It afflicts every creature on this planet, and everyone dreams of an antidote. But even after decades of research, aging largely remains a mystery. Now new research findings suggest there is a good reason for this impasse: scientists may have been thinking about the causes of aging all wrong. Instead of being the result of an accumulation of genetic and cellular damage, new evidence suggests that aging may occur when genetic programs for development go awry.
The idea that stress and reactive forms of oxygen—“free radicals” that are the normal by-products of metabolism—cause aging has dominated the field for 50 years. Studies on the worm Caenorhabditis elegans have shown that reducing exposure to reactive oxygen species increases life span, and worms that have been bred to live longer are also more resistant to stress. But few studies have definitively linked oxidative damage to altered cellular function.