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  • One of the primary sources of calories for Americans is sugar—specifically high fructose corn syrup in soda and processed foods. Because of advances in food processing technology in the 1970s, fructose derived from corn has become very cheap and is widely used in the majority of processed foods for increased sales.
  • Sugar takes a devastating toll on your health. In fact, excessive sugar consumption may be the largest factor underlying obesity and chronic disease in America
  • Your body metabolizes fructose much differently from glucose; the entire burden of metabolizing fructose falls on your liver, where excess fructose is quickly converted into fat, which explains the weight gain and abdominal obesity experienced by so many Westerners
  • Fructose is the primary cause of non-alcoholic fatty liver and elevates uric acid, which raises your blood pressure, stresses your kidneys, and leads to the chronic, low-level inflammation that is at the core of most chronic diseases; metabolically speaking, fructose is alcohol “without the buzz”
  • It would be wise for most people to limit their daily fructose consumption to less than 25 grams per day; a table showing the fructose content of many foods is provided, especially if you show signs of insulin resistance such as being overweight, have high blood pressure, high cholesterol, or diabetes
 

Fructose: This Addictive Commonly Used Food Feeds Cancer Cells, Triggers Weight Gain, and Promotes Premature Aging

April 20, 2010 | 1,260,211 views
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Death by sugar may not be an overstatement—evidence is mounting that sugar is THE MAJOR FACTOR causing obesity and chronic disease.
 

Dr. Mercola's Comments:

Is sugar a sweet old friend that is secretly plotting your demise?

There is a vast sea of research suggesting that it is. Science has now shown us, beyond any shadow of a doubt, that sugar in your food, in all its myriad of forms, is taking a devastating toll on your health.

The single largest source of calories for Americans comes from sugar—specifically high fructose corn syrup. Just take a look at the sugar consumption trends of the past 300 years:1

  • In 1700, the average person consumed about 4 pounds of sugar per year.
  • In 1800, the average person consumed about 18 pounds of sugar per year.
  • In 1900, individual consumption had risen to 90 pounds of sugar per year.
  • In 2009, more than 50 percent of all Americans consume one-half pound of sugar PER DAY—translating to a whopping 180 pounds of sugar per year!

Sugar is loaded into your soft drinks, fruit juices, sports drinks, and hidden in almost all processed foods—from bologna to pretzels to Worcestershire sauce to cheese spread. And now most infant formula has the sugar equivalent of one can of Coca-Cola, so babies are being metabolically poisoned from day one of taking formula.

No wonder there is an obesity epidemic in this country.

Today, 32 percent of Americans are obese and an additional one-third is overweight. Compare that to 1890, when a survey of white males in their fifties revealed an obesity rate of just 3.4 percent. In 1975, the obesity rate in America had reached 15 percent, and since then it has doubled.

Carrying excess weight increases your risk for deadly conditions such as heart disease, kidney disease, and diabetes.

In 1893, there were fewer than three cases of diabetes per 100,000 people in the United States. Today, diabetes strikes almost 8,000 out of every 100,000 people.1

You don't have to be a physician or a scientist to notice America's expanding waistline. All you have to do is stroll through a shopping mall or a schoolyard, or perhaps glance in the mirror.

Sugars 101 -- Basics of How to Avoid Confusion on This Important Topic

It is easy to become confused by the various sugars and sweeteners. So here is a basic overview:

  • Dextrose, fructose, and glucose are all monosaccharides, known as simple sugars. The primary difference between them is how your body metabolizes them. Glucose and dextrose are essentially the same sugar. However, food manufacturers usually use the term "dextrose" in their ingredient list.
  • The simple sugars can combine to form more complex sugars, like the disaccharide sucrose (table sugar), which is half glucose and half fructose.
  • High fructose corn syrup (HFCS) is 55 percent fructose and 45 percent glucose.
  • Ethanol (drinking alcohol) is not a sugar, although beer and wine contain residual sugars and starches, in addition to alcohol.
  • Sugar alcohols like xylitol, glycerol, sorbitol, maltitol, mannitol, and erythritol are neither sugars nor alcohols but are becoming increasingly popular as sweeteners. They are incompletely absorbed from your small intestine, for the most part, so they provide fewer calories than sugar but often cause problems with bloating, diarrhea, and flatulence.
  • Sucralose (Splenda) is NOT a sugar, despite its sugar-like name and deceptive marketing slogan, "made from sugar." It's a chlorinated artificial sweetener in line with aspartame and saccharin, with detrimental health effects to match.
  • Agave syrup, falsely advertised as "natural," is typically HIGHLY processed and is usually 80 percent fructose. The end product does not even remotely resemble the original agave plant.
  • Honey is about 53 percent fructose2, but is completely natural in its raw form and has many health benefits when used in moderation, including as many antioxidants as spinach.
  • Stevia is a highly sweet herb derived from the leaf of the South American stevia plant, which is completely safe (in its natural form). Lo han (or luohanguo) is another natural sweetener, but derived from a fruit.

All Sugars Are Not Equal

Glucose is the form of energy you were designed to run on. Every cell in your body, every bacterium—and in fact, every living thing on the Earth—uses glucose for energy.

But in this country, sucrose is no longer the sugar of choice. It's now fructose.

If your diet was like that of people a century ago, you'd consume about 15 grams per day—a far cry from the 73 grams per day the typical person gets from sweetened drinks. In vegetables and fruits, it's mixed in with vitamins, minerals, enzymes, and beneficial phytonutrients, all which moderate the negative metabolic effects. Amazingly, 25 percent of people actually consume more than 130 grams of fructose per day.

Making matters worse, all of the fiber has been removed from processed foods, so there is essentially no nutritive value at all. And the very products most people rely on to lose weight—the low-fat diet foods—are often the ones highest in fructose.

It isn't that fructose itself is bad—it is the MASSIVE DOSES you're exposed to that make it dangerous.

There are two overall reasons fructose is so damaging:

  1. Your body metabolizes fructose in a much different way from glucose. The entire burden of metabolizing fructose falls on your liver.
  2. People are consuming fructose in enormous quantities, which has made the negative effects much more profound.

The explosion of soda consumption is the major cause of this.

Today, 55 percent of sweeteners used in food and beverage manufacturing are made from corn, and the number one source of calories in America is soda, in the form of high fructose corn syrup.

Food and beverage manufacturers began switching their sweeteners from sucrose to corn syrup in the 1970s when they discovered that HFCS was not only far cheaper to make, but is also about 20 percent sweeter than conventional table sugar that has sucrose.

HFCS contains the same two sugars as sucrose but is more metabolically risky to you, due to its chemical form.

The fructose and the glucose are not bound together in HFCS, as they are in table sugar, so your body doesn't have to break it down. Therefore, the fructose is absorbed immediately, going straight to your liver.

Too Much Fructose Creates a Metabolic Disaster in Your Body

Dr. Robert Lustig, Professor of Pediatrics in the Division of Endocrinology at the University of California, San Francisco, has been a pioneer in decoding sugar metabolism. His work has highlighted some major differences in how different sugars are broken down and used by the human body.

I highly recommend watching Lustig's lecture in its entirety if you want to learn how fructose is ruining your health biochemically.

As I mentioned earlier, after eating fructose, most of the metabolic burden rests on your liver. This is NOT the case with glucose, of which your liver breaks down only 20 percent. Nearly every cell in your body utilizes glucose, so it's normally "burned up" immediately after consumption.

So where does all of this fructose go, once you consume it?

Onto your thighs. It is turned into FAT (VLDL and triglycerides), which means more fat deposits throughout your body.

