Sugar Toxicity: When Sugar Intake Turns Dangerous

Author: Gary Klingsberg, D.O.

Sugar is the general term for sweet-tasting carbohydrates which are composed of carbon, hydrogen, and oxygen. Ingredients to look for when reading labels include single molecules called monosaccharides such as glucose, galactose, ribose, and fructose; dual molecules or disaccharides such as sucrose and lactose and longer chain polysaccharides which compose starch. Table sugar is sucrose, a molecule which consists of glucose and fructose. Lactose, the sugar in milk, is a molecule which consists of glucose and galactose.

Some sugar is necessary for proper body function

Certainly, sugar in one form or another is essential to life. We could not live without it. Aerobic metabolism of glucose in the mitochondria produces most of the energy for cellular metabolism in the form of adenosine triphosphate (ATP) molecules. Ribose forms the backbone of DNA, our genes, as well as composing ATP energy molecules.

Too much sugar can be toxic

Like other substances that are essential to life, such as oxygen and water, too much can be as toxic and detrimental to health as can be too little. Dietary sugar has been increasingly linked to insulin resistance, diabetes, obesity, microvascular disease, heart disease, kidney disease and Alzheimer’s disease.

Diabetes, whether Type 1 due to a lack of insulin production, Type 2 due to systemic insulin resistance and elevated insulin levels, or the relatively recently coined Type 3 with elevated brain glucose and insulin resistance associated with Alzheimer’s disease, causes harm.

How does sugar toxicity occur?

Sugar toxicity can occur through the attachment of sugars to proteins in a process called glycation, damaging the proteins so they no longer work properly and forming what is called: Advanced Glycation Endproducts (AGEs). The AGEs work through impairment of the actions of insulin, resistance to insulin, impairment of mitochondrial function, generation of oxidative stress and triggering of inflammation to cause harm.

These various immediate actions of the formation of AGEs can trigger damage to organs throughout the body by harming the endothelial lining of our capillary microcirculation. (The capillaries supply oxygen and nutrients to the tissues and remove carbon dioxide and waste products.)

The process that damages capillaries over time, triggered by high blood sugar levels, may harm various organs. The heart may develop a gradual loss of function leading to congestive heart failure due to diastolic dysfunction. In the brain, areas of leukoaraiosis, (damage to white matter from small vessel disease) occurs, especially in the aging population. When neurofibrillary tangles and beta-amyloid (components in Alzheimer’s) are present, brain cell viability is compromised. In a high glucose diabetic state, the viability of the cells is further compromised, likely due to enhanced oxidative stress on their mitochondria.

Recommendations to reduce your risk of sugar toxicity:

  • Reduce the amount of sugar in your diet and;
  • If you have diabetes get it under the best control possible through a combination of a low sugar diet, regular exercise, and appropriate medications when necessary.