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Fructose... the deadly sweet
Article written by Kaye Sehm, posted
We all need to be educated regarding to the food we put in our bodies. Many are unaware that many of the foods we buy have the potential to cause us serious health problems and can even lead to our death. This article considers the additive used to sweeten food which is called either fructose or corn fructose. Is this simply another sweetener that only adds to the taste of foods, or is it dangerous to our health?
What is fructose?
Fructose is a simple sugar (monosaccharide), which the body can use for energy. It is found in fruits and many foods. These foods, when eaten as a whole food have no problem. The nutrients, antioxidants, fibre and other synergistic compounds counter any detrimental effect as the fructose is absorbed slowly into our bodies. But when taken into the body as pure refined fructose that has been added to sweeten foods, and 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, nutritional experts have changed their minds about this.
So 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 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 directed to high fructose corn syrup (HFCS), which is made up of 55% fructose and 45% glucose. However, sucrose is half fructose and half glucose. So, HFCS actually doesn't have a whole lot more fructose than "regular" sugar, gram for gram.
High fructose corn syrup has become incredibly inexpensive and abundant, partially due to corn subsidies in the United States. So, really, the problem is more that it has become so cheap that it has crept its way into a great number of the foods we eat every day.
Corn syrup fructose is no different than fructose found in other foods. All fructose works the same in the body, whether it comes from corn syrup, cane sugar, beet sugar, strawberries, onions, or tomatoes. Only the amounts are different. For example, a cup of chopped tomatoes has 2.5 grams of fructose, a can of regular (non-diet) soda supplies 23 grams, and a super-size soft drink has about 62 grams.
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). Look at the ingredients on packaged food labels and you will probably see sources of fructose.
In order to appreciate just how damaging fructose is to your body, it is crucial to have a basic understanding of how different types of carbohydrates are metabolized. Glucose is the basic fuel for living organisms, and is the primary energy source for your brain. It is a product of photosynthesis and is found in rice, corn and other grains, and bread and pasta. Once you take in glucose from a meal, 80 percent of it is used by all of the organs of your body - every single cell. The remaining 20 percent goes to your liver to be metabolized and stored.
The 20 percent that reaches the liver is converted into glycogen to be stored in the liver. Glycogen is your body's nontoxic short-term energy storage package, where it can be easily converted to energy when you need it. Your liver has no limit to how much glycogen it can store without detrimental effects. (That is what athletes take advantage of when they "carboload.") A small amount of pyruvate (for energy) and citrate (as VLDL) is produced. Insulin is produced to process the glucose from the blood stream into the cells. When you consume 120 calories of glucose, less than one calorie contributes to adverse metabolic outcomes.
Ethanol, or ethyl alcohol, (caused when sugar ferments) is the favourite carbohydrate of many. But it is also a carbohydrate that undergoes a very different metabolic process, leaving in its wake a trail of toxins a mile long. Ethanol is an acute central nervous system toxin and must be metabolized almost completely in the liver. But the metabolic process in the liver is quite different from that of glucose. It produces free radicals that damage proteins of the liver, converts to bad cholesterol VLDL, liver inflammation, cirrhosis, fatty liver disease, insulin resistance (which leads to Type 2 diabetes). After a 120-calorie intake of ethanol, a large fraction (about 40 calories) can contribute to disease.
In nearly every way, fructose is metabolized the same way as ethanol, creating the same toxins in your body. When you consume fructose, one hundred percent of it goes directly to your liver to be metabolized. It overloads the liver. It depletes your liver cells of phosphates, produces uric acid which in turn raises blood pressure, produces high cholesterol (bad type), converts into fat cells (belly fat), causes insulin resistance (which leads to Type 2 diabetes) and fatty liver disease, Fructose metabolism is similar to a dose of ethanol (alcohol), a 120-calorie intake of fructose results in a large fraction (again, about 40 calories) that directly contributes to disease.
The point to take away is: consuming fructose is consuming fat. Fructose is not really a carbohydrate - a high fructose diet is a HIGH FAT diet. A high fat diet that creates a vicious cycle of consumption that won't turn itself off.
You can see by comparing the metabolism of fructose with the metabolism of ethanol that they are very similar. In fact, when you compare the metabolism of 150 calories of soda with 150 calories of beer (a 500ml can of each), about 90 calories reach the liver in either case. Fructose causes most of the same toxic effects as ethanol because both come from sugar fermentation.
