How Sugar Can Become Toxic

How Sugar Can Become Toxic

August 28, 2013 | 23,608 views

By Dr. Mercola

Mice fed a diet containing 25 percent sugar – the equivalent of three cans of soda daily – were twice as likely to die as mice fed a similar diet without sugar. 1

Such was the finding of a new 58-week University of Utah study, which once again highlights the early death sentence many Americans may receive for indulging far too often in this sweet treat.

While the mice did not display obvious signs of metabolic diseases, such as obesity, they were nonetheless significantly affected by the sugar. Male mice fed sugar were 26 percent less territorial and produced 25 percent fewer offspring, for example.

Said study author James Ruff in Time:2

“The [mice] are having fewer offspring because they are having a hard time competing, they’re less effective at foraging and raising young. That is due to lots of perturbations across their physiology.

Since most substances that are toxic in mice are also toxic in people, it’s likely that those underlying physical problems that cause those mice to have increased mortality are at play in people.”

A 19-Fold Increase in Sugar Consumption in Just Three Centuries

In Sugar Love: A Not so Sweet Story,3 author Rich Cohen chronicles the, often bloody, history of sugar and humans’ love affair with this sweet poison. One of the most noteworthy statistics is this: in 1700, the average Englishman ate four pounds of sugar a year.

This has increased steadily to reach 77 pounds of sugar annually for the average American today, which amounts to more than 22 teaspoons of added sugar daily.

And therein lies the problem. Consuming small amounts of sugar may not be a problem, but consuming sugar by the pound certainly is. As Dr. Richard Johnson, who was interviewed for the article, said:

“It seems like every time I study an illness and trace a path to the first cause, I find my way back to sugar. Why is it that one-third of adults [worldwide] have high blood pressure, when in 1900 only 5 percent had high blood pressure?

Why did 153 million people have diabetes in 1980, and now we’re up to 347 million? Why are more and more Americans obese? Sugar, we believe, is one of the culprits, if not the major culprit.”

This isn’t simply a matter of consuming ‘empty calories,’ either, as the American Heart Association would have you believe.

“It has nothing to do with its calories,” endocrinologist Robert Lustig stated. “Sugar is a poison by itself when consumed at high doses.”4

Why Calories from Sugar and Fructose May Increase Your Risk of Serious Disease

According to Dr. Lustig, fructose is "isocaloric but not isometabolic." This means you can have the same amount of calories from fructose or glucose, fructose and protein, or fructose and fat, but the metabolic effect will be entirely different despite the identical calorie count.

This is largely because different nutrients provoke different hormonal responses, and those hormonal responses determine, among other things, how much fat you accumulate.

Half of the sugar the average American consumes in a day is fructose, which is 300 percent more than the amount that will trigger biochemical havoc. And many Americans consume more than twice that amount! Thanks to the excellent work of researchers like Dr. Robert Lustig, as well as Dr. Richard Johnson, we now know that fructose:

• Is metabolized differently from glucose, with the majority being turned directly into fat.
• Tricks your body into gaining weight by fooling your metabolism, as 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 your eating more and developing insulin resistance.
• 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.
• Over time leads to insulin resistance, which is not only an underlying factor of type 2 diabetes and heart disease, but also many cancers.

This is why the general rule that you can lose weight only by counting calories simply doesn't work. After fructose, other sugars and grains are likely the most excessively consumed foods that promote weight gain and chronic disease.

This also includes food items that are typically viewed as healthy, such as fruit juice or even large amounts of high-fructose fruits. What needs to be understood is that when consumed in large amounts, these items will also adversely affect your insulin, which is a crucially potent fat regulator.

So even drinking large amounts of fruit juice on a daily basis can contribute to weight gain... In short, you do not get fat because you eat too many calories and don't exercise enough. You get fat because you eat the wrong kind of calories. As long as you keep eating fructose and grains, you're programming your body to create and store fat.

The Fat Switch: Unveiling the Five Basic Truths That Can Help You Lose Weight

Dr. Johnson discovered the method that animals use to gain fat prior to times of food scarcity, which turned out to be a powerful adaptive benefit. His research showed that fructose activates a key enzyme, fructokinase, which in turn activates another enzyme that causes cells to accumulate fat. When this enzyme is blocked, fat cannot be stored in the cell.

Interestingly, this is the exact same "switch" animals use to fatten up in the fall and to burn fat during the winter. Fructose is the dietary ingredient that turns on this "switch," causing cells to accumulate fat, both in animals and in humans. His latest book, The Fat Switch, dispels many of the most pervasive myths relating to diet and obesity. There are five basic truths that Dr. Johnson explains in detail in the book that overturn current concepts:

1. Large portions of food and too little exercise are NOT solely responsible for why you are gaining weight
2. Metabolic Syndrome is actually a healthy adaptive condition that animals undergo to store fat to help them survive periods of famine. The problem is most all of us are always feasting and never undergo fasting. Our bodies have not adapted to this yet and as a result, this beneficial switch actually causes damage to contemporary man
3. Uric acid is increased by specific foods and causally contributes to obesity and insulin resistance
4. Fructose-containing sugars cause obesity not by calories but by turning on the ‘fat switch’
5. Effective treatment of obesity requires turning off your fat switch and improving the function of your cells' mitochondria

I highly recommend picking up a copy of this book, which is a useful tool for those struggling with their weight. Dietary sugar, and fructose in particular, is a significant "tripper of your fat switch," so understanding how sugars of all kinds affect your weight and health is imperative.

Is Any Amount of Sugar Safe?

Excess sugar consumption has been clearly linked to health problems like diabetes,5 heart attack6 and much more, so it’s likely that the less sugar you eat, the better, and this is particularly true when it comes to fructose. As a standard recommendation, I advise keeping your TOTAL fructose consumption below 25 grams per day. For most people, it would also be wise to limit your fructose from fruit to 15 grams or less, as you're virtually guaranteed to consume "hidden" sources of fructose if you drink beverages other than water and eat processed food.

Fifteen grams of fructose is not much -- it represents two bananas, one-third cup of raisins, or two Medjool dates. Remember, the average 12-ounce can of soda contains 40 grams of sugar, at least half of which is fructose, so one can of soda alone would exceed your daily allotment.  

I realize that there is a controversy over fructose from fruits. I believe that the average American will benefit from following these fructose restrictions, as many are seriously overweight. But for those who are fit and normal body weight, I suspect you could increase those levels significantly if the fructose is from WHOLE fruit, not juice, and not suffer any complications. More than likely you would receive health benefits from the phytonutrients in the fruit as long as you were fit and not overweight.

In his book, The Sugar Fix, Dr. Johnson includes detailed tables showing the content of fructose in different foods -- an information base that isn't readily available when you're trying to find out exactly how much fructose is in various foods. I encourage you to pick up a copy of this excellent resource. You can find an abbreviated listing of the fructose content of