Health and wellness are apparently illusive characteristics of the human condition today. I submit this month another look at our food supply with the hope of shedding some light on what we consume and the volume in which we consume it.
Is fructose (corn syrup) just alcohol without the buzz??
I would like to focus the spotlight on high fructose corn syrup (HFCS). HFCS is a “natural” sweetener which and the primary ingredient of any sweetened processed food available today. It has become the darling of the processed food industry for its intensity of sweetness, behavior in solution and the beautiful effect it has on baked goods. It is the refined by product of the processing of corn. A process where the light sweetened kiss of the natural sugar of corn is processed into a super concentrated sweetener. Fructose is a naturally occurring sugar and is the primary sugar in fruit. Fructose, however, is different from table sugar. Table sugar is scientifically referred to as sucrose, a DI-saccharide. This means it is a complex sugar composed of two simple sugars: glucose and fructose. Remember this…we’ll get back to it.
The only fuel the human body can burn is glucose. All the fuels we consume throughout the day like carbohydrates, protein and fat must be converted into glucose in order to be used as fuel by the body. Insulin is required by all of your body tissues in order utilize glucose for fuel. This is the body’s check and balance system for resource management. Your brain is the only organ in your body that does NOT require insulin to utilize glucose. This ensures that no matter what your brain can maintain consciousness throughout the day. In times of starvation insulin levels stay low and the small amount of glucose available will be committed to basic bodily functions and the brain will maintain consciousness. Overall, simple and genius design.
It is claimed by the corn industry that corn sugar, high fructose corn syrup, is just sugar and therefore not bad for you. I submit today that high fructose corn syrup is NOT just like table sugar and I will show you why.
Table sugar, upon consumption, is cleaved by enzymes in the GI tract into the parent molecules, the monosaccharaides, glucose and fructose. The glucose is absorbed at the surface of the intestinal cell without the addition of energy. It in essence is passively absorbed. It ascends via the blood stream to your body organs for immediate use. Glucose initiates an insulin response and utilization is distributed across body tissues in a consistent manner. So simple…the fuel we are meant to have, absorbed so easily. Fructose, however, takes a much more twisted path.
Absorption of fructose requires an active transport mechanism. This means energy must be spent in order to take up fructose. This is because fructose is not a primary fuel of the human body. It has a tendency to remain in your GI tract and NOT be absorbed. This is why fruit juice in children can cause diarrhea. Fructose is primary fuel for the liver. Fructose does create an insulin response like its cousin glucose. Fructose is NOT readily converted into glucose for use. Remember circulating insulin levels are only low when we are fasting or hungry, rarely the situation when consuming sources of HFCS. In the fasting state, dietary fructose will be converted into glycogen. Glycogen is a storage molecule made by the liver to supply the body with glucose when we are fasting. When we are in a state of calorie excess no glycogen production is needed and fructose metabolism is shunted to the production of blood fat. Upon the production of blood fat, the fat is transported to body tissues for storage. As it turns out the fructose consumed is rarely available to be used as fuel and goes immediately to the production of fat. A by-product of fat production is free radicals. In small amounts, like found naturally in fruit, anti-inflammatory molecules found in the liver consume the free radicals. In large amounts, like encountered when drinking a soda, these free radicals lead to liver inflammation and liver damage. The chronic inflammation associated with liver fat metabolism ultimately leads to liver dysfunction and liver failure or cirrhosis.
Alcohol when absorbed by the GI tract enters the same metabolic pathway as fructose with one exception. Alcohol immediately enters the blood fat pathway in the liver and results in the exact same liver inflammation, injury and failure sequence…just faster. In essence high fructose corn syrup should be regarded as energy source equivalent to that of alcohol with the same consequences and without the buzz. Its no mistake that most alcohols are made from naturally occurring sugars found in fruit, corn or wheat…fructose. Alcohol has specific neurotoxic side effects that help to limit consumption and toxicity. HFCS has no neurotoxic side effects. Therefore, consumption levels can be maintained without noticeable side effects. There are several other effects that alcohol shares with fructose including insulin resistance and metabolic syndrome.
Fortunately, fructose when absorbed in balance with glucose, as in cane sugar has a more favorable response profile in the liver limiting the amount of free radicals generated. Fructose when consumed in fruit comes with anti-inflammatory, free radical scavengers, like Vitamin C to counteract the deleterious effects of the fructose. Nature in harmony!
Hopefully, with this somewhat complicated understanding of normal human metabolism, you can make a better choice the next time you stop at a convenience store. Consider for one second, before you fill that 44oz drink with soda, if it were Jack Daniels coming out of that fountain, would you still drink it. I don’t ever advocate for drinking your calories, but if you have to have a soda, try to find one made with 100% cane sugar. I like the sodas imported from Mexico or the Hansen’s brand. Join me next month as we continue to explore the world of processed food.
Kevin Potter, D.O., GI Surgeon, St. Joseph’s Hospital and Medical Center, Phoenix, AZ
Link to Sugar: The Bitter Truth
, a video by Robert H. Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology, explores the damage caused by sugary foods. He argues that fructose (too much) and fiber (not enough) appear to be cornerstones of the obesity epidemic through their effects on insulin. Series: UCSF Mini Medical School for the Public.