Metabolic Syndrome

Oxidative Stress and Insulin Resistance

Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. Disturbances in the normal redox state of cells can cause toxic effects through the production of peroxides and free radicals that damage all components of the cell, including proteins, lipids, and DNA. Oxidative stress from oxidative metabolism causes base damage, as well as strand breaks in DNA. Base damage is mostly indirect and caused by reactive oxygen species (ROS) generated, e.g. O2− (superoxide radical), OH (hydroxyl radical) and H2O2 (hydrogen peroxide). Further, some reactive oxidative species act as cellular messengers in redox signalling. Thus, oxidative stress can cause disruptions in normal mechanisms of cellular signalling.

Insulin resistance (IR) is a pathological condition in which cells fail to respond normally to the hormone insulin. To prevent hyperglycemia and noticeable organ damage over time, the body produces insulin when glucose starts to be released into the bloodstream from the digestion of carbohydrates (primarily) in the diet. Under normal conditions of insulin reactivity, this insulin response triggers glucose being taken into body cells, to be used for energy, and inhibits the body from using fat for energy, thereby causing the concentration of glucose in the blood to decrease as a result, staying within the normal range even when a large amount of carbohydrates is consumed. A habitually high intake of carbohydrates, simple sugars, and particularly fructose, e.g. with sweetened beverages, contributes to insulin resistance and has been linked to weight gain and obesity. If high and excess blood sugar from the digestion of primarily carbohydrates in the diet is not sufficiently absorbed by cells even in the presence of insulin, the increase in the level of blood sugar can result in the classic hyperglycemic triad of polyphagia (increased appetite), polydipsia (increased thirst), and polyuria (increased urination). Avoiding carbohydrates and sugars, a no-carbohydrate diet or fasting can reverse insulin resistance