Most persons reading the “sugar” in the article, I guess, immediately see a white powder on the kitchen table that you put on food to sweeten. And they think “that’s not healthy!” And they may have heard of Refined vs. Natural Sugars; the former bad and the latter good for nutrition.
Well, Physician’s Notebooks should disabuse you of these erroneous notions.
The sugars are the structural units of carbohydrates (CHDs, one of the 3 nutrients in your foods, besides the fats, aka lipids, and the proteins).
Glucose is the primary sugar. All carbohydrates you eat will get digested, in stomach and intestines or metabolized in the liver. Sugar is used mostly to produce energy for your daily motions.
Types of Sugars in Carbohydrate: Simplest are the monosaccharides (“mono-,” or “single”; also commonly referred to as natural sugars). These are important in producing energy from food that allows us to move and function. Glucose is the most important natural sugar.
Hyperglycemia & Hypoglycemia: Glucose in blood when high is hyperglycemia, as seen in diabetes mellitus, and when too low due to a diabetic injecting self with excess insulin is hypoglycemia, which causes cold sweat, fainting and, if prolonged, death. For best body functioning and no unpleasant symptoms, it needs artery blood glucose concentrations between 60 and 120 mg% (3.3 to 6.6 mM/L).
Our food also has the sugar fructose (as the name suggests, it is sugar of fruit), and galactose (in milk). The 3 monosaccharides are glucose, fructose, and galactose.
Food sugars of 2 each monosaccharides are disaccharides (“di” = Greek “two”; also referred to as refined sugars because they are made by refining bamboo or beets for sugar content).
Sucrose table sugar is the disaccharide made of a molecule each of glucose and fructose. Maltose sugar of plant stems is disaccharide of 2 linked glucose, and lactose sugar of milk is disaccharide of glucose and galactose.
The most common food carbohydrate, starch, is composed of very large molecules, each molecule of starch consisting of 100’s of monosaccharide sugars. This carbohydrate is called “polysaccharide” (“poly-” is the prefix for many, in English, multi-). Starches differ from each other in the number of monosaccharides, in the branching in the molecule, and in the kind of chemical bonding.
The purpose of starches is storage of the energy in food. In humans, the equivalent of starch is glycogen, which is formed and stored in the liver, muscle, and brain when an excess of glucose gets produced from the diet. Glycogen allows us to go without food for days as a source of internal energy by getting reconverted into glucose and burned as fuel.
We eat the polysaccharides in the starch of bread or rice and they get digested quickly in mouth and stomach to the disaccharide sugars, and then to fructose, galactose (from milk) and glucose, and these 3 monosaccharides are absorbed into blood and transported to liver, where the galactose and fructose are converted to glucose, the final carbohydrate fuel unit. Of course, we may also eat di- and mono-saccharides directly with the same final effect to convert to glucose in the liver.
Carbohydrate is the original food substance. Plants form it from air and water, using sun’s energy plus chlorophyll in green leaf. An animal cannot make it from simpler molecules. Most calories we need to move and much of our structural substance comes from the body’s conversion of glucose into energy or into other chemical compounds. So an animal must eat plants or must eat other animals that eat plants to continue to live. From glucose, many other nutrients are made by living things. Many living forms live purely on the carbohydrates, which are closest to a universal food.
Finally, the concept of refined vs. natural sugars is erroneous. The refined sugars (sucrose, maltose, and lactose) are disaccharides that are simply a stage in the digestion of our main carbohydrate food source, bread or rice, or in the metabolism of their formation. They are not in themselves harmful or less healthy than eating so-called natural sugars, which are the monosaccharides, glucose, galactose (in milk) or fructose (in fruits).
What are the Physician’s Notebooks?
Physician’s Notebooks is a blog that teaches Healthy Longevity, which means living past age 80 on one’s feet with wit and wits. Reading and rereading should bring success and happiness. It may up your IQ, SAT, TOEFL (Test of English as a Foreign Language) and MCAT scores.