Our bodies are the same as they were 315.000 years ago

Our bodies are anatomically and biologically the same as the bodies of the first homo sapiens humans who appeared 315.000 years ago. Their bodies (which means our current bodies) had evolved to stay healthy under the stimuli and constraints of their lifestyle. This also means their bodies needed these stimuli to develop and grow healthily.

Since then, the human body hasn’t evolved much, though it did evolve on the margin, mainly through positive selection of genes enabling us to cope with the new stimuli associated with farming (lactase persistence for instance).

From this, we can draw two consequences:

• any stimuli we subject our body to, which was not applied to it 315.000 years ago, is new and foreign and by default impacts our health negatively because our bodies have not evolved to cope with them. Some new stimuli won’t have a negative impact purely by chance, but most will, especially those applied for extended period of times (sitting, wearing high heels every day, etc.).
• any stimuli which existed at that time and which is not provided to our body in our modern lifestyle has a negative impact on our health, because our bodies evolved to develop and age in the presence of certain stimuli. If we don’t provide these to our body, some mechanisms start breaking down and health declines (obesity, diabetes, lack of mobility, etc.)

Understanding what the stimuli the human body evolved to cope with

The first step towards improving our health then, is to understand the lifestyle of the early homo sapiens and the stimuli applied to their bodies. I will call them “evolutionary stimuli” because these are the stimuli to which our bodies adapted to through evolution.

We can group them into 3 areas: physical, nutritional, environmental. Here are their main characteristics:

• Physical: high volume of daily walking (15-20km), at times loaded with weight to carry, and occasional runs and sprints, good amount of tree climbing for both activities. High degree of ground movements, object manipulation with the hands, loading and carrying small weights. Some sprints and other high intensity moves. Lots of rest positions but not much sitting around. Very high baseline of total physical activity per day and very high diversity of movements.
• Nutritional: there wasn’t one diet specific to these early homo sapiens, rather, there were several according to their regions. But there were commonalities: very high volume of fibers, very low volume of sugar in all its forms (simple or complex, fructose, glucose, etc.), it contained meat/fish, with the whole bodies being consumed, so incorporating all the fat, all the nutrition from organ parts. One important factor is that hunting/gathering enough food every day required important physical activity expenditures.
• Environmental: everything that is not physical or nutritional but is impacting our bodies comes from the environment. For example, hunter-gatherers lived in small nomadic groups (100-150 individuals) and raised their kids as a group. This means communicable diseases were kept in check due to the small size of the group (they exploded only when homo sapiens invented agriculture and large permanent settlements appeared) and sleep for new parents was much less an issue than it is today since all newborns were likely cared for as a group with duties rotating within the tribe.

I will concentrate below on the Physical and Nutritional domains, as they are the ones we can more easily control.

Current standard Western lifestyle

Our current lifestyle has been shaped by the technological innovations of farming first, and then of the industrial age and the rise of specialization, convenience and sedentariness. This means that our bodies are now subjected to both an explosion of new stimuli and a radical decrease in the evolutionary stimuli that are so beneficial to them.

An explosion of new stimuli with negative health impact

Industrial age stimuli can be characterized as such:

• Physical: high volume of sitting (home, office, car, train, plane, etc.), very high sedentariness, wearing highly constraining footwear, walking on concrete, etc.
• Nutritional: bulk of diet made up of processed foods bearing little semblance with the foods eaten 315.000 ago, fresh fruits and vegetables are much more sweet than the wild fruits and tubers foraged by the early homo sapiens, etc.
  The appearance of these new stimuli is associated with negative health outcomes, as our bodies do not manage to cope well with these entirely new (from an evolutionary perspective) stimuli.

Huge decrease in evolutionary stimuli that are necessary to maintain good health

Not only do we subject our bodies to negative, foreign stimuli, we deprive them of the positive stimuli they need to develop and age healthily. These are the stimuli notably absent from our standard modern lifestyle:

• Physical: very low level of daily activity, most of it time-bound and specialized (think sports training or even generic fitness sessions), close to no hanging in particular, low diversity of movement, especially the hands and on the ground, etc.
• Nutritional: very low level of chewing needed compared to evolutionary stimuli, little fiber as wild species were much more fibrous, lower vitamin levels and overall nutrition gained from diet, etc.

Modern medicine hid this trend for a while but that is ending

This sounds logical enough, but at this stage, the first question most people ask is “Wait a minute, how come life expectancy has increased so much recently, then?”.

The exact answer is a bit more complex, but what happened in the past 100 years or so is that modern medicine enabled us to solve many issues that impacted the average life expectancy. It has been extraordinarily efficient at preventing and treating communicable diseases and birth mortality, along with all the traumatic injuries being treated by surgery.

Unfortunately, that didn’t prevent these stimuli from being detrimental and since medicine is making less progress now (it solved a lot already), the underlying trends are emerging. With obesity and diabetes rates steadily rising in most of the world, their effects are being noticed more clearly. Already, life expectancy is decreasing in the US, and it won’t be long for other modern developed nations to follow, as well as emerging nations, since diabetes are exploding in some of these countries.

What’s more, average life expectancy has improved compared to the life expectancy of 300 years ago, 1000 years ago or even 10 000 years ago. When we compare it, we always compare it to the life expectancy after humans transitioned from hunting/gathering to farming. All the evidence available point to the fact that life expectancy decreased after the invention of farming, even though populations exploded.

What can we do?

Option 1: do nothing – standard Western lifestyle

As we’ve just seen, if your goal is to be and remain healthy in fit for the long-term, aging while maintaining your physical capabilities and decreasing your probabilities or getting sick, then doing nothing is not an option.

If we pursue with the same standard Western lifestyle, our health will follow the average trends: declining life expectancy, increasingly early disabilities and older days that will in all probability be less than fulfilling.

Option 2: go back to a caveman lifestyle

A radical option would be to go back to the early Homo Sapiens lifestyle, which is to say live as a cavemen were. That would actually work for our general health, but:

• the adjustments needed in terms of lifestyle are radical.
• that may not even be possible in today’s environment, since you’d need to find an isolated but resourceful stretch of land untouched by civilization.
• you’d need to forsake the benefits of modern medicine.

That’s not for me and probably not for you either.

Option 3: evolutionarily optimized lifestyle

A better option would be to adjust our modern lifestyle to take out as much of the industrial stimuli as possible, while increasing the evolutionary stimuli.

In terms of nutrition, that means avoiding processed foods, grains & sugar mostly, along with choosing the optimal options for other choices.

In terms of physical activity, that means both increasing the volume of it as much as possible and again choosing the best activities to get these evolutionary stimuli in.