Dirt
Eirik
G
na
ar
s
A
A MISSING COMPONENT
OF THE MODERN DIET
s Paleo dieters know, some food
groups are healthier than others.
However, it could be argued that
factors such as preparation methods,
processing techniques, pasture fed
versus grain fed, or full fat versus low fat
are in some ways even more important
than which food groups you eat—as long
as you stick with a whole-foods dietary
template, of course. This might sound
a bit exaggerated, but if we look at how
healthy human populations around the
world have eaten, it quickly becomes
clear that we are an extremely adaptable
species. Non-modernized cultures have
thrived on everything from diets very high
in carbohydrates to almost exclusively
meat-based diets.1,2
The primary differences between
the foods that were consumed in nonmodernized, traditional cultures and those
we eat in today’s Westernized world are
that isolated, healthy populations—such
as those studied by Dr. Weston A. Price—
ate food of extremely high quality, and
they put far more emphasis on processing
and preparing their food correctly, using
techniques such as lacto-fermentation
to make grains, legumes, fruits and
vegetables more shelf stable and easier
to digest.
The transition from traditional to
modern food is clearly visible when
you take a trip through your local
grocery store. Kefir made from raw,
grass-fed, full-fat milk fermented with
real kefir grains has been replaced
with kefir made from pasteurized,
homogenized, grain-fed, fat-reduced
milk fermented by the use of a starter
culture; sourdough oatmeal bread is
replaced with massive amounts of wheat
products; and animal products from wild
and pasture-fed animals are replaced
with meat from livestock that have been
raised on unnatural food and injected
with hormones and antibiotics. I’m
exaggerating to make a point, as most of
6 September 2015 eNewsletter
us do have access to food that is more in
line with the types of foods we’ve eaten
throughout most of our evolutionary
history. However, when we look at the
world’s population and the modern food
environment as a whole, it’s clear that
we’ve largely disconnected ourselves
from the past.
So, to find a healthy eating pattern,
we can’t simply discuss which food
groups we should include in our diet; we
habitat of one of the last hunter-gatherer
communities on earth, the Hadza.
Although most of the Hadza people have
now transitioned over to a more modern
lifestyle, there are still some who stick to
the old ways of doing things. They gather
honey when possible, do persistence
hunting to chase down prey, and eat
fruits, vegetables and berries that are
available in the wild. Although not a
perfect imitation of the African Paleolithic
man, these people give us a glimpse of
how our prehistoric ancestors lived.
There are many things we can learn
from the Hadza, one being that an
ancestral African lifestyle often includes
massive exposure to microbes. When the
Hadza men are out hunting, women spend
their time digging for underground storage
organs. Although not as highly valued as
meat and honey, tubers rich in prebiotic
fibers are relatively easy to gather, and
they constitute a large part of the Hadza
diet. These women definitely get their
hands dirty—a “dirtiness” that seems to
be one of the characteristics of the Hadza
lifestyle. As Jeff Leach of the Human Food
COMPARED TO RELATIVELY RECENT INTRODUCTIONS
TO THE HUMAN DIET, SUCH AS CONTROLLED LACTOFERMENTED FOODS AND SOAKED AND SPROUTED GRAINS,
THE DAILY INGESTION OF DIRT IS AS ANCIENT AS CAN BE.
also have to look at the hints evolution
gives us about other aspects of human
nutrition. This brings us to the topic of
today’s article. When most people think
about eating healthfully, soil and bacteria
are usually not the first things that come
to mind—but I’ll argue that they should
be. We’ve already discussed briefly how
food quality, preparation and preservation
methods, and processing techniques
have changed since the pre-industrial
days. There’s another transition that might
be just as important, but typically receives
little attention—the transition from eating
“dirty” food to eating “clean” food.
Our Dirty Ancestors
Compared to relatively recent
introductions to the human diet, such
as controlled lacto-fermented foods and
soaked and sprouted grains, the daily
ingestion of dirt is as ancient as can be.
In the Paleolithic era, hunter-gatherers
lived in close contact with the natural
environment, and hand sanitizers,
shampoo, washing machines, bar soaps
and large apartment buildings were
nowhere to be found.
Let’s for a moment diverge far from
the modern world, into the African
Project has reported, the Hadza even eat
the intestines of the animals they kill, and
sometimes “wash” their hands with the
stomach contents. This behavior really
highlights the difference between microbial
exposure in an ancestral environment and
in the modern world.
It’s simply impossible to avoid getting a
daily dose of dirt through your diet when
you rarely wash your hands, dig up and
eat tubers with clinging soil, and generally
live in close proximity to nature. One
might suspect that these behaviors would
lead to frequent infections and increased
mortality rates, but what the data show is
that although infants in hunter-gatherer
populations can be vulnerable to certain
parasites and other pathogenic microbes
they pick up from the environment, the
general theme is that dirt is good for us.3,5
At least, that is, “old dirt.” Because
this is really where the problem lies.
In the modern world, factors such as
pollution, conventional farming methods
and widespread use of biocides have
changed the soil microbiome, and for
people living in less-developed countries,
the combination of malnutrition, dysbiosis
and exposure to pathogens can
sometimes be deadly.