Eating Fructose Is Far Worse Than Eating Fat

However, the physiological problems of fructose metabolism extend well beyond a couple of pant sizes:

  • Fructose elevates uric acid, which decreases nitric oxide, raises angiotensin, and causes your smooth muscle cells to contract, thereby raising your blood pressure and potentially damaging your kidneys.1

    Increased uric acid also leads to chronic, low-level inflammation, which has far-reaching consequences for your health. For example, chronically inflamed blood vessels lead to heart attacks and strokes; also, a good deal of evidence exists that some cancers are caused by chronic inflammation. (See the next section for more about uric acid.)
  • Fructose tricks your body into gaining weight by fooling your metabolism—it turns off your body's appetite-control system. Fructose does not appropriately stimulate insulin, which in turn does not suppress ghrelin (the "hunger hormone") and doesn't stimulate leptin (the "satiety hormone"), which together result in you eating more and developing insulin resistance.2
  • Fructose rapidly leads to weight gain and abdominal obesity ("beer belly"), decreased HDL, increased LDL, elevated triglycerides, elevated blood sugar, and high blood pressure—i.e., classic metabolic syndrome.
  • Fructose metabolism is very similar to ethanol metabolism, which has a multitude of toxic effects, including NAFLD (non-alcoholic fatty liver disease). It's alcohol without the buzz.

These changes are not seen when humans or animals eat starch (or glucose), suggesting that fructose is a "bad carbohydrate" when consumed in excess of 25 grams per day. It is probably the one factor responsible for the partial success of many "low-carb" diets.

One of the more recent findings that surprised researchers is that glucose actually accelerates fructose absorption, making the potential health risks from HFCS even more profound.1

You can now see why fructose is the number one contributing factor to the current obesity epidemic.

Is Uric Acid the New Cholesterol?

By now you are probably aware of the childhood obesity epidemic in America—but did you know about childhood hypertension?

Until recently, children were rarely diagnosed with high blood pressure, and when they were, it was usually due to a tumor or a vascular kidney disease.

In 2004, a study showed hypertension among children is four times higher than predicted: 4.5 percent of American children have high blood pressure. Among overweight children, the rate is 10 percent. It is thought that obesity is to blame for about 50 percent of hypertension cases in adolescents today.

Even more startling is that 90 percent of adolescents who have high blood pressure have elevated uric acid levels.

This has led researchers to ask: what does uric acid have to do with obesity and high blood pressure?

In his book, The Sugar Fix: The High-Fructose Fallout That is Making You Fat and Sick, Dr. Robert J. Johnson makes a compelling argument for a previously unrecognized connection between excess sugar consumption and high uric acid levels. However, he promotes artificial sweeteners as an alternative to sugar and makes other recommendations that I don't agree with.

Dr. Johnson is a conventional physician who has not accepted large parts of natural medicine. However, he is one of the leading researchers defining the extent of fructose toxicity. He has spent many years of his life dedicating himself to uncover this mystery.

There are more than 3,500 articles to date showing a strong relationship between uric acid and obesity, heart disease, hypertension, stroke, kidney disease, and other conditions. In fact, a number of studies have confirmed that people with elevated serum uric acid are at risk for high blood pressure, even if they otherwise appear to be perfectly healthy.

Uric acid levels among Americans have risen significantly since the early half of the 20th century. In the 1920s, average uric acid levels were about 3.5 ml/dl. By 1980, average uric acid levels had climbed into the range of 6.0 to 6.5 ml/dl and are probably much higher now.

How Does Your Body Produce Uric Acid?

It's a byproduct of cellular breakdown. As cells die off, DNA and RNA degrade into chemicals called purines. Purines are further broken down into uric acid.

Fructose increases uric acid through a complex process that causes cells to burn up their ATP rapidly, leading to "cell shock" and increased cell death. After eating excessive amounts of fructose, cells become starved of energy and enter a state of shock, just as if they have lost their blood supply. Massive cellular die-off leads to increased uric acid levels.

And cells that are depleted of energy become inflamed and more susceptible to damage from oxidative stress. Fat cells actually become "sickly," bloating up with excessive amounts of fat.

There is a simple, inexpensive blood test for determining your uric acid level, which I recommend you have done as part of your routine health checkups. Your level should be between 3.0 and 5.5 mg/dl, optimally.

