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Sweet Inflammation: How Sugar Leads to Chronic Disease
Consumers are sometimes unclear as to exactly what sugar is, and modern food labeling practices completely justify this confusion. The Nutrition Facts label required on most packaged foods and beverages lists the total amount of “sugars” in the product. Sugars here can mean any caloric substances that sweeten the food, whether naturally occurring or added in processing. For the purposes of the ingredients list, however, sugar can only mean sucrose (table sugar), a refined sweetener made from sugar cane or sugar beets – the very first refined sweetener to hit the market.
Health writers and the public tend to use a broad definition of the term, similar to the one used on the Nutrition Facts label. For example, even though most processed foods contain high fructose corn syrup (HFCS) or similar manmade sweeteners, which are identified individually on the ingredients list, people generally refer to all of these as “added sugar.” This is reminiscent of the basic biological definition that a sugar is any one of many generally similar naturally occurring carbohydrates that serve as structural components in living cells, and sources of energy for many organisms.
In biochemistry, most sugars receive -ose suffixes – e.g., lactose (found in milk and dairy products), fructose (found in fruit and certain other plants), and glucose or dextrose (found in blood and plant sap). However, in the marketplace, sweeteners go by myriad names, such as honey, barley malt syrup, fruit juice concentrate, rice syrup, date sugar, and agave nectar. Despite the wide variety of terms, all of these products have certain similarities, both in their structure and in how they function in the human body.
The structure of sugars
Each of these sweeteners is composed of one or more simple sugars, or monosaccharides – predominantly, fructose and glucose. These simple sugars link together to form compound sugar molecules, such as maltose (found in germinating grains) or sucrose. Sucrose contains a roughly equal mix of fructose and glucose. Manmade products such as HFCS (made from corn syrup) and crystalline fructose (derived from corn or sucrose) are manufactured using enzymatic processing to increase the level of fructose. Agave nectar is naturally high in fructose, and some producers may cook out much of what little glucose exists, resulting in a 95 percent fructose blend.
This is significant because glucose and fructose are metabolized differently in the body. When blood sugar levels rise after consumption of glucose, the pancreas releases insulin, which removes the excess glucose from the blood and carries it to the cells, where it is used for energy. Fructose consumption does not stimulate the release of insulin. Instead, fructose is metabolized into glycogen, a secondary fuel source, by the liver. When there is too much fructose for the liver to process, the organ turns the sugar into fat for storage. Excess fructose in the bloodstream has other problematic effects, including raising low-density lipoprotein (LDL) and triglyceride levels. However, when there is insufficient glucose, the body can convert fructose, as well as starch, protein, and a component of fat, into glucose for use as fuel.
Although HFCS usually contains only a slightly higher fructose-to-glucose ratio than sucrose, there are additional considerations. In naturally occurring sugars, such as sucrose, the fructose and glucose bind together using enzymes that aren’t present in the manmade, fructose-heavy products. In HFCS, the glucose and fructose are separate monosaccharides and are processed separately in the body. Sucrose, in contrast, is a disaccharide in which fructose binds to glucose to temporarily form a new molecule. It must be hydrolyzed (decomposed in water) before being absorbed in the intestines. This suggests that eating sucrose is preferable because the delay in absorption could result in a lower concentration of fructose in the blood after consuming table sugar than after consuming similar amounts of HFCS or any other manmade fructose sweetener.
Despite their differences, most sugars tend to upset the body chemistry and interfere with the state of homeostasis. The body wants to maintain a precise balance of elements: glucose, vitamins, minerals, amino acids, fats, and so forth. Homeostasis is such a high priority that many other considerations will be disregarded in order to maintain it. For example, the body will pull alkaline calcium from bones to counteract an overly acidic state, which can be caused by an excess of sugar in the bloodstream. Eating sugar changes the mineral relationships in the body, and this can cause mineral-dependent digestive enzymes to fail. Undigested food can then leak into the bloodstream, where it is perceived as a foreign invader and provokes an immune response that includes inflammation. Doctors call this condition gut permeability or leaky gut syndrome. Interestingly, at the same time as it provokes an immune response, sugar consumption suppresses the immune system, sapping the body’s ability to protect itself from disease-causing microbes or other dangers.
