulation of fat
  • not just in adipose tissue, but also in the liver, skeletal muscle, and other organs

As a matter of fact, as we see in our modern world, the ability of the human body to maintain metabolic homeostasis has been lost for most individuals.

This is exactly the point I wanted to arrive at so that we can clarify what is happening.

For anyone who experiences these symptoms (e.g., large fluctuations in blood sugar or excess fat storage), the problem is not necessarily that you have failed to control your metabolism. Instead, the problem is that your metabolism has become dysregulated.

The difference means everything because it determines the approach that you will take as you move forward making health-conscious decisions in the future. This difference means that you will be:

• moving away from trying harder to have more control over your behavior
  • forcing yourself to eat less; or to eat foods that you don't want to eat
  • forcing yourself to go exercise harder (even if you're already exhausted)
• moving towards using a wiser approach to take simpler actions that help support your body in its effort to regulate energy balance and maintain healthy metabolic function:
  • finding a healthy way of eating that you enjoy as it truly supports your health
  • finding regular ways to move your body that you enjoy while supporting your health
  • finding a way to balance the stresses in your life so that you can more naturally regain and maintain a good state of health

Note: if you don't currently suffer from any of those obvious symptoms, don't tune out because you are absolutely still relevant to the discussion here!

• for one, it is likely (based on population statistics) that you do experience some of what we are talking about, but that you aren't aware of it due to a lack of obvious symptoms.
  • the most important example of this is the development of insulin resistance, a state of energy dysregulation and metabolic dysfunction that can arise before the onset of obvious symptoms

If that's not the case for you, this is still relevant for remaining healthy as you move forward:

• • freeing you from ever thinking you need to control your energy levels (yes, that includes your weight)
  • providing you with a useful framework to keep you healthy over time

Thinking of your body as a complex, biological system

This lesson contains a lot of technical information. Note that the point is not for you to remember all the details.

The whole point is to get at this small but powerful nugget: your task is not to work harder to better control energy across different systems supporting your body.

Instead, your task is to be aware of how your behaviors impact your body's ability to maintain energy balance.

See the difference? It's subtle, but it means everything for how you move forward making health-conscious decisions:

• a healthy individual does not need to micromanage his or her blood sugar, fat stores, or other energy stores - because the human body has systems in place to ensure that these energy levels maintain within a healthy range
• we all do need to be mindful of how our behavior impacts the ability of these systems to function because the unfortunate reality is our general behavior in the modern world does not support these essential abilities

As we move forward thinking with this new mindset, we become capable of making powerful choices that truly support the health of our bodies.

We'll see how to do that in Part 2.