Sweeteners and GLP-1 in the Modern Diet

By Kelly Gregg MD

WE LIKE TO EAT SWEET THINGS.  THAT IS NOT GOING TO CHANGE.

Modern artificial sweeteners were developed so that we can have sweet things yet decrease the sucrose in our diet.  They are sucrose replacements that do not have many calories if any, and do not affect insulin secretion which leads to the development of insulin resistance and eventual obesity or Type 2 diabetes.

Using sweeteners sounds like a great idea.  The problem is they do not work.  They simply do not lead to weight loss.

I will go over the various sweeteners and explain why they do not work.  Not only that, they cause several other problems.  Never the less, we are going to use some and I will explain which are better than others.

 

• Language: English
• Publisher: Kelly Gregg
• Release date: Oct 4, 2023
• ISBN: 9798215660157

Book preview

CHAPTER 1

SUGAR

We will start with the king of sugars, that is glucose.  Glucose is the primary source of energy in your body.  You have protein, fats, and carbohydrates.  The carbohydrate we are interested in is glucose.  Although glucose is available in various fruits and in honey, we usually do not eat much glucose.  Instead we eat things in which glucose is a part of other elements in food.

Most of our glucose comes from starches.  These are long molecules in which a glucose molecule is linked to another glucose molecule in a long string.  Throughout history, this was provided through grains such as wheat. 

Starch is not sweet.  If  you start chewing bread, you may notice some sweetness as you have an enzyme in your saliva which breaks down starch into individual components of glucose molecules.  These are somewhat sweet.

The main sweeteners in our diet are glucose, fructose, and sucrose, which is a combination of glucose and fructose.  Sucrose is sweeter than glucose, and fructose is sweeter than sucrose.  You taste these sugars in your mouth.

So you eat starch (not sweet at all), and convert this into glucose, which is sweet.  You eat sucrose, and it tastes sweeter than glucose.  You eat fructose, and it is sweeter still.

Now the fructose you eat (in fruits) is usually combined with fiber and is not easily available to the receptors in your mouth till you start chewing.  But still, fruits are often sweeter than sucrose.  For most of history this was the sweetener used.

We cease to be concerned about sweetness once you swallow the sugar.  After that we are mainly only concerned with  fructose and glucose.  We like the taste of sucrose, but after it is digested into its fructose and glucose components, it does not matter where these sugars came from.  Now we are only concerned about absorption.  Your body is designed to absorb fructose and glucose quite rapidly.  This means there is a transport mechanism used as opposed to just passive diffusion. Of course, first you must free them from fiber.  Fiber prolongs the digestion of sugar which is bound to the fiber as the enzymes in the gut must separate the sugar molecules so they can be absorbed.  Your body does a great job absorbing fructose and glucose molecules.  The glucose goes into the blood stream, the fructose goes to the liver to be metabolized.

I told you we were not concerned with the taste of sugar once we swallowed them.  That may not be exactly true as when we talk about GLP-1, we will find out there may be sweet receptors in your upper small intestines.

Although the gut does a great job absorbing these molecules, it is not perfect.  A little does pass through the small intestine to the colon.  If you eat a lot of sugar, more gets to the colon.  If you present these molecules rapidly to the gut, a little more goes on to the colon.  Although the transport mechanism works well, you can overwhelm it.  If you have the sugars bound up in fiber, even more ends up in the colon.  The  colon can metabolize fiber with the bacteria that reside there.  Increased sugar also can be metabolized.

Epigenetics is the expression of your DNA.  Your liver cells and your heart cells have the same DNA, yet this DNA is expressed differently.  For the most part, epigenetics is induced by the cellular environment.  For the cells in your body, just like the bacteria in your gut (the gut biome), this environment is driven by your diet.

I mention this because  as we will see, sweeteners affect your gut biome.  The biome is complex and represents the interaction of many types of bacteria.  These bacteria metabolize chemicals and organic molecules and create various products.  Some beneficial (the short chain fatty acids from the metabolism of fiber in your gut), some not beneficial and perhaps capable of inducing cancer.  We already know there is an extensive interaction of the biome with your immune system.  We also know the brain is affected by the biome through the vagus nerve.  The epigenetic changes are mediated both by the diet and the products from the bacteria.  Even if a molecule is not metabolized by the biome, it can still induce epigenetic changes.

Epigenetics and the Gut Biome is a different book, but it is worth noting that sweeteners will affect the gut.

The same thing happens in absorption.  If you present the glucose rapidly to the blood stream, the serum glucose level goes up rapidly.  If you present fructose molecules rapidly to the liver, more passes through the liver without metabolism and you get higher fructose levels in the blood.  You do not want either of this things to happen regularly.

Your gut biome is remarkedly complex, and the result of bacterial metabolism is that  many different compound are formed.  A prime example is lactose intolerance.  Lactose (which is not very sweet) is a sugar composed of galactose and glucose.  Some people have a deficiency of the enzyme that breaks down this sugar.  Hence, it is not absorbed and arrives at the colon.  The bacteria in the intestines (the gut biome) can metabolize lactose and  the results of this fermentation is gas, methane by bacteria, carbon dioxide by yeast.  Too much of this and you get cramping, discomfort, and gas (of course you know you can light the methane on fire).

We will see the same thing happens to sweeteners.  Some sweeteners are absorbed by the body (erythritol) and then excreted in the urine.  Other sweeteners are not absorbed but they also pass into the gut and are metabolized.  Some of these sweeteners are metabolized to produce gas and other products which does lead to GI symptoms.  Some are metabolized to other products which may cause harm to the gut.  Some are not metabolized at all, but these chemicals produce changes in the gut epithelium and in the bacteria.

I told you glucose is king, and that is because glucose is the only sugar which stimulates insulin release.  We all know about insulin.  It is released by the pancreas in response to glucose in the blood.  Your body has a glucose set point.  In other words it keeps the glucose level from getting too low (by stopping the release of insulin, releasing glucose from the liver (glycogen), and actually making glucose from protein).  It also keeps the glucose from getting too high by releasing more insulin, or, if necessary, letting glucose leave the body through the urine.  Insulin stimulates the uptake of glucose by various cells in the body.  This provides energy to the cells, and hence life.

Your body does not want to waste this precious glucose energy; hence it conserves the energy