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Malocclusions and Urolithiasis
in the Context of
Evolutionary Medicine
Giacinto Libertini
[email protected]
www.r-site.org/ageing
www.programmed-aging.org
Preamble
What is Evolutionary
Medicine?
Evolutionary or Darwinian
Medicine [1-6] comes into
being in 1991 [1], but there
are
some
known
forerunners [7] (e.g. [8]) and
others not generally cited as
forerunners [9,10].
[1] Williams GC, Nesse RM (1991) The dawn of Darwinian medicine. Quart. Rev. Biol. 66, 1-22.
[2] Nesse RM, Williams GC (1994) Why we get sick. New York (USA), Times Books.
[3] Stearns SC (ed) (1999) Evolution in health and disease (1st ed.). Oxford (UK), Oxford University Press.
[4] Trevathan WR, Smith EO, McKenna JJ (eds) (1999) Evolutionary Medicine. New York (USA), Oxford
University Press.
[5] Trevathan WR, Smith EO, McKenna JJ (eds) (2008) Evolutionary Medicine: new perspectives. New York
(USA), Oxford University Press.
[6] Stearns SC, Koella JC (eds) (2008) Evolution in health and disease (2nd ed.). Oxford (UK), Oxford
University Press.
[7] Trevathan WR, Smith EO, McKenna JJ (2008) Introduction and overview of Evolutionary Medicine. In:
Trevathan WR, Smith EO, McKenna JJ (eds) Evolutionary Medicine: new perspectives. New York (USA),
Oxford University Press.
[8] Eaton SB, Shostak M, Konner M (1988) The paleolithic prescription: a program of diet & exercise and a
design for living. New York (USA), Harper & Row.
[9] Price WA (1939) Nutrition and Physical Degeneration. New York – London, Paul B. Hoeber.
[10] Libertini G (1983) Ragionamenti Evoluzionistici. Naples (Italy), Società Editrice Napoletana; English
Edition (2011): Evolutionary Arguments. Crownsville (USA), Azinet Press.
Evolutionary Medicine is not an
Alternative Medicine
(like homeopathy, iridology, ayurvedic
medicine, naturopathy, traditional
Chinese medicine, energy medicine, etc.)
but a Medicine that is
more thoroughly scientific
In that it involves the concepts of
Evolutionism.
A medicine that ignored the principles of
chemistry, for example, would be partially
scientific.
Similarly, a medicine that ignores
the principles of evolution
is partially scientific.
So the contrast is not between:
Current Medicine
Alternative Medicines
but between:
Current Medicine
(which in most cases
ignores Evolutionism)
Evolutionary Medicine
(which is a more thoroughly
scientific medicine)
However, the first practical question is immediate:
Is this difference only a theoretical / verbal nicety?
or
Has this difference strong and significant implications
for the structure of medical studies and for health organization?
Evolutionary Medicine involves many concepts and
applicative consequences.
Here, I develop a practical application of a simple
concept, the “mismatch” [1,2], to the genesis of
malocclusions and of urolithiasis.
The concept of “mismatch” is simple but with
huge implications:
If a species is adapted to a certain range of
conditions
(including
diet,
environmental
conditions, interrelations with other living beings,
etc.), called for brevity “ecological niche”, any
change in the ecological niche potentially is a
source of disfunctions (diseases), because there is
no adaptation to the new conditions.
This is defined as "mismatch”.
[1] Eaton SB, Shostak M, Konner M (1988) The paleolithic prescription: a program of diet & exercise and
a design for living. New York (USA), Harper & Row.
[2] Libertini G (2009) Prospects of a Longer Life Span beyond the Beneficial Effects of a Healthy
Lifestyle, in: Bentely JV, Keller MA (eds) Handbook on Longevity: Genetics, Diet & Disease, New York
(USA), Nova Science Publishers Inc.
Malocclusions and Urolithiasis
in the Context of Evolutionary Medicine
Step 1 - Epidemiological study
of modern populations
For Malocclusions:
In USA: “Noticeable incisor irregularity occurs in the
majority of all racial/ethnic groups, with only 35% of
adults having well-aligned mandibular incisors.
Irregularity is severe enough in 15% that both social
acceptability and function could be affected, and major
arch expansion or extraction of some teeth would be
required for correction.” [1]
In a study on Peruvian children: “The prevalence of
malocclusions was 85.6%” [2]
…
[1] Proffit WR et al. (1998) Prevalence of malocclusion and orthodontic treatment need in the United
States: estimates from the NHANES III survey. Int. J. Adult Orthodon. Orthognath. Surg. 13, 97-106.
