As we age, biological processes occur in the body that impact health conditions. Scientists are working to understand the biological causes of aging in the hope of one day offering tools to slow or stop its visible signs.
These underlying mechanisms are often called "the hallmarks of aging" Many fall into two broad categories: general wear and tear at the cellular level and a decline in body's ability to eliminate old or dysfunctional cells and proteins. "If they are reversed, you can live longer or be healthier as you age," says Linda Partridge, research professor in the division of biosciences at the University of California, College of London. "It's a billion-dollar question," says Andrew Dillin, professor of molecular and cellular biology at theUniversity of California. "The only thing we know is that effectiveness decreases with age" "Why We Die: The New Science of Aging and the Search for Immortality" by Venki Ramakrishnan is published by Simon & Schuster, $16.99.