EXTRA LIFE

A surprising look at why humans are living longer.

Author of a dozen lively, informative books on science and technology, brain and body, Johnson begins his latest with an intriguing fact: In just one century, the human species has doubled its life expectancy. Wondering why, he set out to investigate the forces that led to such a dramatic improvement. As in his previous books Where Good Ideas Come From and How We Got to Now, Johnson argues convincingly that critical changes occur not from the endeavors of lone geniuses but from a network of researchers, activists, reformers, publicists, producers, and marketers. The discovery of penicillin, for example, has generated a mythical tale about Alexander Fleming, who noticed, in an overlooked petri dish, that a layer of mold happened to have killed bacteria. The reality, Johnson reveals, was far more complex: “For penicillin to graduate from a brilliant accident to a true miracle drug, three things needed to happen: someone had to determine whether it actually worked as a medicine; someone had to figure out how to produce it at scale. And then a market had to develop to support that large-scale production.” In tracing particular life-threatening diseases, such as cholera, tuberculosis, and smallpox, Johnson examines breakthroughs that have had overarching significance in extending life expectancy: vaccines; advances in data collection; the invention of epidemiology, pasteurization, and chlorination; the advent of regulations and testing of drugs; antibiotics; improved safety technology and regulations; and the development of modern soil science. The author points to randomized, controlled double-blind trials, involving a network of investigators and participants, as crucial in proving the efficacy of any new drug; and to international, multidisciplinary collaboration involved in disseminating treatments. Global eradication of smallpox, he asserts, “was as dependent on the invention of an institution like [the World Health Organization] as it was on the invention of the vaccine itself.”

Entertaining, wide-ranging, and—in light of Covid-19—particularly timely.