1) Modern chronic diseases like diabetes, heart disease, and Alzheimer's are increasingly prevalent, costly to treat, and largely preventable through lifestyle changes rather than just medical treatment of symptoms. 2) These "diseases of civilization" have emerged with the agricultural and industrial revolutions and are mismatched with our evolutionary biology due to poor diets and lack of physical activity. 3) While medicine has focused on curing infectious diseases, it has been less effective at preventing chronic diseases and their rising rates through the generations by not emphasizing lifestyle and environmental factors.

1. By any historically informed appraisal, 21st
century life is pretty pleasant for most of us. We live
longer and grow larger than our recent ancestors.
Our offspring survive childhood and adolescence at
an unprecedented rate. We are also more comfort-
able and have more choices than the richest kings
or queens of old.
But are we healthier? As you read this article,
you are likely seated in a position your body never
evolved to assume. You might be nibbling a muffin or
donut with your morning coffee, or perhaps sipping a
sugary soda with lunch. When you lower the maga-
zine, how long will it take for your eyes to adjust? Do
you wear thick-soled shoes—perhaps with arch sup-
ports—to protect your sensitive feet?
Statistically speaking, most of us suffer from at
least one malady our hunter-gatherer forebears rarely
experienced. Are you significantly overweight, for ex-
ample? What about your children? How many of your
neighbors, friends, relatives, and co-workers don’t have
a problem with allergies, asthma, cavities, flat feet, low
back pain, myopia, or insomnia? Few if any, I’ll wager.
On average, each American spends about $8000
per year on healthcare—in total, nearly 18 percent of
the nation’s gross domestic product. And most of that
hard-earned money is frittered away on the treatment
of completely preventable illnesses, including type II
diabetes, some cancers, and heart disease.
Modern medicine has succeeded brilliantly in
eradicating most of the infectious diseases that began
plaguing our species in the wake of the agricultural
revolution. Today, however, we suffer and die from an
entirely different spate of post-agricultural and post-
industrial ailments. These are the infamous “diseases
of civilization” that now account for 80 percent of
American healthcare spending. They are projected to
cost the global economy $47 trillion over the next 20
years, and to kill twice as many people as all infec-
tious diseases combined.
But both intuition and conventional wisdom in-
vite us to expect as much. We now live exceptionally
long lives, as noted. And immortality was never an
evolutionary option—we have to die of something, if
not contagion or malnutrition. So, perhaps chronic
diseases are better characterized as the inevitable ill-
nesses of extended old age, in some cases genetically
programmed to eventually wash us away in the wake
of our reproductive prime.
Not according to John Ratey, associate professor
of psychiatry at Harvard Medical School.1
He describes
type II diabetes, for example, as a “screaming, wailing
siren of a warning to our society that something is
changing fast, and that we ought to do something
about it.” Indeed, diabetes is a now-common metabolic
disorder that used to be quite rare. While it’s true that
genetics play a role in terms of susceptibility, biological
inheritance alone seldom explains the disease. Why is
the incidence rate of diabetes now higher in Asia than
in America, for instance? The answer is not that Asians
are getting older. In fact, what was once referred to
as “adult-onset” diabetes is now quickly spreading to
younger adults and children. Nor is it true that they
have evolved some new diabetes gene or genes. Rather,
Asians are suffering because they have lately adopted
with great and regrettable enthusiasm the typical West-
ern diabetogenic lifestyle marked by poor dietary
habits and physical inactivity.
Harvard evolutionary biologist Daniel Lieberman
recognizes the self-inflicted, environmentally-based
origins of diabetes.2
But he also sees the problem of
rising incidence rates as one of many unfortunate ex-
amples of chronic disease “dysevolution” (harmful
change over time). Modern medicine is not only inef-
fective at addressing chronic diseases, he insists, but,
in combination with cultural apathy, it actually makes
them more prevalent from one generation to the next
by failing to focus on prevention rather than the mere
treatment of symptoms.
