Harold Fromm
University of Arizona
http://home.earthlink.net/~hfromm
EVOLUTION, ECOLOGY, AND THE WESTERN DIET
With a Glance at Jared Diamond, Michael Pollan,
and Gary Nabhan
Our earliest primate precursors lived
25 million years ago, followed by various types of evolving apes until, 5 or 6 million
years ago, hominids split off from chimpanzees, our nearest relative. In those earliest
years, as they lived in trees and moved about the ground on all fours, our precursors were
foragers, almost total vegetarians, lacking the physiques and brains needed to
hunt anything more carnal than small animals over which they happened to trip. William
Calvin, in A Brain For All Seasons,
tells us that gorillas eat 50 pounds of vegetation a day to extract enough
calories from the super high-fiber diets their jaws evolved to handle. Not
until bipedal hominids became hunter-gatherers several million years ago did
their fodder-rich, calorie-poor diets begin to include sufficient protein to
promote brain growth, as a result of incorporating meat from hunting. With the
appearance of Homo sapiens several hundred thousand years ago, root digging and
soaking, primitive cooking, and eventually the start of farming (a mere ten
thousand years ago) gradually began to alter the hominid diet even further.
Today, even though gut length and
jaw size have shrunk, while brain size and complexity have increased, we are
still, according to evolutionary biologists, basically the offspring of twenty
million years of primate evolution. But as a result of settlements,
civilization, and farming, to which were added the manufacturing skills from
the industrial revolution, close to zero percent of today’s diet can be said to
be found in nature: our foods have all been changed through processing. Yet we
are still constituted for a high carbohydrate, moderate meat-eating diet. Our
precursors could eat meat only after a kill. There were no refrigerators and
freezers to stop rot and decay. Eat it now or do without! A binge stored body
fat for lean days ahead. Today’s daily binges of meats and carbs are another
story altogether.
Is it really possible, you may ask,
that just about all the foods we eat today did not exist for 99.9% of “our”
history? Yes. Except for a few wild raspberries you might find on a country
walk, or some wild mushrooms, or milk from a family cow, the foods we eat today
can be found only in a superfarm, a superfactory, or a supermarket.
Are these manufactured foods good
for us or bad? As a general principle, I would say that if they increase our adaptiveness, our survivability—that is, our health—they
are good. If they make us less adapted to survival, they are bad.
Today’s chief food culprit is not
carbohydrates, the dietary mainstay of 25 million years—it’s refined carbohydrates, which did not
exist until recently. Just what is a refined carb? It is a product of
technology, a food that has been extracted from a “whole food,” leaving behind
some of its most important nutrients. White flour (referred to as “wheat flour”
on the packages of bread and cakes) is
extracted from the whole grains of wheat (which yield “whole wheat flour”) ;
sugars are extracted from canes, beets, and corn (the last of which yields high
fructose corn syrup, a long bad story in itself). White rice is extracted from
brown rice. These refined carbs appear in almost everything eaten today: bread
(but not 100% whole grain bread), pasta (but not whole wheat pasta), cake,
cookies, ice cream, most cold (and some hot) breakfast cereals, sauces, chips,
candy and much more. Without the husks or germ or endosperm from the whole
food, these refined carbs digest so rapidly that you would need to have the
metabolism of a hyperactive teenager or run a marathon immediately after eating
them in order to burn up the sudden burst of energy. Fruit juices (extracted and
refined from whole fruit) are not much better than soda pop, a glass of apple
juice consisting mainly of 100 calories of sugar-water from several apples
instead of the sugar, fiber, and phytochemicals from one whole munched apple. Wine and beer,
of course, are refined carbs (juices extracted from fruits and plants), but
they offer compensatory benefits not obtainable from apple juice—and the report
on red wine is consistently positive for health. Unused, all this energy stores
as body fat for future use. (But if you eat this stuff again the next day,
there IS no future use. You store more fat for a starvation period that never
arrives.) Insulin resistance, diabetes,
obesity and much more are the consequences. Whole foods release their energy
slowly, giving you more time to use it up. And, of course, whole carbs have all
sorts of trace minerals and fiber that our systems have evolved to need, that
fill us up with fewer calories, and that today are believed to reduce the risk
of cancer and other diseases.
All the meats we eat are also manufactures.
Whereas hunter-gatherers caught wild animals that were low in body fat and muscular from running—tough
and chewy by current standards—today’s animals are raised in factories,
confined in pens, unable sometimes even to turn around. They are fed foods that
they mostly never ate before, such as corn, to fatten them up quickly without
muscle-toughening exercise (I won’t go into the drugs needed to enable their
systems to tolerate this food). They are high in saturated fat (bad). That’s
what all the “marbling” is about in prime meats, which fortunately have become
hard to find.
