Structure of Sugar
Sugar is a carbohydrate that occurs naturally in every fruit and vegetable in the plant kingdom. It is the major product of photosynthesis, the process by which plants transform the sugar energy into food. Actually carbohydrate is of 3 types:
- Simple Sugar(Sugar)
Further, simple sugar is 2 type: Single Sugar or Monosaccharide and Double Sugar or Disaccharide. They are further divided into various types. Please look at the chart below to understand the structure of Sugar:
Single Sugar contains one type of sugar molecule & Double sugar contains two types of single sugar molecule. Like: Sucrose is formed by combination of glucose & fructose.
Sucrose = Glucose + Fructose
Maltose = Glucose + Glucose
Lactose = Glucose + Galactose
What is Glucose, Fructose, Sucrose, Maltose, Lactose..?
Glucose is the most important simple sugar in human metabolism. It is the main energy source for plants, animals and also humans. It is found in the human bloodstream where it is referred to as “blood sugar”. The normal concentration of glucose in the blood is about 0.1%, but it becomes much higher in persons suffering from diabetes.
The energy yield is about 686 kilo calories per mole which can be used to do work or help keep the body warm. It requires no digestion and is often provided intravenously to persons in hospitals as a nutrient.
Fructose is almost similar to Glucose as it is also simple sugar. When it enters the body, fructose also eventually make their way to the liver to be metabolized. Fructose does not often occur alone in nature, but is typically found in combination with glucose or sucrose in fruits and vegetables, including honey, oranges, berries, sweet potatoes and onions
Difference between Glucose & Fructose
Although glucose & fructose are similar in many ways but still they are different:
1. Insulin Production
Glucose is eaten, absorbed into the blood stream, and makes it way to the liver where it is broken down to supply energy to the entire body. This breaking down process requires pancreas to secrete insulin. However, fructose is eaten and absorbed but does not stimulate the release of insulin, as our pancreas does not possess cellular receptors that respond to fructose therefore is a marginally better choice for diabetics.
Glucose is used by our body for energy. Nearly all our cells can split glucose to produce high-energy molecules. Conversely, fructose is metabolized almost exclusively by your liver, where it is either stored as glycogen for future energy needs or converted to triglycerides.
Raw fructose is many times sweeter than glucose.
Sucrose is a disaccharide, meaning it contains two simple sugars, composed of one molecule of glucose bound to one molecule of fructose linked together in a long chain at a ratio of 1:1. Sucrose is table sugar and is sold as raw sugar, granulated sugar, confectioner’s sugar and brown sugar, which is an unrefined sugar made from sugar cane juice.
When we eat food rich in sucrose, it makes way through digestive tract and reach the stomach and than to small intestine where it breaks down into glucose & fructose so it can be absorbed through the small intestines into the bloodstream.
Maltose, also referred to as malt sugar, is the least common disaccharide consisting of two glucose molecules. Although maltose is not as sweet as sucrose it is still used as a sweetener. It is most commonly found in germinating grain, barley malt, brown rice syrup and occasionally corn syrup.
During digestion, maltase is responsible for metabolizing maltose and breaking it down into two alpha glucose molecules. These glucose molecules are then absorbed by the body to be used for energy. If the body cannot break down maltose, diarrhea and excessive gas can occur.
Lactose is a disaccharide, meaning it contains two simple sugars, composed of one molecule of glucose bound to one molecule of galactose. Lactose occurs naturally in both human and cow’s milk.
Which is better Glucose or Fructose?
The fructose vs. glucose debate first made headlines in 2009. Researchers from the University of California Davis found that when subjects were given 25% of their daily calorie requirements as a fructose or glucose drink for 10 weeks, both groups gained weight, but it was the fructose group that gained a significant amount of unhealthy, visceral abdominal fat which is associated with risk of type2 diabetes & cardiovascular disease. The fructose group also had increased fasting blood sugar, cholesterol levels and insulin resistance, while the glucose group did not.
It is nearly impossible, however, to find pure fructose or glucose in the foods we eat. Despite its name, high-fructose corn syrup contains about 42-55% fructose (though there is some that contains more), making it quite similar to table sugar, or sucrose, which is 50% fructose and 50% glucose.
Although fructose loosely translates to “fruit sugar,” almost all fruits are a mix of fructose, glucose and sucrose, and in far lower amounts than what is found in most processed foods. Agave nectar, which has been gaining popularity as an alternative sweetener, is actually mostly fructose, with some brands containing up to 92%.
Disadvantages of Eating Sugar
Sugary foods make up a large part of the average diet because they taste good. Sugar is added to many foods to boost the flavour, preserve the shelf life and achieve a desired texture. Because most foods have some form of sugar in them, it is nearly impossible to eat a totally sugar-free diet. However, it is definitely possible to cut out the unnatural, bad forms of sugar, which are found in processed foods, soft drinks, desserts, and other sweet treats. Excess sugar consumption can lead to following conditions:
- Weight Gain
- Tooth Decay
- Heart disease risk factors like high blood pressure, high blood cholesterol levels.
- Yeast infection such as Candida.
- Other Health Problems
- Sugar provides calories, but has no inherent nutritional value. Glucose is considered the healthiest sugar because it is what the body uses for fuel, but glucose by itself is not used as a sweetener in processed foods. It is generally used attached to sucrose, or more often attached to fructose to form high-fructose corn syrup. Ingesting large amounts of high-fructose corn syrup has been shown to lead to an increased risk of becoming obese and developing heart disease and diabetes.
- Check the package labels for nutritional content to know what sugars are contained in the foods you eat. Package labels usually list ingredients by their common names. For example, sucrose will be listed as sugar , glucose can appear as dextrose and fructose as corn syrup or high-fructose corn syrup.