Antioxidant Defense System

Although zinc is not itself an antioxidant, there are several ways in which it participates in the antiox-idant defense system of the body, with important implications for health. It can bind to thiol groups in proteins, making them less susceptible to oxidation. By displacing redox-reactive metals such as iron and copper from both proteins and lipids it can reduce the metal-induced formation of hydroxyl radicals and thus protect the macromolecules. Its role in inducing MT has already been mentioned, and this protein scavenges hydroxyl radicals. Increased oxidative stress results in the release of zinc from MT, presumably making it more available for other proteins. Copper/zinc superoxide dismu-tase is an important zinc-containing antioxidant enzyme whose activity is impaired in the deficient state. In general, animal studies have revealed an association between zinc deficiency and increased oxidative stress. The likelihood of increased oxida-tive stress under conditions of zinc deficiency suggests a potential anticarcinogenic role for this mineral. This connection is further supported by the finding that the tumor suppressor gene p53, which is frequently mutated in human cancers, is a zinc-containing transcription factor whose expression is also dependent on zinc.

Breaking Bulimia

Breaking Bulimia

We have all been there: turning to the refrigerator if feeling lonely or bored or indulging in seconds or thirds if strained. But if you suffer from bulimia, the from time to time urge to overeat is more like an obsession.

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