Yet there is a fat that’s even worse
for the arteries, heart, etc.: transfat, produced through hydrogenization
of liquid fats. It’s present in almost every manufactured cake, bread, candy,
cookie, coffee creamer and whatnot. (Though it’s not hard to avoid if you pay
attention.) All that Crisco and Spry—pure transfat so cozily peddled to our mothers as
“vegetable shortening” during our childhood—was just the beginning. Now it’s
everywhere.
As for vegetables, hunter-gatherers
would probably not recognize the ones we have today, which have been hybridized
for a long time and now are further altered by genetic engineering. In the
forty years during which I grew corn, for instance, the changes have been
drastic, as anyone who bought seeds from Burpee’s and
Gurney’s and Harris Seeds will recognize. Although there has been a bad side to
some of this, my personal opinion here is that vegetables are better than ever
and that we would find the veggies from our childhoods to be unappetizing and
limited in variety. What the foragers searched all day to find (expending most
of the calories from their last meal), we’d now regard as hog fodder.
Vegetables and minimally processed grains are probably our best bet today for
survival, supplemented with fish (hold the mercury!) and fowl (hold the
antibiotics!).
In sum, the standard diet of
industrialized nations is unsuited to our evolved constitutions. The sweet
tooth that once goaded us to search for
vegetation in the wilds now can be mega-gratified in five minutes by a brownie equal
to a week’s worth of sugar from foraging.
Three leading scholar-writers in
ecology and evolutionary biology have been shedding additional light on this core problem. In Guns, Germs, and Steel, Jared Diamond
connects ecology and diet with the development of settled communities and
civilization, explaining how the fortuities of environment and human
intelligence are responsible for the foods we eat today, foods selected from
myriad possibilities that were not as conducive to early modes of farming as
the ones that emerged as winners. Although yams, manioc, and millet, for
example, are still staples of non-Western diets, it is a handful of
early-cultivated grains and beans that have become the primal fodder of the
West, healthful at first but now degraded in the universally refined versions
that suit the needs of food manufacturers more than the health needs of the general population. As these monocultured crops destroy the topsoil while requiring more
and more pesticides, the knowledge of wild foods and natural products still
retained by the world’s few remaining hunter-gatherer societies slowly
disappears. Or as Diamond puts it, “This traditional knowledge gradually loses
its value and becomes lost, until one arrives at modern supermarket shoppers
who could not distinguish a wild grass from a wild pulse.”
The most powerful accounts I know of
what has happened to the Western diet and its ecology can be found in the
brilliant writings of Michael Pollan. In one of the
four essays of his entrancing book, The
Botany of Desire, Pollan provides background and
meaning to the 19th century dissemination of appletree
seeds by the legendary Johnny Appleseed. We learn
that every seed in an apple (unlike every bean in a pod) will produce a different type of progeny with
a different genetic character, so that grafting is the only way to produce new
trees true to the occasionally sweet parent. The consequence, to quote one of Pollan’s informants, is that “A century ago there were several
thousand different varieties of apples in commerce; now most of the apples we
grow have the same five or six parents.” What results from this, of course, is
a monoculture that breeds indigenous bugs with an evolved genetic makeup to
thrive on these few varieties. Only constant use of pesticides can control
them. Furthermore, to quote Pollan, “the
domestication of the apple has gone too far, to the point where the species’
fitness for life in nature . . . has been dangerously compromised,” reduced to
a “handful of genetically identical clones.”
In an even more striking series of
articles that Pollan wrote for the New York Times, high-tech commercial
domestication of foods is shown to produce consequences more dire. In his
shocking article “Power Steer”[1] Pollan describes his purchase of a newly born calf that he
consigned to a standard feed lot while tracking
its every stage as it was moved through the process leading to slaughter and
packaging as supermarket meat. The horrors are manifold but the exaltation of
corn feed by the combined power of the meat and agribusiness industries is especially
egregious. The ruminative stomachs of cattle, which evolved to digest grass from
grazing, are instead fed corn to fatten up bodies of meat that will be turned
into steaks and chops in a fraction of the free-range time. Corn makes the
cow’s rumen “unnaturally acidic, however, causing a kind of bovine heartburn,
which in some cases can kill the animal but usually just makes it sick,”
leading to a host of diseases, from ulcers to pneumonia and feedlot polio. The remedy, of course, is antibiotics, most
of which in America end up in animal feed, producing antibiotic-resistant superbugs along the way.
