Fructose, Glucose and the Danger of Glycation Reactions

Based in Waterbury, Connecticut, Dr. Rex Mahnensmith is an internist who practices with StayWell Health Center. Having lectured extensively on issues such as kidney disease, Dr. Rex Mahnensmith authored the article “Glucose Becomes A Toxic Molecule in Prediabetes and Diabetes.”

Focusing on an element of diet typically consumed in starchy plants such as corn, potatoes, yams, wheat, and rice, Dr. Mahnensmith describes chain-bound glucose as distinct from sucrose, which chemically combines fructose and glucose within a two ­molecule compound. Sucrose is found in numerous fruits, vegetables, and other plants, including beets and sugarcane. 

When ingested, sucrose is split into its fructose and glucose components. The glucose is rapidly absorbed through the intestinal tract to the bloodstream and provides a ready energy source for a variety of tissue and cell functions. This process takes less than a day and results in cells stocking up with energy that is either consumed through activity or stored for future use as glycogen starch.

By contrast, fructose is not absorbed readily. In cases where it is bonded with cellulose, it passes through the intestinal system and is finally eliminated. In cases of bloodstream absorption, it enters the liver and is turned into fat cells that serve as an “energy depot of last resort” when glycogen starch is used up by the body 

Where glucose becomes harmful - and often serves as an indicator of prediabetes - is when it is not transported to tissue cells efficiently. Oxygen and other circulating reactive molecules ultimately cause the glucose molecules to undergo a molecular structure change while still in the bloodstream, leading to random glycation reactions that impact tissue and organ structures adversely.