By Chris Zenyuh
“Natural” is one of the most abused terms in food marketing.
Most “natural flavors,” for example, are simply chemical compounds synthesized in the same laboratories as artificial flavors using slightly different techniques and sources. Similarly, “fruit sugar” or fructose has an enticing natural sounding name, but very little of our fructose consumption actually comes from fruit. Instead, we typically accumulate fructose via table sugar — half of every teaspoon turns to fructose in our digestive system — and/or high fructose corn syrup found in almost all processed foods and beverages, even fruit juice. Though coffee and tea are, by themselves, free of fructose, the commonly consumed versions with syrups and flavoring from familiar national chains are more akin to soda, nutritionally.
When it comes to fructose, you should keep a few things in mind to keep a more healthful perspective. As a sweetener, fructose hits 170 on a scale that ranks table sugar at 100 and glucose at 70. It also tastes sweet faster, browns faster, and holds more moisture than other sugars. These characteristics have made fructose an industry favorite, especially once the chemistry behind high fructose corn syrup became cost efficient.
The only organ in your body that can process fructose is your liver. Metabolically, your body makes very little distinction between alcohol and fructose. Both are seen as poisons and both are detoxified by your liver accordingly. The primary distinction is that your brain can metabolize about 10 percent of the alcohol consumed, thus inebriation. Chronic exposure to fructose generates much of the same metabolic dysfunction as alcohol, including liver disease. Unfortunately, there is no “drinking age” for fructose, so even the youngest of children are regularly exposed to fructose.
Glucose and fructose molecules can stick to proteins in your body. This is known as glycation. The more your cells are exposed to these sugars, the more frequently this occurs. Your body does have the ability to disconnect these molecules, but too much glycation can overwhelm that system. Eventually, the attachments become permanent, known as ‘advanced glycation end-products’ or A.G.E.s (a telling acronym, for sure).
These compromised proteins cross-link with each other in a manner that disrupts their function. Collagen fibers that should slide past each other become rigid and tear under stress. Skin wrinkles, ligaments tear, and the lens of your eye can start to block light (glaucoma). Consistently high levels of exposure are recorded by your blood cells as the hemoglobin becomes glycated. Blood tests can thereby show your general glucose and fructose levels over the three months preceding the test and indicate a pre-diabetic condition.
Notably, fructose attaches to proteins seven to ten times faster than glucose, and it is harder for your body to undo these attachments. Following simple logic, that makes you age up to ten times faster, or faster than your dog.
Eating a reasonable amount of fruit is not a problem. Beware of how easy it is to consume too much dried fruit, though. And remember that the true nutritional value of fruit resides in its vitamins, antioxidants and fiber. When consumed whole, the potential negative metabolic impact of the sugars within is greatly lessened by the presence of the other nutrients, especially the fiber. Consuming ‘fruit sugar’ isolated from these beneficial components of fruit, including fruit juice, is a far more dangerous game to play with your metabolism.
Knowing how your body responds to fructose enables you to make more healthful choices regarding food and beverages. Choose well, live well.
Chris Zenyuh is a science teacher at Harborfields High School and has been teaching for