Sugar. It is without a doubt something that takes the edge off, it gives us comfort and provides us with energy. It is found in much of what we eat and yet modern research is suggesting it is toxic to the human body and may even be considered a drug. It is linked to physical symptoms related to diabetes, heart disease and obesity and many mentally sited symptoms such as memory loss and addiction.
Humans have not always eaten sugar apart from what is naturally contained in foods such as fruits and grains, and certainly they have not eaten it in the quantities now consumed world wide. At the end of the medieval period, table sugar was considered a “fine spice” and was still very expensive. Around 1500, technological improvements and more convenient sources meant sugar became a cheaper bulk commodity. Beginning in the late 18th century, the production of sugar was increasingly mechanized which reduced the fuel required and the amount of sugar lost in the process eventually making sugar affordable to the masses. High-fructose corn syrup was first developed in 1957. It can be six times sweeter than table sugar and was added to many processed foods and drinks in the United States from around 1975 to 1985. It is now added to processed foods as a sweetener or preservative.
Different types of sugars
Not all sugars are metabolized the same way in our body. Glucose is the preferred energy source. We process most carbohydrates into glucose, either to use immediately for energy or to store in muscle cells or the liver as glycogen. Our glucose levels signal that insulin is to be secreted to facilitate the entry of the glucose into cells. Fructose is found naturally in many fruits and vegetables but is not metabolized in all cells but only in the liver. Unlike glucose, it does not cause insulin to be released or to stimulate the production of leptin, a key hormone for regulating energy intake and energy expenditure.
Sucrose, or table sugar, is made from sugar cane or sugar beets and some fruits and vegetables naturally contain it. Sucrose contains one molecule of fructose and one molecule of glucose. After it is broken down in the body, both sugars are taken up by their specific transport mechanisms as described above. The body responds to the glucose in its usual manner and uses it as its main energy source. The excess energy from the fructose, if not required, will be transferred into fat synthesis. High-fructose corn syrup contains from 55% to 90% fructose, the rest is glucose and possibly other sugars.
Current science argues that each of these sugars eventually ends up as glucose and fructose in our guts, and because our bodies react the same way to both, and the physiological effects are identical no one form of sugar is more deleterious than another.
So what is the problem?
Robert Lustig, an American pediatric endocrinologist, argues that the way the human body metabolizes fructose makes it singularly harmful, especially if consumed in large quantities. The calories are the same, the taste is the same, but the metabolic consequences are quite different.
The glucose from sugar and starches, such as an apple, is metabolized by every cell in the body because every cell readily converts glucose into energy while the fructose component of sugar, from say a soda drink with ‘empty’ calories, is metabolized primarily by the liver turning it into useable glucose and lactate. This means the soda is more work for the liver. A super sized soda is even more problematic, since the speed with which the liver has to do its work will also affect how it metabolizes fructose and glucose. If fructose hits the liver in large quantity and with high speed, the liver will convert much of it to fat. This may lead the way to insulin resistance, obesity, heart disease, certain cancers and many other possible health problems.
Insulin resistance is basically a metabolic syndrome when the cells in the body are actively ignoring the action of the hormone insulin. We secrete insulin when we eat food, especially carbohydrates, to regulate blood sugar levels. When the cells become resistant to insulin, the pancreas responds by pumping out more and more insulin. Eventually the pancreas will no longer keep up with the demand and the blood sugar will rise out of control.
Life without the liver
The liver is one of the organs necessary for survival and although the organ’s total number of functions vary, most textbooks generally put it at around 500 or so.
Since fructose taxes the liver, it may not have much energy left for all its other functions. One consequence of this energy depletion is the production of uric acid linked to gout, kidney stones and high blood pressure. Lustig suggests the harm is really in the amounts and not that sugar itself is harmful. By the early 2000s the U.S.D.A. findings suggest the average American consumes between 75 and 90 pounds per year beyond what they might naturally consume in fruits and vegetables. The suggested healthy range would be 40 pounds of ‘added sugars.’
Another major issue is the need for fiber to metabolize sugar. Processed foods are made by removing fiber and adding sugars. The removal of fiber is damaging because it reduces the time it takes for food to become a usable form of glucose for the body. Insulin stimulates the liver and muscle cells to store glucose. Processed foods tax beta cells by boosting them to produce insulin faster.
There is also the effect of a weakened liver on the brain. The relationship between these two organs has been known for many years. Patients typically present early with liver disease or later with neurological syndrome which consists of various subtle neuropsychiatric symptoms such as a change in behaviour or performance at school and abnormality of movement.
