Book Review: The Story of the Human Body by Daniel Lieberman
The Story of the Human Body by Daniel Lieberman, Published: 2014, London, Penguin Books
I’m a late-comer to this book, having read it nine years after it was published in 2014. However, its content resonates so strongly with me that I decided to share my thoughts. I’ve long believed that making informed decisions about diet and lifestyle is only possible with a perspective from evolutionary history. This book makes that case.
The book is well written, accessible to lay-people like me and very enjoyable. It is divided into three sections. The first section covers pre-Neolithic history and focuses on bipedalism and metabolism. The second section covers the last 12,000 to 15,000 years of modern human development since we emerged from widespread glaciation (Holocene) and went on to create the agricultural and industrial revolutions. The third section takes from the first two to develop the theme of evolutionary mismatch in the development of modern chronic diseases.
“…farming may be one of the greatest unnatural practices ever developed.”
In the second section he shocked me by observing that farming may be one of the greatest unnatural practices ever developed. Incredibly, people became smaller and less healthy when they drifted away from hunting and gathering 10,000 years ago.
The third part of the book is the most relevant for me. Lieberman discusses human bodily dysfunction, and presents it mainly as a problem of "mismatch” between our bodily evolution and our cultural evolution. He argues that many of us suffer from things like obesity, type-2 diabetes, heart disease, tooth decay, flat feet, nearsightedness, lower back pain, and sleep disorders because our cultural evolution has outpaced our biological evolution. In essence, he is saying that the agricultural and industrial revolutions allowed us to live longer than ever before but we spend many of those years in a state of chronic, preventable suffering.
“…chewing (sugar free) gum is good for children because their teeth and jaws need the exercise that modern diets have eliminated.”
Lieberman describes humans as biological generalists, not designed to do one thing really well (e.g., speed, strength, sensory acuity) but adaptable to many situations. However, our core healthy biological functions exist within a somewhat narrow margin of error. This can result in some interesting and maybe counter-intuitive realities. For example, I wish I’d known years ago that chewing (sugar free) gum is good for children because their teeth and jaws need the exercise that modern diets have eliminated. Thankfully I did know that fresh fruit juices are as unhealthy as high sugar soft drinks because they spike our blood insulin. It's always better to eat fresh fruit with its natural fibre.
In chapter 11 Lieberman discusses the human microbiome, but only briefly and in the context of the hygiene hypothesis. I suspect that if he reviewed the subject of the human holobiont today he could add a fourth section to the book. We should be so lucky!
“For millions of years, humans struggled to stay in energy balance, but billions of people are now obese from eating more calories (especially from massive doses of sugar) as well as from less physical activity. As we accumulate excess fat in our bellies while fitness dwindles, diseases of affluence are on the rise, especially heart disease, type 2 diabetes, osteoporosis, breast cancer, and colon cancer.”
A series of quotes from the book brought everything home for me. My favourite is on page 167 - “…considering and knowing about evolution in general, and human evolution in particular, is indispensable for preventing and treating a class of diseases and other problems known as evolutionary mismatches.” Toward the end of the third section (p. 349) he states “The principal trade-off between the novel environments we have created and the bodies we inherited has been mismatch diseases.” Also “For millions of years, humans struggled to stay in energy balance, but billions of people are now obese from eating more calories (especially from massive doses of sugar) as well as from less physical activity. As we accumulate excess fat in our bellies while fitness dwindles, diseases of affluence are on the rise, especially heart disease, type 2 diabetes, osteoporosis, breast cancer, and colon cancer.”
I found this book fascinating and hopeful. Fascinating because it helped me to clarify a hunch about diseases of poor nutrition that I’ve long held, that they are caused by eating processed food ingredients to which we are not adapted. Hopeful because now I know those diseases can be at worst stabilized and likely reversed, as with type 2 diabetes, with real food and a healthy lifestyle.
About the author
Daniel Lieberman is Professor in the Department of Human Evolutionary Biology, and the Edwin M. Lerner II Professor of Biological Sciences at Harvard University. He is also a member of Department of Organismic and Evolutionary Biology. He was educated at Harvard (AB ’86 Summa cum Laude, PhD ’93) and Cambridge (M.Phil. ’97). His research is on how and why the human body is the way it is, and the relevance of human evolution to contemporary health.