How humanity doubled life expectancy in a century

Summary

In this TED Talk, Steven Johnson discusses how human life expectancy has doubled in the past century. He says that as best we can measure, the average global life expectancy one hundred years ago stood somewhere in the mid-30s. Today, it's just over 70. So in just one century, we have doubled global life expectancy. Even in 1950, around one-third of the Earth's human population had a life expectancy below 45. Fast-forward to today, and very few countries have a life expectancy below 60. Johnson sometimes says the increase in life expectancy is considered a statistical illusion due to the huge reduction in infant mortality. And while there is some truth to that, there is much more to the story. Other reasons for our increase in life expectancy include:

Vaccines. Smallpox, polio, influenza, tuberculosis (TB), measles (and now COVID-19) vaccines have saved countless lives, increasing lifespan.

Milk. Johnson describes milk as 'one of the most terrifying threats of the 19th century'. Milk was a serious health threat, particularly to children, because of a lack of refrigeration. People continued to get TB from milk until pasteurization became commonplace.

Pharmaceutical drugs. These previously contained various poisons, including arsenic, mercury, heroin and cocaine. Pharmaceutical drugs were a negative in terms of human health until the invention of antibiotics in the 1940s.

Johnson believes that instead of extending life even further, scientists should now focus on reducing the health gap around the world. Transcript available here.