Stress and Metabolism, part 1
Metabolism is the utilization of nutrients by our cells transforming them into molecular components for internal functioning of self and other parts of the body. It also involves the movement of energy in and out of storage areas around the body, and into every cell in the body. When we eat, our digestive system absorbs the food. Any excess food is stored away so nutrients can be used during the hours in between meals. Additionally, anytime we enter “fight-or-flight” mode, these stored nutrients are released for use into the bloodstream.
The process of food entering the gut then going into your bloodstream for utilization involves three types of food constituents coming from macronutrients- proteins, carbohydrates and fats.
Proteins are made up of amino acids, and these amino acids are small molecules that together compound into a protein. When we eat proteins, our stomach and intestines do all the work to break it down and absorb them. What we end up dumping into our bloodstream are amino acids. They become the building blocks of our body-proteins.
Carbohydrates are complex types of sugars that become glucose–or simple sugar–when they go from the gut to the bloodstream. There is a process of breaking down these carbs into simple sugars, and the digestive system is in charge of that. So, once this process takes place, they become simple sugars.
Fats go from our guts to the intestines and break down into molecular parts: fatty acids and glycerols. Our basic fuels for our body are in the form of simple sugars, fatty acids and glycerols, and amino acids.
Not all the amino acids, carbs and fat we take in are going to be consumed by our cells however. As we eat, our cells are well fed, and excess becomes surplus. What does the body do with the surplus? It stores it away. Between meals, our cells will require additional constituante nutrients. In other words, cells in our body don’t contain a large amount of nutrients; the cells don’t save a lot inside themselves. The stored excess is what the body uses to feed our cells during the hours we are not eating. Using a metaphor, this is like saving money in a checking or savings account. You get a paycheck, and you don’t spend it all, but use what you need and save the rest to pay other bills later in the month. As additional expenses come, you use what you’ve saved, and if there is an emergency there is the money to take care of the problem. It’s the same with the body between meals. You save excess, and the body takes out of that excess so cells can be fed. If there is danger, the stress mechanism is activated and the fuel is there to run so you can get out of the dangerous situation.
The storage areas of these constituents are located in different parts of the body. Carbs and fat are stored in adipose–or fat–cells, liver, muscles. Amino acids are saved in muscles and the liver. These storages are saved in glycogen.
How does our body do this? How does it know when we have excess, and how is it stored away? What hormones are involved in all this? One of these hormones is insulin. Insulin can be secreted even in anticipation of meals, before we eat. This is activated by the brain, which sends information to the pancreas. Insulin not only transports sugar to cells, but also transports excess nutrients for storage. The way our bodies work with these hormones plans for the future so that our cells can be fed in times of need.
Let’s take a look at the effects of stress, starting with acute stress. If we are running from a bear, we need energy for our muscles; energy to focus and power the entire body to ensure that we can run to safety. What our bodies do to provide this needed energy is reverse the usual storing process. Meaning it takes these storages of energy and transforms them back into the original constituents and dumps them into the bloodstream, rushing circulation. It’s like taking money out of the bank to pay for our bills. Other hormones like glucocorticoid and epinephrine and sympathetic nervous systems participate in this process, including glucagon. These hormones and chemicals are molecules made by the body and help take these stored nutrients out to our circulation so they become sugars. They do the same with proteins and fats, dumping them into the bloodstream. This is done because, when we’re running for our lives, we need as much energy as possible to ensure we run as fast as we can. A great amount of energy is required, so these excess nutrients must be placed in our circulation.
In addition to this, the body stops the secretion of insulin. This is a good idea in fight-or-flight situations of acute stress because the last thing we want to do while we need to use our stored nutrients is to store them back up again. So the brain sends signals to the “banker” saying “Don’t store all of this back up, we need it to survive.” What is secreted instead is glucocorticoid, epinephrine and glucagon.
The transition to running for our lives and having completed this cycle after saving our lives is needed for the body to reverse everything. We need to go back to normal. Sugar gets stored back up again. Glucocorticoid, epinephrine and glucagon stop being produced.
But what happens when we have chronic stress instead of acute? Acute is temporary stress, and is needed for many bodily functions and mechanisms, including fight-or-flight. When chronic stress is present, it creates a real problem for our metabolism and other mechanisms. The stress mechanism is turned on several times over the course of the day due to some psychological problems that come by way of worries, hyperactivity, perfectionism, feeling victimized or not wanted and other manifestations when we have chronic stress. This affects metabolism- remember you’re going to be activating this response over and over again. In this state we believe there is a constant threat. We’re not good enough; there’s an issue with a family member or a neighbor, etc. The body will shut down insulin and remove stored sugar to be flushed into circulation. An hour later we may feel better, and everything is put back into storage. If this cycle repeats over and over however, it creates a problem. Energy is mobilizing through all these cycles, restorage and putting them back again, over and over. After a while of this occurring our metabolisms become inefficient.
The other problem with this is diabetes, because of the constant cycle happening all day. There are two types of diabetic problems: One- not producing enough insulin. Two- insulin is not being accepted by our cells, causing receptors to shut them down.
A simplified way of presenting how diabetes takes place is this: Something goes wrong with the pancreas and cells due to receptors shutting down and not accepting insulin. This means we gain excess sugar in the bloodstream, rather than in storing it. Because of this rollercoaster of stress mechanisms throughout the day, the pancreas gets damaged.
Storage issues happen as well. We’ll have excess in our bloodstream, but we’ll need insulin to store it back up. However, since insulin isn’t working, we can’t store it back up. So we get too much sugar in the bloodstream due to this. Where do these excess nutrients go? Well the brain has to do something about this nonsenses and send messages to the liver to stop sugar excess and convert them in fat to be sent to adipose cells. This problem increases the size of our body, causing overweightness that initiates around the viscerals were adipose cell are located because they have more receptors for insulin. So all that added abdominal fat make us rounder.
Chronic stress causes a problem in the metabolism and production of sugar. This is seen in people who have metabolism issues by the increased amount of fat cells inside, incrementing weight and size. It takes years before internal damage due to this fat increase problem can become diagnosed. There are other issues, such as overeating or loss of appetite. All of this stress pushes us into gaining bad habits, affecting our metabolisms. In our next blog we’ll continue to look at the effects of stress on the metabolism.