[2] Aliaga-Del Castillo A et al. (2011) [Malocclusions in children and adolescents from villages and native
communities in the Ucayali Amazon region in Peru] [Article in Spanish] Rev. Peru Med. Exp. Salud
Publica 28, 87-91.
Step 1 - (CONTINUED)
…
A study on Tanzanian children showed that 63.8 per cent of
the subjects had at least one type of anomaly [1].
For Urolithiasis:
“The overall probability of forming stones differs in various
parts of the world: 1-5% in Asia, 5-9% in Europe, 13% in
North America, 20% in Saudi Arabia.” [2]
Among 20- to 74-old United States residents nephrolithiasis
incidence increased from 3.8% in the period 1976-1980 to
5.2% in the period 1988-1994 [3].
“Recent data provide evidence that the incidence of
nephrolithiasis in children is rising.” [4]
“Pediatric urolithiasis has increased globally in the last few
decades.” [5] …
[1] Mtaya M et al. (2009) Prevalence of malocclusion and its relationship with socio-demographic factors,
dental caries, and oral hygiene in 12- to 14-year-old Tanzanian schoolchildren. Eur. J. Orthod. 31, 467-76.
[2] Ramello A et al. (2000) Epidemiology of nephrolithiasis. J. Nephrol. 13, S45-50.
[3] Stamatelou KK et al. (2003) Time trends in reported prevalence of kidney stones in the United States:
1976-1994. Kidney Int. 63, 1817-23.
[4] Sas DJ. (2011) An update on the changing epidemiology and metabolic risk factors in pediatric kidney
stone disease. Clin. J. Am. Soc. Nephrol. 6, 2062-8.
[5] Sharma AP, Filler G. (2010) Epidemiology of pediatric urolithiasis. Indian J. Urol. 26, 516-22.
Step 1 –
(CONTINUED)
…
“There has been considerable
increase in the incidence of
idiopathic renal stone in
Europe,
North
America,
Australasia and Japan within
the
present
century
(Grossmann, 1938; Inada et
al., 1958; Andersen, 1969; Fig.
4.1)” [1]
[1] Trowell HC, Burkitt DP (eds) (1981). Western diseases, their emergence and prevention. Edward Arnold,
USA.
Step 2 - Comparison between the frequency of a disease in modern
populations and the frequency of the same disease in populations
in primitive conditions
For Malocclusions:
“Although previous studies of primitive Eskimos have
reported practically no malocclusion, 82 per cent of the
children in this study had malocclusions.” [1]
“It is a matter of great significance that the Eskimos who
are living in isolated districts and on native foods have
produced uniformly broad dental arches and typical
Eskimo facial patterns. Even the first generation forsaking
that diet and using the modern diet, presents large
numbers of individuals with marked changes in facial and
dental arch form” [2]
“… from 25 to 75 per cent of individuals in various
communities in the United States have a distinct
irregularity in the development of the dental arches and
facial form … In a study of 1,276 skulls of these ancient
Peruvians, I did not find a single skull with significant
deformity of the dental arches.” [2] (see fig. on the right)
…
Figure 78 from [2]
[1] Barry FW (1971) Malocclusion in the modern Alaskan Eskimo. Amer. J. Orthod. 60, 344-54.
[2] Price WA (1939) Nutrition and Physical Degeneration. New York – London, Paul B. Hoeber.
Step 2 – (CONTINUED)
…
Seminole Indians using native (left, fig. 24) and modernized (right, fig. 25) foods. “Note the
change in facial and dental arch form in the children of this modernized group.” [1] …
[1] Price WA (1939) Nutrition and Physical Degeneration. New York – London, Paul B. Hoeber.
Step 2 – (CONTINUED)
…
“Another
important
source
of
information regarding the Aborigines of
Australia was provided by a study of the
skeletal material and skulls in the
museums at Sydney and Canberra,
particularly the former. I do not know
the number of skulls that are available
there for study, but it is very large. I
examined many and found them
remarkably uniform in design and
quality. The dental arches were
splendidly formed.” [1]
“Note the marked difference in facial and
dental arch form of the two Samoan
primitives above and the two modernized
below.
The
face
bones
are
underdeveloped below causing a marked
constriction of the arches with crowding
of the teeth.” Comment to fig. 36 (on the
right) from [1]. …
[1] Price WA (1939) Nutrition and Physical Degeneration. New York – London, Paul B. Hoeber.
Step 2 - (CONTINUED)
… Price, in his irreproducible work, documented in many parts of the world (in people now
completely modernized, but in 1939 divided into groups living in primitive conditions and
others with more or less advanced degree of civilization) very different rates of tooth decay
depending on the degree of diet modernization. In populations living with a natural diet, the
set of teeth was well-formed, the bones of the face well developed, and the teeth practically
free from caries. By contrast, in populations with modernized diets, the set of teeth was
disordered, the face underdeveloped and tooth decay widespread, and all these alterations
were proportional to the degree of diet modifications. [1] …
Figures 17 (left)
and 19 (right)
from [1]
[1] Price WA
(1939) Nutrition
and
Physical
Degeneration.