Acute vs. chronic inflammation
Inflammation is part of the body’s immune response to various kinds of threats. If you slam your fingers in a door, the swelling that generally results promotes healing of the injury. This is called acute inflammation, and it can be beneficial even if its symptoms make you feel miserable.
Like many things, however, too much inflammation is not good. If the immune system isn’t working at full efficiency, it may not be able to destroy all the perceived invaders. The body, sensing that the danger continues, keeps the inflammatory processes active, consuming energy at high rates. This is known as chronic inflammation, and it can lead to diseases including cancer, diabetes, heart disease, and Alzheimer’s. People with chronic inflammation don’t always show overt symptoms because the inflammation can be low grade and systemic. Suddenly, the person may get sick, seemingly out of the blue – but the illness may actually have been caused by years of silent damage to their tissues from inflammation.
To reduce the risks of chronic inflammation, doctors measure various inflammatory markers. One of these is C-reactive protein (CRP), an indicator of generalized inflammation in the blood. Another is advanced glycation end products (AGEs). A French chemist, Louis Maillard, experimented with burnt toast in 1912 and discovered these unique chemicals to be the result of a nonenzymatic binding of a sugar and a protein. This type of binding creates molecules for which the body has no digestive programming and which are automatically a source of inflammation. Over time, other researchers discovered that AGEs can form inside the body any time a lot of sugar and protein exist in the same place. Smoking tobacco also creates AGEs. Research has shown that AGEs are very pernicious, being nearly indestructible in a body that is out of homeostasis. Since fructose can occur as a relatively unstable molecule that reacts more easily with proteins than does glucose, the AGEs created with fructose would logically be more numerous and even tougher to get rid of than glucose-based AGEs.
Inflammation and disease
Today, many diseases are known to be associated with inflammation. The name we give the sickness – for example, asthma, heart disease, or cancer – simply depends upon which organ or tissue becomes inflamed. The risk of diseases such as diabetes, heart disease, and stroke is increased by the presence of metabolic syndrome, a collection of related conditions that includes high blood pressure, high blood glucose, insulin-resistance, low high-density lipoproteins (HDL), and high triglycerides. Many of these conditions can cause inflammation individually, and they certainly do so as a group. Obesity also plays a role in the inflammatory process, as fat cells produce cytokines, proteins that promote inflammation. Levels for CRP and other inflammatory markers can skyrocket off the charts in a metabolic syndrome patient, regardless of their symptoms.
In diabetes, glucose does not assimilate into the body properly. In type 2 diabetes, insulin receptor cells may become insensitive after repeated bombardment with insulin as a result of high sugar consumption. These receptors would normally open cellular pathways so glucose can enter muscle and fat cells. Unable to enter the cells, glucose stays in the bloodstream, leading to inflammation and other problems. Type 1 diabetes can result when near-constant activation of the pancreas due to sugar overconsumption causes the reduction or complete cessation of insulin production – again leading to excess blood glucose and consequent inflammation.
Whether or not a person has diabetes, excessive sugar intake – in the form of either glucose or fructose – presents as a cause of inflammation in part because it changes the pH balance of the blood. Generally, excessive sugar in the bloodstream causes the body to become overly acidic, although some people may become too alkaline. As mentioned, the body typically pulls calcium from the bones to counteract overacidity, but inflammation is still a likely result.
Chronic inflammation is the root cause of heart disease and stroke. Current research suggests that the clogged arteries that lead to these conditions are not caused simply by cholesterol sticking to blood vessel walls. Instead, excess sugar in the blood, for example, can bind to various protein molecules that damage the arterial wall. That initiates an inflammatory cascade involving various types of immune system cells as well as adhesion molecules and especially cytokines, which facilitate infiltration of the blood vessel wall, formation of plaques, and their subsequent rupture.
