A conversational, intelligent look at the current understanding of how and why biological aging occurs, along with some suggestions for how to stay healthy in old age. British gerontologist and World Health Organization advisor Kirkwood challenges two commonly held ideas about aging: first, that it is inevitable (“because we just have to wear out”), and second, that it’s necessary (because if some of us don’t die, the world will become “hopelessly crowded”). The truth is infinitely more complicated, and Kirkwood, in a comfortable, entertaining, but not oversimplified style puts readers straight on what is currently known about the aging process at the cellular and higher levels. Along the way, he looks at related issues of interest: what goes wrong with the body when cancer occurs (and how cancer interacts with aging), the meaning and mechanisms of menopause, why eating less may mean living longer, why women continue to live longer than men, and what part genetics plays in longevity (says Kirkwood, “Length of life is influenced by many things, including purely random factors like car accidents”). Kirkwood is an amiable, intelligent guide at the forefront of a fast-changing field. His is an entertaining and informative look at our current understanding of aging.