Within the last twenty years the view on reactive oxygen species (ROS) has changed; they are no longer
only considered to be harmful but also necessary for cellular communication and homeostasis in different
organisms ranging from bacteria to mammals. In the latter, ROS were shown to modulate diverse
physiological processes including the regulation of growth factor signaling, the hypoxic response, in-
flammation and the immune response. During the last 60–100 years the life style, at least in the Western
world, has changed enormously. This became obvious with an increase in caloric intake, decreased energy
expenditure as well as the appearance of alcoholism and smoking; These changes were shown to
contribute to generation of ROS which are, at least in part, associated with the occurrence of several
chronic diseases like adiposity, atherosclerosis, type II diabetes, and cancer. In this review we discuss
aspects and problems on the role of intracellular ROS formation and nutrition with the link to diseases
and their problematic therapeutical issues.
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