Two other studies were done using medical students, both looking at biological responses to fructose loading. In the first, the students were given either a large glucose load or a large fructose load. In the students given fructose, almost 30 percent of the calories ended up as fat. In the students given glucose, almost none ended up as fat. In the second study, medical students were given a high fructose diet for 6 days. In just that short time, their insulin resistance and triglycerides doubled!
We normally have pathways in our brains that regulate when we stop eating. Fructose undermines these normal satiety signals, increasing caloric consumption both directly and indirectly. Fructose does not stimulate a leptin rise, so your satiety signals are diminished. Glucose suppresses the hunger hormone- it makes you want more food, but fructose does not.
Dr. Richard Johnson, is a professor of medicine at the University of Colorado where he runs the kidney other healthrelated problems has proven how uric acid in your blood can wreak havoc on your blood pressure, insulin production and even kidney function. He didn't start by looking at fructose however. It began when he realized that uric acid is a major component of obesity, high blood pressure and kidney disease.
In fact, he discovered that newly diagnosed adolescents with high blood pressure had elevated uric acid levels 90 percent of the time. And by lowering uric acid in these obese, hypertensive adolescents, he was able to normalize blood pressure in 87 percent of all cases. It's been known that meats and purine rich foods can raise uric acid, but it turns out that one of the most potent ways to raise uric acid is via fructose!
You probably already know that fructose is a sugar, but remember that it's distinctly different from other sugars as it's metabolized through very specific pathways that differ from those of glucose, which generates uric acid. In fact, fructose typically generates uric acid within minutes of ingestion.
But let's take a step back and look at what uric acid is, and how it's linked to fructose consumption.
What is Uric Acid and How
Much is Too Much? Uric acid is a normal waste product found in your blood. High levels of uric acid are normally associated with gout, but it has been known for a long time that people with high blood pressure, overweight, and people with kidney disease, often have high uric acid levels as well.
Dr. Johnson believes the ideal range for uric acid lies between 3 to 5.5 mg per dl. In the following statement, Dr. Johnson explains just how closely tied uric acid levels are to fructose consumption:
"If you give animals fructose, they develop diabetes, hypertension, obesity, and fatty liver. And in most of these conditions, if we lower uric acid, we can prevent many of these conditions, [although] not completely. So lowering uric acid seems to benefit some of the mechanisms by which fructose causes disease. So a very important point is that if you take two animals and you feed one fructose and feed the other one the exact same number of calories but give it as dextrose or glucose, its only the fructose-fed animal that will develop obesity, insulin resistance, fatty liver, and high triglycerides, signs of inflammation, vascular disease, and high blood pressure."
This bears out in humans as well. Over the last 20 years, we've seen a dramatic increase in fatty liver disease throughout the world, and studies done by Dr. Johnson and a group of researchers at Duke University showed that people who develop fatty liver drink a lot more soft drinks, and ingest far more fructose than the average person in the community.
For an informed lecture on this on the web, watch Sugar: The Bitter Truth by Robert H Lustig MD., Professor of Pediatrics in the Division of Endocrinology at University of California in San Francisco.
How Much Fructose are You Consuming?
It's no secret that we are eating more sugar than at any other time in history. In 1700, the average person ate 2kg of sugar a year. By 1800, it was 9kg. By 1900 it was about 45kg. Today, about 25 percent of all people on the Western diet consume over 95 kg of sugar per year! And it just so happens this statistic corresponds nicely with the statistics showing that one in four Westerners is either prediabetic or has type 2 diabetes.
The two main sources of that sugar are high fructose corn syrup (HFCS) and table sugar. As a standard recommendation, it is strongly recommended keeping your total fructose consumption below 25 grams per day.
However, for most people it would actually be wise to limit your fruit fructose to 15 grams or less, as it is virtually guaranteed that you will consume "hidden" sources of fructose from most beverages and just about any processed food you might eat.
Since 55 percent of HFCS is fructose, one can of soft drink alone would nearly exceed your daily allotment. It is easy to see that anyone who is drinking three, and certainly four will easily exceed 100 grams of fructose per day.
Fructose consumption clearly causes insulin resistance, whereas straight glucose does not. Insulin resistance can eventually lead to full blown diabetes. Interestingly, glucose actually accelerates fructose absorption. So when you mix glucose and fructose together, you absorb more fructose than if you consumed fructose alone.