20 SKEPTIC MAGAZINE volume 19 number 4 2014
ARTICLE
An Evolutionary and
Functional Perspective
on Chronic DiseaseBY Kenneth W. Krause

2. First, doctors and patients seldom even try to ad-
dress such problems until the latter get sick. Second,
doctors usually prescribe only modest weight loss and
exercise regimens because they believe their patients
will either ignore more challenging and effective ad-
vice, or simply fail in its attempted execution. Finally,
physicians tend to prescribe anti-diabetes drugs, like
metformin, that are far less effective than healthful
lifestyle changes (and often involve unpleasant side
effects). Thus, we unwittingly perpetuate and even
accelerate the cycle of chronic disease by resigning
ourselves to the clumsy management of symptoms
and, in the end, to failure.
Consider as well tooth decay, a causally related
but very different and far simpler “mismatch” disease.
Cavities were rare among hunter-gatherers and occur
relatively infrequently among non-human apes. But
they spread through the post-agricultural human pop-
ulation like wildfire and, today, afflict nearly 2.5 bil-
lion people. Why? Again, the excessively sugar-laden
and starchy diets now pervading Western culture are
inimical to our evolved biology.
And what has been our medical response? A
strategy informed by both genomics and natural his-
tory would dictate serious revisions to dietary habit.
Nevertheless, we still consume cereals and processed
grains—i.e., cheap calories—by the bucket-load. So,
instead, we’ve decided to brush and floss day after
day, and to hire hygienists and dentists to scrape,
drill, fill, and replace our teeth as they are slowly
eaten away by bacteria that ironically did evolve to
dine on refined sugars.
So, as we emphasize technical innovation and
symptom treatment—i.e., palliative dental care—
over a preventive approach based on evolutionary sci-
ence, we trigger Lieberman’s dysevolutionary
feedback loop. To our children, we relay a predomi-
nantly cultural strategy, allowing the disease to not
only persist, but perhaps also increase in both preva-
lence and intensity as the generations pass.
Along with obesity and heart disease, diabetes
and tooth decay perhaps epitomize chronic diseases
resulting from environmental excess—that is, overuse.
Others, however, stem from individual disuse. For ex-
ample, asthma and other immune-related disorders—
the incidences of which have tripled since the 1960s
in wealthy nations—may result from our recent obses-
sion with cleanliness and, thus, underexposure to cer-
tain germs and worms. Flat feet and plantar fasciitis
can afflict people whose foot muscles have weakened
due to over-reliance on shoes with stiff soles, heavy
cushioning, or arch supports. Focusing our eyes too
long on close objects can elongate our eyeballs and
DIET SCIENCE
volume 19 number 4 2014 WWW.SKEPTIC.COM 21

3. cause myopia, or nearsightedness. Sitting in comfort-
able chairs and hunching over desks can cause hip and
leg muscle imbalances producing lower back pain.
And how do we typically confront these afflictions?
We treat the symptoms only, with drugs, orthotics,
eyeglasses, and, perhaps worst of all, bed rest.
A debilitating bone disease, osteoporosis, demon-
strates how age, sex, hormones, exercise, and diet in-
teract to define the later stages of life. This mismatch
disease of disuse was exceedingly rare among seniors
until very recently. Today, however, it causes more
than one-third of elderly women in America to frac-
ture their bones.
Skeleton growth is maximized by age 20 in
women and 25 in men. Thereafter, bone mass de-
clines as osteoclast activity begins to outpace that of
osteoblasts. Throughout most of life, estrogen serves
to minimize damage to women. Following
menopause, however, degeneration accelerates as
hormone levels plunge. Low blood calcium levels also
allow osteoclasts to resorb bone tissue.
