Dear Friends and Readers,
I have spent hours researching the very “nuanced” subject of sugar. There are three main types of sugars glucose, fructose and sucrose. However simple this may appear sugar is far more complex.
All tissues in the body have the chemical machinery to break down glucose and use it for energy production. This differs from fructose, which can only be processed through the liver.
Glucose is also known as dextrose and is the primary sugar that the body makes from food. Glucose is carried through the bloodstream to provide energy to cells in the body. Cells cannot use glucose without the help of insulin. Glucose, a simple sugar (a monosaccharide)the body produces it from protein, fat and, in largest part, carbohydrates. Ingested glucose is absorbed directly into the blood from the intestine and results in a rapid increase in blood glucose.
We mostly derive glucose from starches, but gluscose can be found in many foods. When we eat starches, our body converts them to glucose, which raises blood sugar levels and supplies your body with energy. Cells cannot use glucose without the help of insulin.
Your body metabolizes glucose via the intestinal tract, causing a rise in blood sugar. In order to return your blood sugar to a normal level, the pancreas releases insulin, which is a storage hormone. The insulin binds to the glucose and carries it to the cells that need extra energy, storing any remaining energy in long-term storage to become fat cells.
Problems occur when our blood glucose is continuously elevated. Eating highly processed foods, simple starches (white flour, white rice), and foods containing sugar elevate blood glucose significantly. For a while, the pancreas can handle this workload; however, over time it becomes exhausted and unable to efficiently release insulin any longer. This can result in the chronically elevated blood glucose levels found in type 2 diabetes or metabolic syndrome. At the same time, because insulin release is now inefficient, glucose is no longer being delivered to the cells that need it, resulting in cell starvation.
Fructose occurs naturally in fresh fruits, giving them their sweetness. Fruits contains relatively small amounts of fructose providing your body with just a little bit of the sugar, which is very easily handled.
Unlike Glucose, Fructose can only be processed in a few tissues, mostly the liver and to a lesser extent, the kidneys. Our liver must first process fructose before it can enter a metabolic pathway leading to energy production. To a lesser extent, your kidneys can also metabolize fructose.
The problem with fructose is that when you consume large amounts of it in its concentrated form (agave, crystalline fructose, high-fructose corn syrup), it goes straight to your liver. This places a heavy toxic load on your liver, which must work very hard to process it, sometimes resulting in scarring. Additionally, fructose is converted by the liver into glycerol, which can raise levels of triglycerides. High triglycerides are linked to increased risk of atherosclerosis and heart disease. Triglycerides can build up in liver cells and damage liver function. Triglycerides released into the bloodstream can contribute to the growth of fat-filled plaque inside artery walls. Free radicals (also called reactive oxygen species) can damage cell structures, enzymes, and even genes. Uric acid can turn off production of nitric oxide, a substance that helps protect artery walls from damage. Another effect of high fructose intake is insulin resistance, a precursor to diabetes.
Sucrose is a disaccharide, or two-unit carbohydrate, linking glucose and fructose molecules. You may know it as table sugar, since most table sugar comes from sugar cane or sugar beets, and both sources are among the higest in sucrose. However, all fruits and vegetables contain some sucrose, as it is the main product of photosynthesis, the process that all plants use to convert the sun’s energy into food. Your body primarily digests and absorbs sucrose for energy production.
As a disaccharide, sucrose is too large to cross cell membranes. As a result, your body must first break it down through enzymatic digestion before it can absorb it. Sucrose digestion begins in your small intestine with a process called hydrolysis. In this chemical process, a water molecule helps to break the bond between glucose and fructose with the assistance of sucrase. Sucrase is an enzyme of the small intestine that your body needs to digest sucrose because it specifically breaks the glucose-fructose bond that occurs in sucrose.
However, acording to The American Journal. of Clinical Nutrition none of process modalities matter. Sucrose, high fructose corn syrup, honey, and many fruits and juices deliver the same sugars in the same ratios to the same tissues within the same time frame to the same metabolic pathways.
However, don’t give up. Understanding the conversion of grams of sugar to teaspoons of sugar is the first place to start. . Four grams of sugar equal one teaspoon of sugar. Therefore, a dessert with 16 grams of sugar per serving equals four teaspoons of sugar. Not bad you say, that’s like eating an apple which contains 19 grams of sugar. Or why not a 12 ounce can of coke has 35 grams of sugar? That’s only eight teaspoons of sugar, right? But this must all be taken into context. There’s the issue of nutritional value per teaspoon of sugar. Your body will derive the value of the nutrients from an apple verus a can of coke or a nutrionally worthless dessert which is likely to be full of fat.
The next stop is understanding the Glycemic Index (GI) which is a relative ranking of carbohydrates in foods according to how they affect blood glucose levels. This valuable index is limited because it’s difficult to compare a gram of alcohol to a gram of apple, because no one eats a gram of an apple. To address this problem, researchers have developed the idea of glycemic load (GL), a numerical value that indicates the change in blood glucose levels when you eat a typical serving of the food. For example, a 4.2-ounce (120-gram) serving of watermelon has a GL value of 5, which would identify it as a healthy food choice. Another example would be a 2.8-ounce (80-gram) serving of raw carrots has a GL value of 2.
If you are really interested in in the glycemic load index Sydney University has a table that shows the glycymic index of over 750 commonly consumed foods.
My quest to understand sugar and how it affects blood sugar is a result of my own sugar addiction and how best to manage my cravings for sugar and simple carbohydrates. I have learned that dried fruit is a pure form of glucose. I have also attempted to utilize the glycemic index when choosing added sweetners.
I have provided the glycemic indexes for sugar, honey, agave, maple syrup and agave and a few others.
Barley Malt 42
Brown Rice 25
Cane Juice 43
Coconut Palm Sugar 35
High Fructose Corn Syrup 68
Maple Syrup 54
In my next blog, I’ll provide possible solutions to the most efficient and healthy way to fuel your body.
Brianna S. Clark
The Addict Writes