Aging may be associated with a higher accumulation of cell damage resulting from reactive oxygen species and nitrogen derived from mitochondrial metabolism. With aging, there is an accumulation of proteins, lipids, carbohydrates and DNA oxidation in relation to young bodies, according to the theory of free radicals. However, not always the elderly or aged animals have higher oxidative stress than younger people. This paper discusses the paradox of the free radical theory according to the theory of biogenesis of proper maintenance of mitochondrial metabolism. Several factors may contribute to the reduction of oxidative stress, such as hormesis induced by regular physical exercise, calorie restriction, dietary intake of antioxidants and increased production of cellular antioxidants. Together, these promote the expression of sirtuins and heat shock proteins, protecting the integrity and mitochondrial function by reducing oxidative and nitrosative stress, which is associated with reduced aging and increased longevity.
Aging; Oxidative stree; Nitrosative stress; Mitochondria; Hormesis; Physical exercise; Antioxidants