This is an important piece of information for people who want to make a better effort at controlling their weight. With an epidemic of obesity going on in this country - two out of three people are overweight, and one out of three is obese - it has become clear that fructose is the single most important factor in this epidemic.
A Second Uric Acid Trigger
In his studies, Dr. Johnson found one more common substance that also elevates uric acid levels, namely beer! It turns out that the yeast and all that's used to make beer work together to make beer another powerful uric acid trigger.
The classic "beer belly syndrome," is also quite similar to metabolic syndrome, and includes abdominal obesity, high triglycerides, high blood pressure, and even insulin resistance.
While this concept is still new, pilot studies support Dr. Johnson's findings, so beer consumption is also something to definitely consider when you're watching your weight and trying to improve your health.
The food and beverage industry doesn't want you to realize how truly pervasive HFCS is in your diet - not just from soft drinks and juices, but also in salad dressings and condiments and virtually every processed food. The introduction of HFCS into the Western diet in 1975 has been a multi-billion dollar boon for the corn industry. An remember that HFCS is made with genetically modified corn which comes with another new set of risks.
Now the corn industry has come up with another product it's using in beverages called "crystalline fructose." This is produced by allowing the fructose to crystallize from a fructose-enriched corn syrup, resulting in a product that is 99.5 percent pure fructose - a fructose level twice as high as regular HFCS! Clearly, all the health problems associated with HFCS could become even more pronounced with this product.
Making matters worse, crystalline fructose may also contain arsenic, lead, chloride and heavy metals - a list of toxic agents you should clearly avoid. In fact, more than one study has detected unsafe mercury levels in HFCS. If you have children, all of these contaminants can impact your child's development and long-term health.
Ideally, I recommend that you avoid as much sugar as possible. This is especially important if you are overweight or have diabetes, high cholesterol, or high blood pressure. Yes it takes time to break a sugar addiction, but it can be done. Use raw honey in moderation or you may use the herb Stevia. Avoid ALL artificial sweeteners, which can damage your health even more quickly than HFCS. Avoid agave syrup since it is a highly processed sap that is almost all fructose. Your blood sugar will spike just as it would if you were consuming regular sugar or HFCS. Agave has gained meteoric popularity due to a great marketing campaign, but any health benefits present in the original agave plant are processed away. Be sure to eat your sugar with fiber ... as in a piece of fruit.
Wait 20 minutes before second portions at meals, giving your brain a chance to receive satiety signals. And exercise regularly. Exercise is important for many reasons. Avoid so-called energy drinks and sports drinks because they are loaded with sugar, sodium and chemical additives. Rehydrating with pure, fresh water is a better choice.
Reducing sugar in your diet can be tough for some people. After all, sugar is just as addictive as cocaine! Try following a very low fructose diet for two weeks, which has the effect of "rebooting" your system. Sugar activates its own pathways, and the more sugar you eat, the more sensitive you become to it, and the more your body starts absorbing. By cutting out sugar for a period of time, you can reduce the hyperactive metabolic system that has developed, and start over. You will develop a taste that does not crave for sweets.
A Word of Warning About Infant Formula
And finally, be extremely careful about the infant formula you are feeding your baby. Nearly all infant formulas have as much or more high fructose corn syrup than a can of soft drink - in addition to many other things that are extremely detrimental to your baby's health and development. You have learned that, metabolically, there is very little difference between ethanol and sugar so by giving your infant formula, you might as well be giving him a bottle of beer or soda! And studies have shown that the earlier you expose kids to sweets, the more they crave them later.
It is important for pregnant women to keep their blood sugars well managed not only for their own health, but also for the long-term health of their children. Researchers have found that children born to mothers with gestational diabetes (high blood sugar during pregnancy) had an 82 percent chance of becoming obese between the ages of 5 and 7 through a phenomenon called "metabolic imprinting." Even mothers with elevated blood sugar, short of gestational diabetes, had children with a significantly increased risk for obesity.
It should be very clear how careful we need to be when preparing food for our tables. Fructose as well a refined table sugar will cause may health problems.
Fortunately, your body has an amazing ability to heal itself when given the basic nutrition it needs, and your liver has an incredible ability to regenerate. If you start making changes today, your health will begin to improve, returning you to the state of vitality that nature intended.
www.Mercola March 13,2010
www.mercola Jan 20,2010
Article written by Kaye Sehm, posted with permission.