A significant portion of the North American population does not consume adequate zinc. Approximately 10% of the US population consumes less than half the recommended level for zinc.96 Importantly, zinc deficiency results in an increased sensitivity to oxidative stress97 and may, in part, account for the mechanism by which zinc deficiency increases the risk for cancer development. There is now increasing evidence that oxidative stress plays an important contributing factor in several chronic degenerative diseases such as cancer.98 Zinc's anti-oxidant function may be related to several factors. First, zinc is an essential component of CuZnSOD, one of the cell's first lines of defense against reactive oxygen species (ROS), which functions to remove the superoxide anion. Zinc is also an important factor in regulating metal-lothionein metabolism. Metallothionein, a small molecular-weight protein, is important in zinc homeostasis and has potent anti-oxidant activity. Zinc can induce the expression of the cysteine-rich metallothionein protein that acts as a potent scavenger of hydroxyl radicals. Loss of this protein can impair cellular anti-oxidant defenses and contribute to the cell's sensitivity to oxida-tive stress. Other potential mechanisms for zinc's anti-oxidant effects are the antagonism of redox-active transition metals, such as iron or copper, and the prevention of oxidation of sulfhydryl groups within proteins. Zinc can limit hydroxyl radical formation from H2O2 by competing with both iron and copper in Fenton reactions and appears to stabilize sulfhydryl groups in
Compromised zinc status clearly has a significant impact on anti-oxidant capacity of the cell. Several laboratories, including our own, have shown increased oxidative stress with zinc deficiency. Increased oxidant production has been shown in zinc-deficient cell cultures105 and increases in oxidative protein and DNA damage have been shown in zinc-deficient rats.87,95,97,106,107 Zinc-supplementation strategies have also been shown to be beneficial against oxidant damage and the progression of ROS-induced diseases such as diabetes.49,108 Addition of zinc also protects cells from UV-induced DNA damage and apoptosis.109,110 In humans, zinc supplementation appears to help patients with slowing the progression of AMD.111,112 Thus, the anti-oxidant role of zinc could be an important mechanism in maintaining DNA integrity in the cell by preventing oxidative DNA damage in the cell.
Reactive oxygen species are commonly produced during normal cellular metabolism. However, under certain conditions of stress, such as poor nutrition, an increase in the production of ROS may overwhelm host anti-oxidant defenses, resulting in oxidative damage. There is increasing evidence that the pathology and disease development associated with oxidative stress may not be due simply to increases in oxidative damage.113 Rather, ROS may also act as signaling molecules that trigger distinct pathways to induce pathology. Thus, the role of zinc deficiency in the development of chronic diseases such as diabetes and cancer may be far more complex than simply causing oxidative damage. Instead, zinc status may also affect redox-sensitive signals and ultimately alter signal pathways involved in stress response and DNA repair.
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All you need is a proper diet of fresh fruits and vegetables and get plenty of exercise and you'll be fine. Ever heard those words from your doctor? If that's all heshe recommends then you're missing out an important ingredient for health that he's not telling you. Fact is that you can adhere to the strictest diet, watch everything you eat and get the exercise of amarathon runner and still come down with diabetic complications. Diet, exercise and standard drug treatments simply aren't enough to help keep your diabetes under control.