There are many key determinants of physical health and below is an approach of looking at some key factors via our metabolic pathways.
Our physical body is like a giant factory, with thousands of millions of machines (enzymes) converting different raw materials (proteins, fats, carbohydrates, metabolites) into products. These production lines are essentially the metabolic pathways running in our body. They provide us with neurotransmitters, hormones, amino acids, organic acids, etc. that are needed for our cells, organs and systems to function normally.
These raw materials usually come from the foods we consume, or they can be end products of other production lines (metabolic pathways). Without adequate amount of raw materials, we won’t be able to have enough end products for the body to function optimally.
Enzymatic functions & cofactors
If the enzymes run too fast, we can end up with little raw materials or intermediate products, and too much of the end products. If the enzymes run too slow, we then have too much raw materials or intermediate products backing up and have too little end products downstream.
In order for the enzymes to function smoothly, we also need cofactors. Each enzyme has its own set of cofactors and they are usually specific vitamins and/or minerals, which help to regulate the speed of these enzymes. Therefore deficiency of cofactors can also affect the function of enzymes.
Besides cofactors, another key determinant of our enzymatic functions is our genes. Our genes code for the “speed” of the enzymes. They decide how fast or how slow these enzymes work, inherently. For example, the enzyme CBS is responsible for breaking down homocysteine. If our genes are designed to have a slow running CBS, we can have a higher level of homocysteine, which can increase our risk of cardiovascular diseases.
One major purpose of doing genetic testing and analysis would be looking at genetic coding for various enzymes. By knowing the inherent speed/function of these enzymes, we can have a rough estimation of whether someone tends to be deficient of a certain nutrient or tends to have higher or lower level of a certain neurotransmitters or hormones. For examples, if someone tends to have lower level of serotonin, the risk of him/her having depressed mood would be higher.
However, our genetic function can change despite the inborn coding. External factors like diet, environment and behavior can alter our genes’ expression. In other words, our diet and lifestyle can affect how our genes work, and this will in term affect the function/speed of the enzymes, therefore affecting our metabolic functions and overall health. Epigenetics is the study looking at how these external factors affect how our genes work.
Inhibitors of enzymatic function
Another group of factors that can determine the rate of enzymatic function include toxins, infections and inflammation. They tend to inhibit and slow down the function of enzymes. We could be born with well-functioning enzymes and having a well-balanced diet. But if we were being exposed to environmental toxins (e.g. heavy metals, pesticides, herbicides), chronic infections (e.g. intestinal candidiasis), or suffering from chronic inflammation because of chronic exposure to toxins, infections or stress; the function of the enzymes will still be compromised.
Making the connection
When we zoom out of an individual metabolic pathway, what we see is a map of various pathways connected with each other, just like gears. They are all connected because they either share a common enzyme or a common metabolite. As you can imagine, if one of the pathways runs too slow, either because of deficiency in a cofactor or exposure to a toxins, this can slow down other pathways that are connected together. This is how each component (diet, enzymatic function, cofactors, toxins, infections, inflammations) can have a systemic impact on our health.
Chakazul, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons