Most people are not aware that sugar has two faces to it – one side that can actually be helpful to the body and another side that is destructive to the body. When we look at sugar we see pretty white crystals of lovely sweetness. But when you look at the chemical structure of sugar you find that it is actually two different sugars chemically hooked together.The first sugar is called glucose. It is a very simple sugar that our body easily burns to produce energy. This is what doctors are measuring in your blood stream when they check your blood sugar levels. An ideal level of blood sugar is a reading around 80. That number is a measure of a certain amount of glucose by weight per a measured amount of fluid blood. It is kind of like teaspoons per cup of water, only more scientific and exact.
Blood sugar is only required by a couple of tissues in the body as an energy source as most tissues in the body actually burn fats more easily than sugar. But because it is required as the only fuel for white blood cells and a small portion of the brain, the body can manufacture its own sugar by breaking down non-sugar sources like muscle tissue to make the needed sugar. This means that even if you had nothing to eat in weeks, your blood sugar levels would still read normal because your body will manufacture the sugar it needs for those specific tissues and switch all the other tissues over to burning fats. Sugars and carbohydrates are completely non-essential in our diet. We can live very healthfully without any sugar or starch in our diet at all. It is proteins, fats, minerals, fibers, and phytochemicals, like vitamins, that are essential in the human diet – not carbs.
Glucose is like the Doctor Jekyll in the story Jekyll and Hyde, and like most doctors, should be taken in only small doses. Glucose in excess raises your blood sugar to high levels, which contributes to damage to your artery walls and nerves. Too much sugar dehydrates tissues and turns them into candy-like versions that do not work right. A good example of this is the peripheral nerve damage diabetics get and the diabetic ulcers caused by damage to the tiny blood vessels.
One other important understanding about glucose is plants will hook lots of glucose molecules together to make starch and cellulose. This means that when we eat starch, it breaks down into sugar in a matter of minutes. So when you think you are avoiding sugar by eating pasta, think again. Within minutes that pasta (or rice, or bread, or potato) will turn into glucose and come charging into your bloodstream. That is why you want to eat plants that make it difficult for our body to break down the starch. In this way the starch does not all turn into glucose at once, but does so slowly over several hours to give us sustained energy. This is usually achieved by using starch sources that are also high in cellulose and other fibers that we can not break down. They box up the starch we can break down and make it hard for our digestive enzymes to get to. Plant cell walls are usually made up of cellulose that act like a wooden box. The starch and sugars are stored inside and protected by the “wooden” box of the cell wall. We have to chew well to break open the boxes or cook the plant to burst the boxes by turning the water inside to steam in order to make the starch inside available for digestion. This is the healthy way we were designed to encounter starches in our diet. Refined foods remove all these plant walls and make the starch easily digested, which means fast digestion and absorption of the starch is converted into glucose blood sugar.
In spite of all these issues, glucose is not really the bad guy. Yes, in a refined form and in excess it produces problems. But the real bad guy in this story is Mr. Hyde. He represents the other half of the sugar crystal called fructose.
We like the fructose the most because it is twice as sweet as glucose. Table sugar is half glucose and half fructose. Two-thirds of the sweetness in sugar comes from the fructose. That is why the beverage industry invented high fructose corn syrup; it is sweeter than table sugar because it has more fructose in it.
For many years the scientific community thought that fructose was the healthy part of sugar because fructose is slowly absorbed by the intestines and does not cause a blood sugar spike like glucose does. In fact it is still being promoted by many companies as a “healthy” sugar because of this old data. The biggest example of this is the promotion of agave syrup in the health food world. Agave syrup is up to 80% fructose. It is actually a waste product from the tequila industry that has been re-purposed as a health food. Many health products proudly proclaim that they are diabetic friendly because they sweeten with agave. Most food scientists and medical nutritionists still believe that fructose is a good diabetic food. To get to the truth you have to look at the recent scientific research that shows that it is actually the fructose that is the primary culprit that causes type 2 diabetes, insulin resistance, and metabolic syndrome.
Unfortunately there is a 20 to 40 year lag time between the time researchers find something out and it becomes commonly known in the health professions. Research takes time. It has to be published and then it has to be replicated by several other researchers. Then those results are published then discussed at conferences endlessly until a general consensus is reached. When that finally happens, the information will make it into textbooks that new students will read and eventually apply once they get jobs and start seeing actual patients. So all in all a very long time passes before new research ever gets applied in the medical model. That is assuming the information is not suppressed and the funding hasn’t been cut off for any research if the initial findings threaten the profits of corporations invested in the status quo.
At this point the research on fructose is in the conference discussion stage of this process. The dangers of fructose were first uncovered about 15 to 20 years ago by biochemists when they discovered that fructose is metabolized by our livers by the same enzymes that metabolize alcohol. There is a small need for fructose in the body – about as much as you get in a cup of fruit or 6 teaspoons of sugar. Beyond that amount, fructose overloads the system and starts damaging the liver and 
setting off a cascade of inflammation that results in the formation of metabolic syndrome. It triggers the formation of fat storage amidst a storm of inflammatory chemicals that promote insulin resistance and eventual diabetes. It will even cause a fatty liver and cirrhosis just like alcoholics get. One writer I was reading described the process as “inflammaging” to link the idea that this inflammation is the root cause of early aging of the body.
So fructose is the Mr. Hyde to glucose’s Dr. Jekyll side in sugar. Sugar derived from starch, like brewers sugar, known as dextrose, does not have the fructose in it, but it also is not nearly as sweet as table sugar. I use dextrose sometimes when I am baking, but I make up the difference in sweetness with a little stevia. But most of the time I simply use my Dr Dave sugar replacement as it has no negative effects on the body. It will not brown or caramelize like regular sugar nor melt to make candies. So sometimes I resort to the dextrose for those applications.
The take away message here is that you do not need to be afraid of sugar in small amounts – less than six teaspoons per day. It should be used as a flavoring like salt or pepper, not as a food. Beyond those six teaspoons you are playing with a loaded gun. Every time you use sugar in excess of those six teaspoons you are damaging your health. So a teaspoon of sugar in your morning coffee is not a big deal. The 16 to 26 teaspoons of sugar in your can of soda or glass of fruit juice is a big deal. One piece of candy is not a problem, but a diet of candy bars and sugar filled granola snacks are a big deal. We won’t even go into muffins. There are healthy ways to make and enjoy your sweet treats. Some of these are even making it into the commercially produced world. Stevia sweetening is becoming more popular, and I expect to see more and more of these type foods as awareness of the dangers of sugar becomes mainstream.
In the mean time, it is up to us to guard our health with better choices.