Sugar comes in many forms. fructose and glucose are monosaccharides, known as simple sugars. Glucose is the primary sugar in the blood, and fructose is the primary sugar in fruit and high fructose corn syrup. The simple sugars can combine to form more complex sugars, like the disaccharide sucrose (table sugar), which is half glucose and half fructose. Other forms of sugar are maltose (malt sugar) and lactose (milk sugar). Chemical terms ending in -ose indicate a sugar.

However, all sugars are not equal. The main difference between them is how your body metabolizes them. Glucose is the form of energy that our bodies run on - it is a simple, usable form of sugar. However, we are now consuming more and more sucrose and fructose in massive quantities, which is the primary cause for rising obesity levels, diabetes, a factor in the development of other chronic diseases, and is damaging to health in general.

Here are 10 reasons to cut down on, or avoid completely this harmful substance:

1. Most concentrated forms of sugar (white sugar, brown sugar, malt, syrup) are devoid of vitamins and minerals, unlike natural sources such as fruit. White sugar has around 90% of its vitamins and minerals removed. Without vitamins and minerals, our metabolism becomes inefficient, contributing to poor energy levels, concentration and weight control.

2. Sugar actually uses up the body's stores of vitamins and minerals whilst providing next to none. Each teaspoon of sugar uses up B vitamins, for example, which can result in a deficiency. B vitamins are vitamin for maximizing mental performance. Around 98 % of the chromium present in sugar cane is lost turning it into sugar. This mineral is vital for keeping blood sugar levels stable.

3. Sugar, in its concentrated, refined form, cannot be digested. It inactivates digestive enzymes and remains in the tract, fermenting and causing the blood to become acidic. One effect of an over-acidic digestive tract is that the good bacteria in the intestine are destroyed. These are required in the final stages of digestion and without them, rotting and stagnation of food is promoted, instead of digestion. The half-digested carbohydrates leak into the bloodstream and cause problems in the joints, muscles and organs, and have been linked to diseases such as osteoarthritis, kidney disease, irritable bowel syndrome, candida, reflux/heartburn and chronic allergies.

4. An excess of sugar sends adrenalin, the stress hormone, sky high. In a study from Yale University, 25 children were given a drink containing the amount of sugar found in a can of a popular soft drink. The rebound sugar drop - when too much sugar in the blood causes insulin to overcompensate by taking too much sugar out - boosted their adrenalin to over five times their normal level. Most of the children had difficulty concentrating and were irritable and anxious, which are normal reactions to too much adrenalin in the bloodstream. Jones TW, Borg WP, Boulware SD, McCarthy G, Sherwin RS, Tamborlane WV. Enhanced adrenomedullary response and increased susceptibility to neuroglycopenia: mechanisms underlying the adverse effects of sugar ingestion in healthy children. J Pediatr. 1995 Feb;126(2):171-7.

5. Conclusive evidence has found that high sugar consumption is linked to poor mental health. Research has found that the higher the intake of refined carbohydrates, the lower the IQ. If fact, the difference between high sugar consumers and low sugar consumers was a staggering 25 points.

6. Sugar is also implicated in aggressive behavior, anxiety, hyperactivity and attention deficit, depression, eating disorders, fatigue, learning difficulties and premenstrual syndrome.

7. Glucose damages the brain. Glucose itself is not toxic, but when blood sugar levels go above the maximum threshold, which it what happens in severe diabetes (dysglycaemia), glucose becomes toxic to the brain. This is why diabetics develop nerve, eye and brain damage. An excess of glucose, much like oxidants, damage nerve cells and stop them working properly. This reaction, called glycation, causes the proteins in the brain and nervous system to react, slowing down brain communication, and causing inflammation in the brain.

8. The body can become "sensitized" to sugar. The more sugar is consumed, the more effective the body is in absorbing it; and the more that is absorbed, the more damage it will do. This is because sugar activates its own metabolic pathways in the body, which become "upregulated", or increased in sensitivity to sugar.

   The good news is that even a short break from sugar will cause sugar sensitization to rapidly decrease and "downregulate" those metabolic pathways. Research indicates that even two weeks without consuming sugar will cause your body to be less reactive to it.

9. Sugar is the cause of bone loss and dental decay. It causes an increase in calcium levels and a drop in phosphorus levels, because calcium is pulled from the teeth and bones. This drop in phosphorus hinders the absorption of calcium, making it unstable and therefore toxic. Thus, sugar consumption causes tooth decay not because it promotes bacterial growth in the mouth, but because it alters the internal body chemistry.

10. Other refined carbohydrates such as white bread, white rice and processed cereals have an effect similar to that of refined sugar. The process of refining or even cooking starts to break down complex carbohydrates into simple carbohydrates, in effect predigesting them. When eaten, they produce a rapid increase in blood sugar level and a corresponding surge in energy. The surge, however, is followed by a drop as the body scrambles to balance blood sugar levels.

Here is the link for an excellent video by Dr Robert Lustig, on the damage caused by sugary foods (please note, there is a musical introduction for a minute at the beginning and around 40 seconds at the end):

http://www.youtube.com/watch?v=dBnniua6-oM

Robert H. Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology, explores the damage caused by sugary foods. He argues that fructose (too much) and fiber (not enough) appear to be cornerstones of the obesity epidemic through their effects on insulin. Series: UCSF Mini Medical School for the Public [7/2009] [Health and Medicine] [Show ID: 16717]