What causes aging? “Scientists have been thinking about this question for centuries,” says Harvard professor of medicine Vadim Gladyshev. It sounds almost simple, but in fact it’s thorny and complicated, and although several theories have emerged—that organisms are “programmed” by nature to die, or that aging is the result of “hyperfunction” of biological activities, or that it’s controlled by genetics—there are as yet no settled answers. But a study published today in Science Advances, coauthored by Gladyshev, offers evidence bolstering one long-held theory: that aging is caused, at least in part, by molecular damage accumulating in the cells. “This damage is generated by nearly every cellular process,” he says—by the work of enzymes and proteins and the life-sustaining metabolic processes that occur at every level of complexity, from simple molecules and cell components to whole cells and entire organs. “So over time we have many, many ‘damage forms,’ millions or billions”—unavoidable byproducts of enzyme function, for example, or of protein-to-protein interactions, errors in DNA transcription or translation. “And as a function of age, they accumulate.” Eventually, it’s more than the body can cope with.
…“Aging is the most important biological question.” It is at the root of so many diseases. “Even if we eliminate cancer, for example, the effect would be minor, because of all the other diseases of aging: diabetes, Alzheimer’s, sarcopenia, cardiovascular disease, and so on and so on.” All of those maladies will still add up. “But if we can learn how to slow down the aging process, we can deal with all of those diseases at once. We delay their appearance. That’s why it’s important to study these fundamental questions, to ask: what is aging?”