Is sugar a drug?
I don’t know many people who have cut sugar cold turkey for more than a month. If you have ever tried it, you may have found it nearly impossible. The fact that some people can’t actually stop eating it if they seriously tried would suggest that sugar is addictive.
Nicole M. Avena, Pedro Rada, and Bartley G. Hoebel published the results of a such a study in 2008. “Addiction” implies psychological dependence and is therefore a mental or cognitive problem, not just a physical ailment. Drug dependence is characterized by compulsive, sometimes uncontrollable, behaviors that occur at the expense of other activities and intensify with repeated access. After a month of specialized sugar feeding schedule, rats exhibited a series of behaviors similar to the effects of drugs of abuse categorized as “bingeing” (unusually large bouts of intake), opiate-like “withdrawal” (indicated by signs of anxiety and behavioral depression), “craving” (measured during sugar abstinence as enhanced responding for sugar) and “behavioral sensitization” (increased locomotion in response to repeated administrations of a drug). These four categories of behaviour are similar to those observed with the abuse of drugs.
Chemically, sugar has a powerful affect on the reward centers of the brain. After we consume food with a lot of sugar, a massive amount of dopamine is released in the Nucleus accumbens in the brain. However, if we eat sugary food often, the dopamine receptors start to down-regulate which means there are fewer receptors for the dopamine. Similar to the experience with drugs such as nicotine and cocaine, the next time we eat a sweet food, the previous effect is blunted so we would need to consume more sugar to achieve the same feeling. Comparable to any type of addiction, there can be anatomical changes in the brain and this can lead to a full-blown addiction to sugar.
If we pay attention we may also notice withdrawal symptoms when sugar is completely removed from the diet such as headaches, mood swings and lethargy. This can happen with many types of foods and drugs and can correspond to an allergy or sensitivity to the food or drug as much as an addiction.
Sugar tricks the mind
As we eat, the human body strictly regulates the amount of glucose in the blood. Glucose stimulates the pancreas to secrete the hormone insulin, which helps remove excess glucose from blood, and bolsters production of the hormone leptin, which suppresses hunger. Fructose does not trigger insulin production and appears to raise levels of the hormone grehlin, which keeps us hungry. Some researchers have suggested that large amounts of fructose encourage people to eat more than they actually need. In studies with animals and people by Kimber Stanhope and other researchers of the University of California Davis, excess fructose consumption has increased fat production, especially in the liver, and raised levels of circulating triglycerides, which are a risk factor for clogged arteries and cardiovascular disease. Some research has linked a fatty liver to insulin resistance, a condition that exhausts the pancreas until it loses the ability to properly regulate blood glucose levels.
Fiber also helps in curbing sugar intake. It alerts your mind that you’ve consumed calories and you don’t need to eat anymore which fructose and processed foods devoid of fiber won’t do. We need fiber and fructose to work together. “Fructose makes up for fiber’s lack of sweetness while fiber makes up for fructose’s uselessness.”
The brain on sugar
Having memory problems? It is a total misnomer that the brain requires glucose as a fuel. It actually functions better burning other fuels such as ketones, substances that are made when the body breaks down fat for energy. Dr. Ron Rosedale suggests that Alzheimer’s and other brain disorders may be caused by the constant burning of glucose for fuel by the brain. In early 2005, Alzheimer’s was tentatively dubbed “type 3 diabetes” when researchers discovered that, as well as the pancreas, the brain also produces insulin, and this insulin is necessary for the survival of brain cells.
A study by Gomez-Pinilla, a member of UCLA’s Brain Research Institute, found that rats’ memory deficits were triggered by an onset of insulin resistance caused by their prolonged high intake of fructose solution. This in turn damaged their synapses, the connections between brain cells that enable learning. This dysfunction was mitigated and memory improved when a second group of fructose rats were also given omega-3 fatty acids in the form of flaxseed oil and docosahexaenoic acid (DHA), which protected against such damage. Rats that did not receive omega-3s and drank regular water instead of fructose also did better than the ones that were given only glucose as their drinking option.
I once did a three month sugar fast, which meant the removal of all sugars not coming from basic foods. This meant no added sugars, no fruits and sweet vegetables, no ingredients ending in ‘ose,’ no hidden sugars such as citric acid and basically removing 99% of all processed foods from my diet. This short regime changed my life, my mind and my body but it was one of the hardest things I have accomplished. I dare you to try it and tell me sugar is not addictive!
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