What is sugar? Surely we all know what sugar is! It is that crystallised, white, sweet stuff that most of us add to our tea and coffee. We make cakes and biscuits with it; it is what lollies are made of and it tastes so good. Sometimes it is a golden colour and other times it is a dark brown hue. But sugar is more than this. So much, much more.
At its most simple, sugar is a tiny molecule made up of carbon, hydrogen and oxygen atoms. Sugar, as we know it is, in fact, two of these molecules joined together and called sucrose (all sugars end with “ose”). The two molecules of sucrose (table sugar) are glucose and fructose. The body needs and uses glucose for all its energy requirements.
But before you rush out and buy that jumbo-size bag of jelly beans, saying “I need this for energy”, remember that the body is so clever that it converts anything you eat to glucose to fuel its energy demands – including proteins and fats.
Carbon, hydrogen and oxygen are all present in glucose, fructose and sucrose but arranged differently.
So that has answered the basic “what is sugar” question, but what we should really be asking is “what are sugars”? Sugars are substances that have the building blocks of carbon, hydrogen and oxygen. They are always made up of these elements, but can be arranged differently in the way they join and the number of each of these atoms.
This determines what types of sugar they are. You may have heard of lactose (sugar in milk), maltose (sugar in beer), galactose (a part of lactose), glucose (in carbohydrates) and fructose (found in fruit). Some sugars that you may not have heard of might include ribose, arabinose, xylose, mannose and talose. Yes, these are all sugars and appear somewhere in the food chain.
The reaction when a glucose and a fructose molecule join together to form sucrose is called a condensation reaction. A by-product of the joining is one molecule of water H2O – 2 hydrogens and one oxygen. Water is removed and a bond is made. This water molecule floats around until it is needed to either split the glucose/frustose bond again or another molecule may need it to create a bond with it. Or the H2O molecule can be split up and the hydrogen and oxygen used somewhere else.
Once glucose and fructose have joined together as sucrose we perceive them as being 'sugar', even though fructose has little nutritional value and is largely responsible for deposits of fat in our bodies.
A molecule of sugar, made up of the carbon, hydrogen and oxygen atoms, is known as a mono-saccharide, meaning one sugar. An example of this is glucose or fructose. Two molecules are known as di-saccharide – sucrose.
As the molecules build up to ten molecules they are called oligo-saccharides and are known as complex sugars. Once ten molecules are joined together they are called poly-saccharides or complex sugars and include starch and cellulose, taking the form of vegetables and grains.
Simple sugars are easy for the body to digest as they only have one or two carbon bonds to break in order to release the energy for your body to use. This is OK if you need a burst of energy quickly – a bit like speeding through a traffic light before it goes red. However complex carbohydrates are a much better source of fuel as it takes longer to break the bonds between the atoms thereby creating a slower energy release – for the 600 mile road trip – nice and steady.
This video might open your eyes to hidden sugars in your every-day supermarket shopping:
So there you have it – “what is sugar” now takes on a whole new perspective!