Nutrición y envejecimiento / Nutrition and aging

RESUMO

Genetic and environmental factors influence the process of aging. Longevity is extraordinarily constant along species and there are several genes that regulate it. Special consideration deserve apoprotein E alleles, specially allele eee4 that is associated with development of Alzheimer disease, atheroesclerosis and a shorter life. However environmental influences on longevity are of utmost importance. In rats, mice and non human primates, caloric restriction prolongs life and retards the appearance of several conditions associated with aging. This effect of caloric restriction is probably due mainly to a reduction in the generation of primary and secondary reactive oxygen species. Noteworthy is the reduction of DNA oxidative damage and the consequent reduction in transcriptional defects. Telomeres, special structures located in the extremes of chromosomes, are specially susceptible to oxidative damage. This structures have been postulated to act as biological clocks of cells, since their progressive shortening is a signal to stop replication. In humans, telomeres shorten throughout life and in some diseases associated with premature aging such as trisomy 21 and Werner syndrome, the loss of telomeric bases occurs at a higher rate. The knowledge about environmental influences on aging will allow us to increase our life span and to reduce the disabilities associated with aging