New
York
–
London, Paul B.
Hoeber.
Step 2 - (CONTINUED)
...
For Urolithiasis:
“Renal stone is rare among persons living in poor or primitive socio-economic
circumstances and is very rare in African Bantu living under tribal conditions (Modlin,
1969)” [1]
“To summarize, from being virtually unknown in historical times, renal stone has become
significant as a common morbid condition in the affluent, westernized countries within the
last 80 years whilst remaining rare in communities where the people live in primitive and
poor conditions.” [1]
Epidemiological data strongly contrast the possible hypothesis that the high
frequencies of malocclusions and urolithiasis suffered by modern populations are
caused by a recent (in evolutionary terms) relaxation of natural selection
pressures.
On the contrary, they indicate that these diseases are largely due to alterations of
the ecological niche to which our species is adapted, that is presumable
phenomena of mismatch.
[1] Trowell HC, Burkitt DP (eds) (1981). Western diseases, their emergence and prevention. Edward
Arnold, USA.
Step 3 - Hypotheses on the possible changes in the ecological niche
underlying the disease and on possible pathogenetical mechanisms
Price, in his fundamental work [1], not surprisingly called Nutrition and Physical
Degeneration, attributes the high frequency of malocclusions (and of other dental diseases)
to changes in diet and lifestyle compared with the habits of primitive societies.
A critical factor emphasized by Price is the amount of dietary vitamin D and of sun
exposure for the formation of additional vitamin D. According to Price, an insufficient
intake and absorption of dietary calcium in the early years of life determines, among other
things, insufficient development of facial bones and an improper development of the set of
teeth.
Konner and Eaton [2] reported that prior to 1990 the recommended daily intake of vitamin
D was 400 IU and that of calcium 800 mg. In 2010, this advice had become 1000 IU of
vitamin D and 1000 mg of calcium. But the estimate for the ancestral population was over
4000 IU of vitamin D (also by sunlight) and 1500 mg of calcium. It is clear that with regard
to ancestral conditions there is a strongly reduced intake of dietary calcium and a
considerable deficiency of vitamin D, a poorly understood problem even in scientific circles.
…
[1] Price WA (1939) Nutrition and Physical Degeneration. New York – London, Paul B. Hoeber.
[2] Konner M, Eaton SB (2010) Paleolithic Nutrition: Twenty-Five Years Later. Nutr. Clin. Pract. 25, 594602.
Step 3 – (CONTINUED)
…
But if malocclusions are largely caused by reduced intake of dietary calcium and by
reduced intake and production of vitamin D, these factors could seem to cause a reduced
frequency of urolithiasis, a thing that is clearly contradicted by data from modernized
population.
However, it has been shown that urolithiasis frequency is inversely related to dietary
calcium intake [1-3], even though supplemental calcium may increase the risk [2].
Dietary calcium reduces oxalate absorption and the urinary excretion of oxalate and this
lowers the risk of kidney stones of calcium oxalate, the prevalent type of stones [1]. This
“may be due to increased binding of oxalate by calcium in the gastrointestinal tract” [1].
Other factors correlated with a lower frequency of urolithiasis are potassium intake [1]
and fluid intake [1].
The intake of fiber and plant foods reduces urinary calcium excretion and thus the
frequency of the stones, while carbohydrate intake has the opposite effect [3].
A higher protein intake is associated with a moderate increase of urolithiasis risk [1].
…
[1] Curhan GC et al. (1993) A Prospective Study of Dietary Calcium and Other Nutrients and the Risk
of Symptomatic Kidney Stones. New Engl. J. Medic. 328, 833-8.
[2] Curhan GC et al. (1997) Comparison of dietary calcium with supplemental calcium and other
nutrients as factors affecting the risk for kidney stones in women. Ann. Intern. Med. 126, 497-504.
[3] Heller, HJ (1999) The role of calcium in the prevention of kidney stones. J. Am. Coll. Nutr. 18, 373S378S.
Step 3 – (CONTINUED)
It is essential to compare the ancestral diet with that of contemporary Western populations [1].
In the table, the factors in the modern diet that increase urolithiasis risk are highlighted in pink, while those
having the opposite effect are highlighted in green. It is not shown in the table the reduced intake of calcium in
modern diets that is strongly correlated with urolithiasis frequency.