Obesity, another metabolic syndrome-related disease, relates to inflammation not only because fat cells release cytokines but also because obese people tend to have higher insulin, glucose, and estrogen levels – all of which lead to increased inflammation. Studies of obese adults and children suggest potentially dangerous, chronic low-grade inflammation.
Many doctors now link Alzheimer’s disease with metabolic syndrome[13,14] because they see a high number of patients with Alzheimer’s dementia who also have indicators for heart disease, hypertension, or diabetes. In fact, some doctors now refer to Alzheimer’s as type 3 diabetes. This classification makes sense because Alzheimer’s seems to function according to similar rules as clogged arteries – cytokines help make plaques, which, in this case, block neuron-receptor cells in the brain and elsewhere in the central nervous system.
Researchers have identified inflammation as a significant factor in the development of solid tumor malignances. In some types of cancer, inflammatory conditions predate malignancies, while in others, cancerous changes induce an inflammatory microenvironment that promotes tumor development. Moreover, sugar-suppressed immune systems may be hampered in their ability to combat cancerous cells.
Reducing sugar consumption
Since the inflammatory states that lead to these diseases are frequently related to or exacerbated by sugar – and since sugar is very addictive – one obvious question is: Are there any viable sugar substitutes?
Sadly, there are few, if any, good ones. Artificial sweeteners – substances such as aspartame, sucralose, and saccharin, which have been cooked up in a lab to provide a sweet flavor with few or no calories – can never be recommended. These chemicals are foreign to the body and have numerous deleterious effects.
There is one sweetener that deserves qualified support: stevia. This South American herb has no calories and, depending on the method of preparation, can be up to 300 times as sweet as table sugar. The research on stevia suggests that it has the least effect on body chemistry and inflammation of any sweetener out there. So why is my support only qualified? For some sugar addicts, the extremely sweet taste can continue to encourage the overeating of sweet foods.
Instead of looking for sugar substitutes, the best way to reduce sugar consumption is simply to eat fewer sweetened foods. As in almost any dietary change we wish to make, going slow – gradually reducing our sugar intake – usually works best. This plan is generally most effective when we obtain adequate protein and essential fats in our diet.
People often ask about fruit, which contains large amounts of fructose and glucose. Many healthy people can eat fruit in moderation without too many health risks. Robert Lustig, MD, at the University of California, San Francisco, explains that fruit contains inedible dietary fiber, which slows the absorption of the sugars, reducing their negative effects on the body. This is also a major reason that fresh fruit is healthier than fruit juices, which lack fiber.
However, unhealthy persons may find that even the sugar found in fresh fruit can exacerbate their health conditions. Moreover, in unhealthy people, excessive refined sugar consumption may upset the balance of the hormones leptin and ghrelin, which help control food intake. This imbalance may temporarily damage the satiety response, reducing their ability to push their plates away. Such people, when they attempt to develop healthier eating habits, may simply make the mistake of using fruit to replace sweetened foods at the same caloric level.
Nancy Appleton, PhD, has developed three food plans of varying strictness for people experiencing different levels of health. The food plan for the people with the most symptoms absolutely forbids fruit until the person is sufficiently healed to tolerate it. For more information about sugar, inflammation, and these food plans, see the books this author has co-written with Dr. Appleton: Stopping Inflammation, Suicide by Sugar, and Killer Colas.
About the Author
G.N. Jacobs is a general reporter, writer, and filmmaker. Among the books to his credit are several that he has co-written with Nancy Appleton, PhD. He lives in Los Angeles, where he writes several blogs and is working on a number of new books. For more information, visit www.gnjacobs.com.
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Published in the Price-Pottenger Journal of Health & Healing
Summer 2013 Volume 37 Number 2
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