But just as children can build larger, stronger
bones with increased activity, older adults can slow,
perhaps even halt or reverse, the degenerative
process with vigorous and consistent weight-bearing
exercise. We can also replace calcium-deficient,
grain-based diets with more appropriate foods packed
with calcium, vitamin D, and protein. Instead, we are
often prescribed estrogen supplements or drugs to
slow osteoclast activity. Once again, however, the side
effects of such treatment can prove unpleasant, even
to include increased risks of heart disease and cancer.
It is absolutely true that certain forms of early-
onset Alzheimer’s disease are strongly associated with
genetic inheritance. Contrary to popular opinion,
however, 95 percent of all documented Alzheimer’s
cases—i.e., those afflicting people over the age of
60—are not primarily genetic in origin.
According to Jeffrey Bland, biochemist and co-
founder of the Institute for Functional Medicine, the
infamous ApoE4 gene does not by itself cause
Alzheimer’s.3
Rather, it merely “describes a suscepti-
bility to the disease that the individual’s choices of
lifestyle and diet can affect.” In other words, inheri-
tance of ApoE4 simply increases susceptibility “to the
dangerous effects of diets high in saturated fat and
sugar and of a sedentary lifestyle.”
Bland insists that “new paths of inquiry and re-
search” into Alzheimer’s reveal an extended list of
major environmental risk factors entirely within our
preventive control—diet, chronic inflammation, in-
sulin resistance, elevated blood levels of homocys-
teine, poor exercise tolerance, lack of brain
stimulation, and exposure to toxic substances. More-
over, he suggests, medical interventions addressing
these factors, especially diet, can improve brain func-
tion in patients already suffering from the illness.
The landscape of disease has changed dramati-
cally in recent years. A recent worldwide study meas-
ured years lost to both premature mortality and
diminished health.4
Between 1990 and 2010, the
greatest spike in disability resulted from heart dis-
ease, stroke, depression, and metabolic diseases like
diabetes—all of which are avoidable to varying de-
grees through serious environmental and lifestyle
changes. The incidences of ischemic heart disease
rose 29 percent (jumping from the number four to
the number one ranking), while rates of stroke and
depression increased 19 and 37 percent, respectively.
As a society and as individuals, we clearly pay
woefully inadequate attention to disease prevention.
One large-scale, long-term, and well-controlled study
found that sedentary American men who subse-
quently improved their fitness levels halved their rates
of cardiovascular disease.5
According to Lieberman, it
costs $18,000 per year to treat one case of heart dis-
ease. Thus, persuading just twenty-five percent more
Americans to meet national fitness guidelines could
save more than $58 billion per year for care related to
heart disease alone. This figure equals roughly twice
the annual research budget of the National Institutes
of Health (of which only five percent is allocated to
disease prevention).
As Bland warns, our current yet outdated med-
ical infrastructure and education system remain
geared toward the “pill-for-an-ill” treatment of conta-
gious diseases and acute events. As such, they are ill-
suited to addressing the complexities of those chronic
illnesses that constitute today’s predominant health
reality.
22 SKEPTIC MAGAZINE volume 19 number 4 2014
1. Ratey, J. and R. Manning. 2014. Go Wild: Free Your
Body and Mind from the Afflictions of Civilization.
NY: Little, Brown and Company.
2. Lieberman, D. 2013. The Story of the Human Body:
Evolution, Health, and Disease. NY: Pantheon Books.
3. Bland, J.S. 2014. The Disease Delusion: Conquer-
ing the Causes of Chronic Illness for a Healthier,
Longer, and Happier Life. NY: HarperCollins.
4. Murray, C.J., T. Voss, R. Lozano, et. al. 2012. Dis-
ability-adjusted life years (DALYs) for 291 diseases
and injuries in 21 regions, 1990-2010; a system-
atic analysis for the Global Burden Disease Study
2010. Lancet 380(9859): 2179-223.
5. Blair,S.N.,H.W.Kohl, C.E. Barlow, et.al. 1995. Changes
in physical fitness and all-cause mortality: a prospec-
tive of healthy and unhealthy men. Journal of the
American Medical Association. 273(14): 1093-98.
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