Pollan, in
“An Animal’s Place,”[2] has
a lot more to say about this as well as other forms of market-produced animal
cruelty. Surveying the spectrum of philosophical views of animals, he writes:
“Even vegans have a ‘serious clash of interests’ with other animals. The grain
that the vegan eats is harvested with a combine that shreds field mice, while
the farmer’s tractor crushes woodchucks in their burrows, and his pesticides
drop songbirds from the sky. Steve Davis, an animal scientist at Oregon State
University, has estimated that if America were to adopt a strictly vegetarian
diet, the total number of animals killed every year would actually increase, as animal pasture gave way to
row crops. Davis contends that if our
goal is to kill as few animals as possible, then people should eat the largest
possible animal that can live on the least intensively cultivated land:
grass-fed beef for everybody. It would appear that killing animals is
unavoidable no matter what we choose to eat.”
In
his brief article about corn, “When a Crop Becomes King,”[3] Pollan picks up on the feedlot corn diet to describe how
“our entire food supply has undergone a process of ‘cornification’”
through the efforts of giant agribusinesses such as Archer Daniels Midland,
ConAgra, and Cargill. Not only are we being force-fed corn via the guts of
factory raised animals, but high fructose corn syrup has become the most widely
used sweetener, added to more products than the average consumer realizes, from
the obvious soft drinks to every type of snack food and condiment. Of this
immense ingestion of sugar, Pollan remarks,” It’s
probably no coincidence that the wholesale switch to corn sweeteners in the
1980’s marks the beginning of the epidemic of obesity and Type 2 diabetes.”
Moreover, corn requires more nitrogen-based fertilizers and pesticides than any
other crop, as well as oil and natural gas to produce them, so the damage from
corn extends to both humans and the environment (though the “environment” is
ultimately us).
The subject of obesity and diabetes
leads us to Gary Nabhan, whose two most recent books
address these subjects directly. Why Some
Like it Hot, the newer of them, has
logical priority because it provides the theory whose practice had already been
worked out in the earlier book, Coming
Home to Eat. The theory, in a nutshell, is that the food needs of Homo sapiens are not just the product of their
Paleolithic past but of the indigenous cultures that have tweaked their genes
since that past. When members of these cultures leave their native habitats and
migrate to other parts of the world, puzzling infirmities often manifest
themselves along with the change in diet. Moreover, not even a migration is
needed—a cultural change that produces a
dietary change is a virtual migration that can be just as dire as a real one.
In the United States the increasingly Westernized diet of Native Americans has
produced the most extreme proliferation of diabetes. Nabhan, living in
Arizona and with many Indian friends, has
seen the consequences at close quarters. But as an ecologist, he also has an additional motive for addressing the refined
carbohydrate diet that precipitated this epidemic: the extraordinary amount of
energy—particularly fossil fuels—that is consumed to process and transport
foods of all kinds, even those considered healthful, from far away places (like
the Braeburne apples I buy imported from New
Zealand). The cumulative force of these various
motives led Nabhan to investigate the plausibility of
eating locally grown whole foods. Tossing cans and bags of junk or refined foods
from his larder into the trash he began to track down local farmers and
backyard vegetable growers in southern Arizona, largely an older generation, who still grew and consumed indigenous crops.
Not only did he begin to eat plants that most of us have never encountered as
food, he organized a band of about 180 Native Americans and Anglos to walk
several hundred miles across the Sonoran Desert of
Arizona, subsisting mainly on indigenous plants and animals, with a bit of
dietary help from friends along the route. Although largely symbolic, the aim
of this walk was to show that a return to a local, healthful, diet was still
possible.
But even Nabhan
had to admit that getting most of his friends to eat this food in their normal
daily lives was a hard sell. And to speak personally, apart from those mired in
poverty and primitive conditions, the dream of a return to an indigenous diet
seems highly implausible in a world of 6 billion people, many of whom have
reached a stage of unprecedented comfort and affluence—while others starve.
Those of us who come to conferences,
highly educated, mostly well off, living not far from a Trader Joe’s or a Whole
Foods or even an upscale Safeway are in
a privileged position to buy unrefined whole foods and maintain a healthful
diet, though it’s a diet that can not by a long shot be considered local. But
it’s hard to see how the intertwined dilemma of mass produced cheap refined
foods--triggering widespread obesity plus diabetes--and enormous consumption of
fossil fuels to process, package, and deliver them is going to be resolved in
the near future.