What is a hormone? I’m sure we all have heard of them, probably in the context of sexual hormones like testosterone and estrogen. Simply, a hormone is nothing more than a messenger molecule that runs around the body to turn on or off certain functions in the body. They regulate almost everything in the body such as muscle growth, hunger, satiety (the feeling of being full), sexual function, blood glucose and so many other functions. Depending on the type of hormone, they are either broadcast out from the endocrine glands to look for specific target cells or secreted in nearby cells such as in the nervous system and muscles.
Here is an example of how hormones work. You’ve probably heard of “fight or flight”, meaning you have encountered a situation that your ancestral brain sees as something dangerous. This can be something life threatening, like a car slamming on it’s brakes, or something that surprises you like a loud noise next to you. Our ancestors had super knarly problems to deal with, such as a sabre tooth tigers jumping from the bushes. Do we fight it and maybe die or kill it and maybe have dinner? Do you run and maybe live another day or become the tigers dinner? Either way your body quickly prepares for both, whichever you decide to do, fight or flight. The human body does this by sending out hormones that control everything from heart rate to muscle response to focus and eyesight, all in a split second. In this example, you are confronted by something that surprises you, your adreanal glands that are attached to your kidneys pump out epinephrine, this hormone is released into your bloodstream, to your broncheal system and enlarges it so you can breathe better and get more oxygen. It goes to your arteries and narrows them to increase blood pressure to get more blood and oxygen to your muscles so you can move or fight. It narrows your field of vision so you can focus on the target, your fine motor skills diminish to give your big muscles more use. At the same time, the hormone cortisol is released to push glucose to your muscles so you can move, anytime glucose is in the blood, insulin is released to get the glucose to the cells. And now you are ready to fight whatever is in front of you, or run from it. That’s an example of how hormones work in the body.
There are about 50 known hormones in the human body. They do all kinds of things, sometimes they work together, sometimes they work by themselves, some attach to receptors outside of cells and some go inside the receptor cell. Hormones are broken into two categories, water soluble and fat soluble. This determines if the hormone can travel in the blood all by itself or if it needs to be attached to a protein, if it can bind to the inside or the outside of a receptor cell, and how the hormone is metabolized. For instance, fat soluble hormones can bind either inside or outside the cell where water soluble can only bind to the outside. Is any of this important? Not really, it just gives you some more information on how hormones move about.
What I do find interesting and more relevant to the food we eat is how hormones are made. Hormones have to be manufactured by the body and there are three known categories that hormones fall into. These are Steroid hormones which are fat soluble, Amino Acid Hormones which are water soluble and Polypeptide hormones which are also water soluble. Steroid hormones are made from cholesterol and include some of the well known hormones, testosterone, estrogens and progesterones to name a few. Amino acid hormones are made from amino acids, the building blocks of protein. These hormones are stored in endocrine cells until needed and can influence gene expression. Polypeptide hormones consist of long chains
of amino acids, some are several acids long, some are 200 acids long. Polypeptide hormones are also stored in endocrine cells until needed and regulate functions such as metabolism, growth and reproduction.
Hormones play a large part of your overall metobolic health and of course weight control. Not just what we eat but when we eat, stress, exercise and sleep all contribute to metabolic health, or the lack of it.
One of the hormones that gets a lot of attention is Insulin. Insulin is a peptide hormone that binds to glucose and allows glucose to enter cells. Insulin also takes what the cells do not use and stores it away as fat.
