While sugar in processed foods comes as sucrose, a 50:50 mix of glucose and fructose, it also comes as the ubiquitous high-fructose corn syrup, containing as much as 66 percent fructose. High-fructose corn syrup is the sweetener of choice among manufacturers, whether in low-fat salad dressing or Bloody Mary mix.
Fructose is the source of many of the problems of these sweeteners. Glucose, the same as the glucose of blood sugar, also has adverse consequences (e.g., glycation, glucose modification of proteins, an irreversible process), but fructose has greater potential to wreak havoc. This did not become clear until the processed food industry began loading up on high-fructose corn syrup, an inexpensive, cost-cutting, shelf-stable sweetener, putting fructose in virtually everything while not understanding the consequences, making you the human version of a fat lab rat. And as consumers got used to everything being sweet, it caused them to expect even greater degrees of sweetness, an appetite satisfied by increasing intake of high-fructose corn syrup—a vicious cycle, a feeding frenzy that has kids and adults alike desiring that everything be sweet and rejecting foods they should be eating.
Ironically, fructose was originally billed (and still is) as a problem-free sweetener because it did not raise blood sugar immediately following consumption. It was even thought to be the perfect sweetener for those with diabetes for that same reason. But more recent studies are clear: Fructose raises insulin and blood sugar dramatically, but the effect is delayed by several days (only prolonged monitoring uncovered the delayed effect). By an odd metabolic twist, liver processing of fructose causes an increase of triglycerides, which, in turn, triggers distortions in all other lipoproteins (fat-carrying proteins) in the bloodstream converting, for instance, large and benign LDL particles into small and heart disease–causing LDL particles. This means that fructose increases the particles in the bloodstream that lead to heart disease (despite fructose being a major ingredient in many “heart healthy” products, such as low-fat yogurt). Fructose also increases visceral fat, blood pressure, levels of uric acid (that lead to gout and heart disease), and inflammation, and it contributes to a condition called fatty liver.
So, whatever you do, don’t be tricked by claims of “low-glycemic index.” Fructose follows a different set of rules. Ingested as, say, the high-fructose corn syrup in a soft drink, ketchup or low-fat yogurt, it provokes the glycation reaction even without raising blood sugar, a stealth reaction that is difficult to detect. Even without the immediate rise in blood sugar, fructation—glycation by fructose—is eight to tenfold worse than glycation by glucose. And as with glucose-induced glycation, it is also irreversible.
In short, fructose is a lot worse than it initially appeared. Consuming it at the rate most people are consuming it—whether as sucrose, high-fructose corn syrup, other sweeteners, or even excessive quantities of fruit—is a death trap, a spinoff of the effort to reduce dietary fat that provoked a carbohydrate feeding frenzy.
Remember, any time blood sugar rises above normal, glycation occurs at an accelerated rate. What foods raise blood sugar the most, triggering the greatest degree of glycation? Grains and sugar. Fat-free and low-fat foods often contain high-fructose corn sugar. Gluten-free foods made with cornstarch, tapioca starch, potato starch, and rice flour are guilty of the same.
The Undoctored and Wheat Belly solution is to stop overstimulating the processes of glycation or fructation in the first place by eliminating, or at least managing, all the foods that are responsible for these reactions. We must aim to minimize fructose exposure to what is found naturally in fruit. Removing the appetite stimulating effects of wheat and grains via gliadin-derived opiates also will help bring the feeding frenzy of sugar in all its various forms to a halt.