Consuming high-fructose corn syrup is the fastest way to trash your health. It is now known without a doubt that sugar in your food, in all its myriad of forms, is taking a devastating toll.
And fructose in any form — including high-fructose corn syrup (HFCS) and crystalline fructose — is the worst of the worst! Fructose, a cheap sweetener usually derived from corn, is used in thousands of food products and soft drinks. Excessive fructose consumption can cause metabolic damage and triggers the early stages of diabetes and heart disease, which is what the Davis study showed.
A Calorie Is Not a Calorie
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 Earth — uses glucose for energy.
If you received your fructose only from vegetables and fruits (where it originates) as most people did a century ago, you’d consume about 15 grams per day — a far cry from the 73 grams per day the typical adolescent gets from sweetened drinks. In vegetables and fruits, it’s mixed in with fiber, vitamins, minerals, enzymes, and beneficial phytonutrients, all which moderate any negative metabolic effects.
It isn’t that fructose itself is bad — it is the MASSIVE DOSES you’re exposed to that make it dangerous. There are two reasons fructose is so damaging:
Your body metabolizes fructose in a much different way from glucose. The entire burden of metabolizing fructose falls on your liver.
People are consuming fructose in enormous quantities, which has made the negative effects much more profound.
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 HFCS.
Food and beverage manufacturers began switching their sweeteners from sucrose (table sugar) to corn syrup in the 1970s when they discovered that HFCS was not only far cheaper to make, but is also about 20% sweeter than table sugar. HFCS is either 42% or 55% fructose, and sucrose is 50% fructose, so it’s really a wash in terms of sweetness.
Still, this switch drastically altered the average American diet.
By USDA estimates, about one-quarter of the calories consumed by the average American is in the form of added sugars, and most of that is HFCS. The average Westerner consumes a staggering 142 pounds a year1 of sugar! And the very products most people rely on to lose weight — the low-fat diet foods — are often the ones highest in fructose. Making matters worse, all of the fiber has been removed from these processed foods, so there is essentially no nutritive value at all.
Fructose Metabolism Basics
Without getting into the very complex biochemistry of carbohydrate metabolism, it is important to understand some differences about how your body handles glucose versus fructose. I will be publishing a major article about this in the next couple of months, which will get much more into the details. But for our purpose here, I will just summarize the main points.
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:
After eating fructose, 100 percent of the metabolic burden rests on your liver. But with glucose, your liver has to break down only 20 percent.
Every cell in your body, including your brain, utilizes glucose. Therefore, much of it is “burned up” immediately after you consume it. By contrast, fructose is turned into free fatty acids (FFAs), VLDL (the damaging form of cholesterol), and triglycerides, which get stored as fat.
The fatty acids created during fructose metabolism accumulate as fat droplets in your liver and skeletal muscle tissues, causing insulin resistance and non-alcoholic fatty liver disease (NAFLD). Insulin resistance progresses to metabolic syndrome and type II diabetes.
Fructose is the most lipophilic carbohydrate. In other words, fructose converts to activated glycerol (g-3-p), which is directly used to turn FFAs into triglycerides. The more g-3-p you have, the more fat you store. Glucose does not do this.
When you eat 120 calories of glucose, less than one calorie is stored as fat. 120 calories of fructose results in 40 calories being stored as fat. Consuming fructose is essentially consuming fat!
The metabolism of fructose by your liver creates a long list of waste products and toxins, including a large amount of uric acid, which drives up blood pressure and causes gout.
Glucose suppresses the hunger hormone ghrelin and stimulates leptin, which suppresses your appetite. Fructose has no effect on ghrelin and interferes with your brain’s communication with leptin, resulting in overeating.
If anyone tries to tell you “sugar is sugar,” they are way behind the times. As you can see, there are major differences in how your body processes fructose and glucose. The bottom line is: fructose leads to increased belly fat, insulin resistance, and metabolic syndrome — not to mention the long list of chronic diseases that directly result. And eating sugar may accelerate the aging process itself.