Why We’re Living Longer but Getting Sicker

The Story of the Human Body

Most of us don’t sit around thinking about the human body’s evolution. And that’s a main reason we’re living longer but suffering ill health along the way. At least that’s the reason outlined by Harvard University evolutionary professor Daniel Lieberman, who puts it all on the table in his book The Story of the Human Body. He outlines how modern man typically mistakes comfort for well-being, and many of the things that make us comfortable are also eroding our health.

Take a gander at a speeded-up evolutionary snapshot and you’ll see why. Humans went from hunting and gathering their food while walking an average of 5 to 9 miles per day to spending the bulk of their day sitting around. Whether we’re in a chair, in a car or on the bus, the average modern man walks less than one-third of a mile per day.

Why It’s Happening

We can largely blame the Industrial Revolution for the massive changes in the way we work, eat and get around town. And we can blame what Lieberman terms mismatch diseases and dysevolution as the reasons we continue to fall prey to disabilities and illnesses.

Mismatch diseases are illnesses that rarely affected earlier humans but hit us hard because our bodies are not well-adapted to the modern environment our culture has created. Hunter-gatherers were not prone to the back pain many modern folks get, for instance, since they were consistently on their feet, keeping their back muscles strong.

Mismatch diseases largely come into play when our bodies encounter stimuli that are “too much, too little, or too new.” Too much starch, too little exercise and certain novelties that apparently make our life easier backfire to make our bodies weaker and susceptible to problems.

Lieberman coined the term “dysevolution” to explain what’s happening in the bigger picture. Unlike a biological evolution that occurs when we pass down genes to our offspring, dysevolution takes place when we continue to engage in and pass on the behaviors and environments that give rise to mismatch diseases.

He uses high blood pressure as a dysevolution example, noting that we know how to lessen its risk. But instead of increasing exercise, decreasing stress and eating healthier foods to decrease its risk, many instead reach for medication as a cheaper and quicker fix.

How We Make It Worse

While medication may lower blood pressure, it’s doing nothing to amend the activities or environment that created the condition in the first place. Then we pass on those same behaviors and factors to the next generation who, not surprisingly, end up suffering from high blood pressure. Treating symptoms instead of root causes of mismatch diseases ensures the dysevolution process continues, and the diseases remain prevalent or even increase in their severity and scope.

We can also make it worse without even realizing it by reducing certain stressors the body needs at an early age to develop in the manner we’re supposed to. We have major control over a baby’s environment, subjecting them to toxins, foods or even temperatures that play a major role in their development.

The Solution

Being in the know about what’s happening is a start, but knowledge means nothing without action. And eating healthy foods, getting adequate amounts of exercise and avoiding activities that contribute to mismatch diseases may be easier said than done. Here’s where motivation needs to kick in, as does a positive change in our environment to help prevent, rather than perpetuate, the illnesses that are killing off our health and quality of life.


Lieberman D. The Story of the Human Body: Evolution, Health, and Disease. New York, NY: Pantheon; 2013.