As the main ingredient in candy, sugar is what Halloween is all about. White gold for candy companies and pure joy for kids of all ages, sugar keeps dentists in business.
Sugars are made from three monosaccharide primary derivatives— glucose, fructose, and galactose. Depending on how they are linked, these molecules have the potential to make large, intricate polysaccharide compounds. The molecule that we call sugar is made up of equal parts glucose and fructose, forming a disaccharide referred to as sucrose, or table sugar (C12H22O11).
A naturally occurring compound, sucrose is a carbohydrate that occurs naturally in every fruit and vegetable as a major product of photosynthesis. Plants absorb sunlight and use that energy to extract carbon from the carbon dioxide present in the atmosphere. These captured carbon atoms are combined with hydrogen and oxygen (derived from water) to create fructose and glucose. To store these compounds for a longer period of time, plants convert them to sucrose. Interestingly, sugar cane and sugar beet are the only two plants that make enough sucrose to be commercially viable. Refineries—such as the former Redpath sugar plant located on Toronto’s waterfront—purify and concentrate raw sugar to the solid, crystallized form that we know and love.
In 1953, while working in the National Research Council’s lab at the University of Saskatchewan, Dr. Raymond Lemieux became the first scientist to synthetically produce table sugar from its components. Tests for blood types, new vaccines, and other medical advances are attributed to his discovery, which was critical, as the scientific understanding of sugars was limited at the time he began his research.
By determining the three-dimensional structure of sugar molecules and understanding their chemical properties, scientists found the configuration by which fructose and glucose combine to form sucrose. From Lemieux’s work stemmed further discoveries on how sugar is utilized in the human body, such as the finding that the shape of sugar molecules on the surface of blood cells determines what blood type we have.
Oligosaccharides—otherwise known as simple sugars—are also found on the surface of organs and tissues. Sugar molecules differ from one body to the next, so rejection of a transplanted organ is likely if the recipient’s body recognizes the differently- shaped molecules from the donor’s body as a foreign object. The transplanted organ can be destroyed within hours, possibly minutes. The shape of sugars affects their function, and by studying the structure of oligosaccharides, Lemieux and other chemists have been able to create antigens that promote the integration of transplanted organs.
Sugar is the fuel that powers life, including us humans. In mammals, the stomach readily digests sucrose then transfers the broken-down products into the bloodstream. People with defects in glucose metabolism may not be able to cope with this rapid rise of blood sugar. An imbalance in blood sugar levels can lead to chronic diseases that are potentially fatal.
A greater than average level of glucose in the bloodstream is referred to as hyperglycemia, commonly caused by a deficiency of insulin, type I and II diabetes, excessive food intake or defects in the pancreas. The opposite of this condition, lower levels of glucose, is known as hypoglycemia and be caused by insufficient sugar intake, an overactive metabolic system or too much insulin, which can make a person hungry, irritable, and tired.
For a balanced diet, sugar should be consumed in moderation. Cavities are a common adverse effect if sugar is consumed in large quantities. Bacteria in the mouth use sugars as energy, leaving an acidic by-product that deteriorates tooth enamel, making teeth more susceptible to decay. Sucrose has an extremely high energy content— 17 kilojoules per gram—which may sound beneficial, but will displace other necessary nutrients and could lead to obesity and insulin resistance.
As with so many things concerning the food we eat, moderation is key. Sometimes, the best things in life aren’t sweet.
