Book Review: What Is Health?

Can our neuroscientific history redefine health during a pandemic?

Posted Apr 14, 2020

Gordon Johnson/PIxabay
Source: Gordon Johnson/PIxabay

What is Health? Allostasis and the Evolution of Human Design by Peter Sterling (MIT Press) was released in February 2020, just as COVID-19 was unfolding. Written in response to the epidemics of overconsumption that were already killing us, this book was urgently needed before the coronavirus pandemic and holds even more pressing relevance now.

Allostasis, a term coined by Sterling and Joseph Eyre in the 1980s, captures just how dynamically our neural and physiological systems learn, anticipate, coordinate, and adapt to change to the pinnacle of maximum efficiency. Well beyond the negative feedback loop system of homeostasis, Sterling explains why we seek novelty and challenge, and how our systems then strengthen to meet new demands. He redefines health as the capacity to respond optimally to fluctuations in demand and employs us to see with clear eyes how health is something to restore, not manage.

The preface and introduction set the scene of Sterling’s own life and what has led to this story of humans in the full context of how our ability to adapt and change is what keeps us alive. The journey started in the 1960s when Sterling observed the high rate of undiagnosed stroke in the poorest black communities of Cleveland, Ohio. Social injustice, he observed, has everything to do with health (inequalities highlighted again since the onset of COVID-19). From there, the story goes back 4 million years.

This non-fiction biological history book enlightens first-year medical students, yet easily enthralls a casual curious reader. Opening to a roughly 200-page tour over billions of years might feel like you bit off more than you can chew but hang in there. It isn’t dry or too academic. Sterling wraps in just enough juicy detail how Homo sapiens have become what we have: sophisticated, social, and ever-evolving.

This evenly-paced story up to the present day starts with a single cell that has increased in complexity via trade-offs that prove to be optimal. It steadily builds to reveal how a systems approach of inclusivity is necessary for our collective health.

How we get to understand disease as social brokenness from here may seem impossible, but he does it. Sterling admits that science itself grows and changes and the story may unfold differently over time to be told another way, but for now this is how he tells it based on evolution through the wide awake lens of allostasis. Each chapter employs intriguing examples that build curiosity about the next evolutionary step.

The stages in between are most surprising: Why did tissue-specific cells emerge? Why does DNA replicate at night? Why did Homo sapiens start outsourcing heat and digestion by cooking with fire? Lactation, endothelial cell function, smooth muscles, folds in the gut and brain, the hypothalamus – each development is elucidated, generally jargon-free, and well-referenced.

Case & Deaton, 2017
Source: Case & Deaton, 2017
Wilkinson & Pickett, 2009
Source: Wilkinson & Pickett, 2009

Sterling answers the question, "what is health?" and a few others, like "what do we really need?" and "what do we need right now to survive epidemic deaths of despair including drug and alcohol abuse, food and material overconsumption, addictions, and climate change?" 

But before answering, he explains the role of limb development and the impulse to move, gather, and hunt. This, of course, followed by the sedation of settlements leading to the development of culture – and with it, less sharing and the eventuality of rich and poor parts of town.

Are we helpless against fighting our own nature of evolving to how we are now? Yes. And no. It’s hard to tell exactly what our evolutionary history will reveal about us next and what the possibilities are for collective wellness as we wind through this highly unlikely tale of our evolutionary history.

Could change happen overnight? Maybe. He points to historical moments of executive orders such as Truman in the 1940s for the desegregation of transit workers. Perhaps if we need more proof, we can look at this past month of shelter-in-place orders that have shifted our consumption of nearly everything.

A single thing that would help everyone? Reducing inequality. How? You might be tempted to peek ahead to the last chapter. I did. You will still want to go back to understand the stages in between marines worms and you, now.

The book begins and ends with questions about Homo sapiens that allow us to reflect on ourselves deeply. Referencing Oliver Sack’s story of the lost mariner, Sterling says, “We are all mariners in constant danger of being lost at sea.”  We are all trying to understand what tethers us and share the potential to be unmoored. A simple mechanistic approach won’t help us live an integrated life. By the end, we understand how and why culture developed: art, music, dance, sacred practices, and even forgiveness. Sterling helps us see why these are necessary to help us get along with each other, why tolerance isn’t enough. We are led to a prescription to seek joy and appreciation of the ordinary and ever-deepening appreciation for diversity to live in better health and harmony.

What is Health? leaves us with a sense of how urgent it is we adapt and change course now as well as a bit of a cliff-hanger of our uncertain future. Will humans realize their collective error in time enough to change it or “fold into the fossil record?"