Dr Hector Perera     London

There are many kinds of sugars but we often come across mainly two kinds of sugars that are table sugar and fructose. There are good and bad sides of these kinds of sugars and sometimes people just eat them without due care.

 The table or granulated sugar most customarily used as food is sucrose, a disaccharide (in the body, sucrose hydrolyses into fructose and glucose. Glucose, or commonly called sugar, is an important energy source that is needed by all the cells and organs of our bodies. Some examples are our muscles and our brain. Where does it come from? Glucose or sugar comes from the food we eat for example; carbohydrates such as fruit, bread, pasta, rice and cereals are common sources of glucose. These foods are broken down into sugar in our stomachs, and then absorbed into the bloodstream.

The body’s digestive system, using bile and enzymes, breaks down the starch and sugar in these foods into glucose. This functional form of energy then gets absorbed through the small intestine into the bloodstream. It is then carried throughout the body, providing energy for the person to perform all types of activities, such as simple movements, demanding physical exercises or even thinking.

Every cell in the body can use glucose for energy. If we don’t get glucose from the diet, our bodies produce what we need out of proteins and fats.

Fructose, however, is very different.

This molecule is not a natural part of metabolism and humans do not produce it. Fructose, or fruit sugar, is a simple monosaccharide found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose that are absorbed directly into the bloodstream during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847.

Pure, dry fructose is a very sweet, white, odourless, crystalline solid and is the most water-soluble of all the sugars. From plant sources, fructose is found in honey, tree and vine fruits, flowers, berries, and most root vegetables.

Commercially, fructose is frequently derived from sugar cane, sugar beets, and maize. Crystalline fructose is the monosaccharide, dried, ground, and of high purity. High-fructose corn syrup (HFCS) is a mixture of glucose and fructose as monosaccharides. In fact, very few cells in the body can make use of fructose except liver cells. When we eat a lot of sugar, most of the fructose gets metabolized by the liver. There it gets turned into fat, which is then secreted into the blood.

Dr. Robert Lustig, Professor of Paediatrics said, “Fructose is Sweet, But Dangerous”

Fructose is a monosaccharide (simple sugar), which the body can use for energy. Because it does not cause blood sugar rise tremendously (has a low glycemic index), it was once thought that fructose was a good substitute for sucrose (table sugar). However, the American Diabetes Association and nutritional experts have changed their minds about this.

 Is fructose bad for me?

A small amount of fructose, such as the amount found in most vegetables and fruits, is not a bad thing. In fact, there is evidence that a little bit may help your body process glucose properly. However, consuming too much fructose at once seems to overwhelm the body’s capacity to process it. The diets of our ancestors contained only very small amounts of fructose. These days, estimates are that about 10% of the modern diet comes from fructose.

 What happens if I consume too much fructose?

Most of the carbohydrates we eat are made up of chains of glucose. When glucose enters the bloodstream, the body releases insulin to help regulate it.

Fructose, on the other hand, is processed in the liver. To greatly simplify the situation, when too much fructose enters the liver, the liver can’t process it all fast enough for the body to use as sugar. Instead, it starts making fats from the fructose and sending them off into the bloodstream as triglycerides.

What is a triglyceride?

A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of vegetable oil (typically more unsaturated) and animal fats (typically more saturated).Triglycerides are a major component of human skin oils. Triglycerides are formed by combining a molecule of glycerol with three molecules of fatty acids. That is because Glycerol has three OH groups and sometimes it is called a trihydric alcohol. Fatty acids have a COOH group then three molecules of fatty acids combine with the three OH groups on a single Glycerol molecule to form an ester for which we call a triglyceride.

We are familiar with the ester smell such as found in “ach-charu” one kind of pickle made by adding vinegar and red onions and green chillies. The special sweet smell that comes out of “ach-charu” is the smell of that ester. The body sprays give a sweet smell due to its esters so the word ester is quite familiar in day today work.

Why too much triglycerides are bad?

This is potentially bad for at least for few reasons: High blood triglycerides are a risk factor for heart disease.

Fructose ends up circumventing the normal appetite signalling system, so appetite-regulating hormones aren’t triggered and you’re left feeling unsatisfied. This is probably at least part of the reason why excess fructose consumption is associated with weight gain or a reason for obesity.

There is growing evidence that excess fructose consumption may facilitate insulin resistance, and eventually Type 2 Diabetes. However, some of this effect may be from chemicals in soda which reacts with the high fructose corn syrup.

 What are the major sources of fructose?

     Fruits and vegetables have relatively small, “normal” amounts of fructose that most bodies can handle quite well. The problem comes with added sugars in the modern diet, the volume of which has grown rapidly in recent decades. The blame has often been pinned to high fructose corn syrup (HFCS), which manufacturers say is made up of 55% fructose and 45% glucose. In truth, the exact proportions have been revealed in testing to be somewhat variable. For example, this study revealed an average of 59% fructose in HFCS, with some major brands of soda containing 65% fructose. High fructose corn syrup has become incredibly inexpensive and abundant, partially due to corn subsidies in the United States. So many argue that the problem is that it has become so cheap that it has crept its way into a great number of the foods we eat every day. Is corn syrup fructose different than fructose found in other foods?

 Which foods have high fructose corn syrup and other sugars?

Today, almost all packaged foods have sugar added in some form, which almost always includes a lot of fructose. Honey has about the same fructose/glucose ratio as high fructose corn syrup. Fruit juice concentrates, sometimes used as “healthy sweeteners,” usually have quite a lot of fructose (never mind that the processing of these concentrates strips away most of their nutritional value). Agave syrup is up to 90% fructose. Look at the ingredients on packaged food labels and you will probably see sources of fructose.

According to National Health Service [NHS] the symptoms of hypoglycaemia usually begin when a person’s blood glucose level drops to somewhere between 3 and 4 millimoles (mmol) per litre. This can be easily checked at home with a small hand held machine. Sometimes the doctors’ advice these diabetic patients to check the blood sugar level at home on a regular basis such as once a day or twice a day. It is very important to consult their doctor about this subject.

If you have diabetes, particularly if it’s treated with insulin, you may be advised to use a small device called a blood glucose meter to check your blood glucose levels regularly.

The symptoms may vary from person to person and it is important to be aware of the early warning signs so that you can treat them.

Symptoms and signs of hypoglycaemia can include some of these symptoms: feeling hungry, sweating, dizziness, tiredness (fatigue), blurred vision, trembling or shakiness, going pale, fast pulse or palpitations, tingling lips, irritability, difficulty concentrating, confusion, disorderly or irrational behaviour, which may be mistaken for drunkenness.

This shows sucrose or table sugar is more important than fructose. Everybody must get some food on a regular daily basis to meet with the body’s sucrose requirements otherwise some people suffering from diabetics might get into hypoglycaemia, so need to be careful about some food. On the other hand, if too much sugar or sugary drinks are consumed, the people who has diabetic might get into a situation called hyperglycemias. This is also an absolutely dangerous situation. It is important not to exceed the limit. Your comments are welcomed perera6@hotmail.co.uk