Why We Die: The New Science of Aging and the Quest for Immortality

This discerning study by Ramakrishnan (Gene Machine), a Nobel Prize–winning molecular biologist, examines the science of aging and efforts to stop it. Discussing the molecular processes that contribute to aging, he explains that the ends of chromosomes feature repeated genetic sequences, some of which are lost every time a cell divides until the replicated sequences have been exhausted. At that point, the cell stops dividing, reducing the body’s capacity to regenerate tissue. Ramakrishnan demonstrates a healthy skepticism when surveying attempts to extend human life, suggesting that while some animal studies indicate calorie-restricted diets and transfusing younger individuals’ blood into older patients might slow aging, there’s not yet enough evidence that these strategies would work for humans. The author has a knack for making biology accessible (“You can think of damage to mitochondria from oxidation as a case of our cells rusting from within”), and he brings a searching philosophical sensibility when considering the wisdom of seeking to extend life, cautioning that “a greatly extended life span would deprive our lives of urgency and meaning, a desire to make each day count.” The result is a strikingly pensive exploration of how bodies decline and whether efforts to slow that process are worth the cost. (Mar.)