There is little doubt in my mind that your uric acid level is a more potent predictor of cardiovascular and overall health than your total cholesterol level is. Yet virtually no one is screening for this.

Now that you know the truth, you don't have to be left out in the cold, as this is a simple and relatively inexpensive test that you can get at any doctor's office. Odds are very good your doctor is clueless about the significance of elevated uric acid levels, so it will not likely be productive to engage in a discussion with him unless he is truly an open-minded truth seeker.

Merely get your uric acid level, and if it is over 5 then eliminate as much fructose as you can (also eliminate all beer), and retest your level in a few weeks.

Sugar Sensitization Makes the Problem Even WORSE!

There is yet another problem with sugar—a self-perpetuating one.

According to Dr. Johnson, sugar activates its own pathways in your body—those metabolic pathways become "upregulated." In other words, the more sugar you eat, the more effective your body is in absorbing it; and the more you absorb, the more damage you'll do.

You become "sensitized" to sugar as time goes by, and more sensitive to its toxic effects as well.

The flip side is, when people are given even a brief sugar holiday, sugar sensitization rapidly decreases and those metabolic pathways become "downregulated." Research tells us that even two weeks without consuming sugar will cause your body to be less reactive to it.

Try it for yourself! Take a two-week sugar sabbatical and see how different you feel.

Are Fruits Good or Bad for You?

Keep in mind that fruits also contain fructose, although an ameliorating factor is that whole fruits also contain vitamins and other antioxidants that reduce the hazardous effects of fructose.

Juices, on the other hand, are nearly as detrimental as soda, because a glass of juice is loaded with fructose, and a lot of the antioxidants are lost.

It is important to remember that fructose alone isn't evil, as fruits are certainly beneficial. But when you consume high levels of fructose, it will absolutely devastate your biochemistry and physiology. Remember the AVERAGE fructose dose is 70 grams per day, exceeding the recommend limit by 300 percent.

So please BE CAREFUL with your fruit consumption. You simply MUST understand that because HFCS is so darn cheap, it is added to virtually every processed food. Even if you consumed no soda or fruit, it is very easy to exceed 25 grams of hidden fructose in your diet.

If you are a raw food advocate, have a pristine diet, and exercise very well, then you could be the exception that could exceed this limit and stay healthy.

Dr. Johnson has a handy chart shown below, which you can use to estimate how much fructose you're getting in your diet. Remember, you are also likely getting additional fructose if you consume any packaged foods at all, since it is hidden in nearly all of them.

Fruit Serving Size Grams of Fructose
Limes 1 medium 0
Lemons 1 medium 0.6
Cranberries 1 cup 0.7
Passion fruit 1 medium 0.9
Prune 1 medium 1.2
Apricot 1 medium 1.3
Guava 2 medium 2.2
Date (Deglet Noor style) 1 medium 2.6
Cantaloupe 1/8 of med. melon 2.8
Raspberries 1 cup 3.0
Clementine 1 medium 3.4
Kiwifruit 1 medium 3.4
Blackberries 1 cup 3.5
Star fruit 1 medium 3.6
Cherries, sweet 10 3.8
Strawberries 1 cup 3.8
Cherries, sour 1 cup 4.0
Pineapple 1 slice
(3.5" x .75")
4.0
Grapefruit, pink or red 1/2 medium 4.3
Fruit Serving Size Grams of Fructose
Boysenberries 1 cup 4.6
Tangerine/mandarin orange 1 medium 4.8
Nectarine 1 medium 5.4
Peach 1 medium 5.9
Orange (navel) 1 medium 6.1
Papaya 1/2 medium 6.3
Honeydew 1/8 of med. melon 6.7
Banana 1 medium 7.1
Blueberries 1 cup 7.4
Date (Medjool) 1 medium 7.7
Apple (composite) 1 medium 9.5
Persimmon 1 medium 10.6
Watermelon 1/16 med. melon 11.3
Pear 1 medium 11.8
Raisins 1/4 cup 12.3

 


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