According to the biochemical hypothesis that links consumption of high fructose corn syrup to auto-immune reactivity and asthma, conditions in the small intestines of fructose malabsorbers may promote antigen formation. The exact mechanism proposed is the same as that which occurs in high fructose conditions in the blood stream of diabetics. What is thought to occur is a reaction between elevated fructose and dietary proteins known as the Maillard reaction. This reaction may result in dietary protein fragments becoming modified and digestion resistant. Once absorbed in the blood stream they may give rise to the auto-immune, respiratory distress, chronic bronchitis and asthma symptoms observed. Research is needed to test this hypothesis. The exact mechanisms that are responsible for the observed link between consumption of high fructose corn syrup and activation of the immune system remain unknown.
It is thought that fructose malabsorption is a condition that underlies the link between high fructose corn syrup and auto-immune reactivity, chronic respiratory distress and asthma. Lastly, very few natural foods contain fructose to glucose in ratios consistent with what independent laboratories have found when analyzing high fructose corn syrup containing foods. Apples, watermelons, and pears are notable exceptions. But we generally don't eat the amounts of these natural foods to reach the doses scientists observed as triggering fructose malabsorption symptoms. For example, to consume 30 grams daily of excess-free-fructose you would need to eat about 8 - 10 apples or a twelve pound watermelon per day. How likely is that? Not likely.
In 2008, a team of researchers at Rutgers State University of New Jersey found high levels of highly reactive intermediate products of the Maillard reaction known as dicarbonyl compounds in all non-diet carbonated beverages they tested (Tan, Wang, Lo, Sang, and Ho, 2008). These compounds are known to interact with proteins or peptide fragments to form what researchers refer to as advanced glycation end-products (AGEs) and their presence has been found to be elevated in the blood stream of diabetics as compared to non-diabetics. More and more evidence indicates that the increase in reactive dicarbonyl intermediates is a consequence of hyperglycemia in diabetes. Dicarbonyl stress leads to increased modification of proteins, followed by oxidant stress and tissue damage (Tan, Wang, Lo, Sang, and Ho, 2008). These bio-molecules are thought to contribute to the development of diabetes mellitus and its complications. For example, damage by the contaminants found in the soda to low-density lipoproteins (LDL - "the bad cholesterol") through a reaction referred to as glycation causes a fourfold increase in the formation of plaques in the lining of arteries (Rabbani et al., 2011). In experiments by Tan et al., of all non-diet sodas tested, they were able to identify high fructose corn syrup as the major source of methylglyoxal (MG), a well characterized, highly reactive dicarbonyl of the Maillard reaction (Tan, Wang, Lo, Sang, and Ho, 2008).