We've all heard it shouted from the mountain top: "stress makes us sick!"
But does all stress make us sick? And what is really meant by the word "stress,” anyway? What happens to our glucose response when we experience stress, and how do our glucose levels in turn impact our body's ability to process and manage stress?
Stress and glucose have an intimate two-way relationship, but what is really going on in that marriage? It's important to understand this relationship so we can hack it at the deepest level. To kick us off, let's take a closer look at what stress really is and how it works in our bodies.
First, we must admit: not all stress is bad! Some of it is actually good.
Stress is simply a type of pressure applied to a system. Here, our body is the system. This living system is built from the biochemical language of metabolism, which is defined as the "sum total of all chemical reactions taking place to sustain life.” This goes way beyond what most of us were taught metabolism means - perhaps believing it refers only to how we make and regulate energy and/or manage our weight. In reality, everything that keeps you alive occurs along the vast interconnected biochemical "superhighways" of metabolism. This includes how we make and regulate all hormones, neurotransmitters, immune function, tissue/cellular construction and repair, detoxification, cognition and neural processing, and so, so much more. You are the planet's metabolism!
Now that we have an idea for what our system looks like, let's get back to talking about stress and how it affects our glucose and overall metabolic health.
Whether something is a “good” or “bad” pressure or stressor depends on the dose and the timing. When we are building and maintaining our bone density, load-bearing exercise or resistance training is a stress applied to our bones and connective tissue. In most people, this pressure will stimulate bone growth - a good thing. Similarly, when we are young and our immune system is developing, we are exposed to all kinds of stress in the form of pathogens from the outside world. These pathogen stressors train our immune system to recognize and protect against future invaders - also a good thing. However, we can break a bone with too much load-bearing, and we can die from an infectious illness we didn’t have the ability to fight off.
You can see that the difference between a stressor that helps or hurts is how and when we apply it and whether or not we have the internal ability to adapt to it. All stressors, whether or not they come from “external” sources such as a fight with a loved one or “internal” ones such as a food intolerance, will be interpreted by the exact same biochemistry of the stress-response system in the body.
This is why we can say:
All stress, regardless of its origin, is ultimately metabolic stress.
Stress placed on the body can occur along a continuum and is most commonly found in the form of:
You may have noticed that glucose was on that list. How can glucose itself be a stressor? We'll talk about that in a minute! But first, let's look at some other things on this list.
When most of us talk about stress, we are often referring to that first bullet point: emotional drama/trauma. Maybe you got into a fight with your best friend or find yourself worrying a lot about a situation at work. Your brain and body don't really know the difference between these things, and the primitive memory of being chased by a bear. It's all a response wired into the same system: the stress-response system, or neuroendocrine system. The neuroendocrine system is all about helping you adapt to a changing world and the changing pressures within it. It uses all of the language of metabolism to carry out its functions and can be thought of as a very large continent on the planet metabolism. Part of how we evolved to adapt to stress involves increasing our stress hormone, cortisol, which in turn, tends to increase glucose levels. This makes sense! The body needs more quick fuel to launch a sprint to safety or defense.
But these emotional stressors aren't the only stressors we have going on. Everything else on this list exerts equally important pressure on our metabolic framework - speeding up some chemical reactions, slowing others down - and perhaps overloading others into a biochemical traffic jam!
Glucose can itself be a stressor as well. Here's how we can create more overall metabolic stress when our glucose is out of whack:
When glucose rises very high into the "danger zone" after, let's say, we've eaten a giant piece of birthday cake at 8 pm, this is registered as a significant metabolic stress on the body. To respond, the body will initiate a cascade of hormonal and molecular changes that works to bring the body back to homeostasis and "normal" glucose levels.
Over time, and over repeated exposures to the higher stress of these more extreme glucose spikes, the body may fundamentally change how it responds to the incoming flood of glucose, and eventually we may arrive at a state of insulin resistance. This process of acquiring a maladaptive response (insulin resistance) is a bit more complex than we'll dissect here, but you can see how we have used the metabolic pressure or stressor of too much glucose to trigger damage in the body that now alters an important aspect of our baseline metabolic health and function.
Impaired glucose regulation can impact many other areas of metabolic function. With insulin resistance itself, we see impaired stress regulation of other areas of the metabolic planet as well. Insulin resistance increases our risk for many diseases - all affecting metabolic health as a whole.
It's also possible to have a stress-response reaction triggered when glucose falls too low (hypoglycemia). Hypoglycemia can be a metabolic stressor that leads to symptoms such as worsened fatigue, anxiety, brain fog, headaches, and more.
As you can see on our two-way street, stressors coming in from non-glucose origins can impact glucose and changes in glucose itself can impact the function of our stress-response system on a larger level. Changes in glucose can happen as a result of any change in our metabolic stress load from any one of these origins. Though it might initially feel overwhelming to consider all of these different sources of stress and wonder how we are supposed to turn this into simple, practical, daily action, it's easier than you might imagine!
Your body's response to different stressors likely won't be the exact same as someone else's response. With stress and glucose, one person's medicine is another's poison. For one person, we may see a longer fasting window improve glucose regulation and stress-management while for someone else, they may need a much shorter window to achieve optimal glucose response. Similarly, one person may have a very high glucose response to a certain food that someone else barely responds to. Everyone is incredibly unique.
Though we can often use key symptoms such as energy levels, mood, sleep quality, cognitive function, digestive function, or others that will help us interpret and gauge how stress is unfolding in our body and where our individual tolerance is at for different stressors, having a way to see our daily patterns in glucose response is a powerful tool in this process.
Finding your personal optimal “sweet spot” regarding stress takes some time and experimentation. However, here are some tips:
Track your symptoms. Do you struggle with any symptoms such as fatigue, anxiety/depression, poor sleep, difficulty concentrating, poor digestion, body pain, or difficulty managing weight? If so, consider tracking how these symptoms may change from day to day as you experiment with some of the following
As you put some of the above tips into practice, it helps to see what your glucose is doing in real time with a CGM. How do your symptoms map onto your actual glucose values? And what if you don’t have any symptoms like the ones listed above but you’re still not sure how your glucose is responding to different stressors in your life?
When we see these patterns in our glucose and are able to track changes in response to food experiments, activity, sleep, emotional stressors, and more, it can often shrink the amount of time it takes to hack into a deeper understanding of what works for our unique body, including our unique stress-response. The health of our stress-response system or neuroendocrine system is powerfully connected to our overall metabolic health. What works for you may not work the same way for someone else!