Total energy intake
Caloric density
Dietary bulk
Total carbohydrate intake
Added sugars/refined carbohydrates
Glycemic load
Fruits and vegetables
Antioxidant capacity
Fiber
Soluble:insoluble
Protein intake
Total fat intake
Serum cholesterol-raising fat
Total polyunsaturated fat
ω-6:ω-3
Long-chain essential fatty acids
Cholesterol intake
Micronutrient intake
Sodium:potassium
Acid base impact
Milk products
Cereal grains
Free water intake
Ancestral (Hunter-Gatherer)
More
Very low
More
Less
Very little
Relatively low
Twice as much
Higher
More
Roughly 1:1
More [N.B.: lean, from game]
Roughly equal
Less
More
Roughly equal
More
Equal or more
More
<1
Alkaline or acidic
Mother’s milk only
Minimal
More
Contemporary Western
Less
High
Less
More
Much more
High
Half as much
Lower
Less
<1 insoluble
Less [N.B.: fat, from breeding]
More
Less
Far more ω-6
Less
Equal or less
Less
>1
Acidic
High, lifelong
Substantial
Less
[1] Konner M, Eaton SB (2010) Paleolithic Nutrition: Twenty-Five Years Later. Nutr. Clin. Pract. 25,
594-602.
Step 4 - Study of the mechanisms linking
the alteration of the ecological niche to
the pathogenesis of the disease
For malocclusions
The proper development of facial bones and set of
teeth is optimal when the values ​of dietary calcium
and of vitamin D absorption and production are
those to which our species is adapted.
Modernized alimentation has severely altered
these factors, and perhaps others that are more or
less important to a correct development.
The details of these alterations and the
mechanisms by which the correct development is
compromised require further information and
explanations, but the correlation between
alterations in diet and lifestyle and the correct
development of facial bones and set of teeth are
clear and well documented for a long time past [1].
[1] Price WA (1939) Nutrition and Physical Degeneration. New York – London, Paul B. Hoeber.
Step 4 – (CONTINUED)
…
For urolithiasis
There is hypercalciuria in 95% of patients with nephrolithiasis [1].
The mechanism by which hypercalciuria causes an increased risk of renal stones is known
[2].
There are foods that reduce calcium absorption, and therefore the urinary calcium - K, PO4,
fiber, Alkali Load alias fruits and vegetables - and others that have the opposite effect –
supplemental Ca, Na, Mg, Carbohydrates, Acid Load alias animal flesh - and the
mechanisms that cause these effects are quite known [2].
But an increase in dietary calcium reduces oxalate absorption and oxalate excretion in the
urine and thus reduces the frequency with which they form calcium oxalate stones, the most
common type of calculations [3].
[1] Levy FL et al. (1995) Ambulatory evaluation of nephrolithiasis: an update of a 1980 protocol. Am. J.
Med. 98, 50-9.
[2] Heller, HJ (1999) The role of calcium in the prevention of kidney stones. J. Am. Coll. Nutr. 18, 373S378S.
[3] Curhan GC et al. (1993) A Prospective Study of Dietary Calcium and Other Nutrients and the Risk of
Symptomatic Kidney Stones. New Engl. J. Medic. 328, 833-8.
Step 5 - Possible restoration of the normal, alias primeval, conditions
or possible compensatory conditions
It is clear that Paleolithic diet and lifestyle are optimal to prevent malocclusions and
urolithiasis, but it is also true that the return to ancestral conditions of life is not feasible.
More realistically, it is certainly useful to correct as much as possible those changes in diet
and lifestyle that to a greater extent show to increase disease frequencies.
Available data suggest the following indications:
- to increase the intake of dietary calcium, potassium and vitamin D to the levels estimated
for the Paleolithic ;
- to increase the exposure to sunlight, so as to increase the production of vitamin D;
- to increase the intake of foods and elements that reduce oxalate absorption and calcium
absorption (and therefore urinary calcium: K, PO4, fiber, Alkali Load alias fruits and
vegetables);
- to increase the intake of plain water;
- to reduce the intake of the foods and elements that increase oxalate absorption and calcium
absorption (and therefore urinary calcium: supplemental Ca, Na, Mg, Carbohydrates, Acid
Load alias animal flesh).
Step 6 - Analysis of the results achieved and ideation
and proposal of further improvements
Afterwards, it will be indispensable to evaluate the results obtained with different types of
diet more or less suited to these principles.
Useful indications will be obtained from these results, which obviously in their application
will be influenced by economic factors, dietary customs, and individual choices.
At the same time, it is essential to continue the deepening of the study of ancestral conditions
of life to which our body is better adapted.
If these guidelines were not followed, the populations will gradually adapt to the new
conditions of life with known evolutionary mechanisms, but it is good to point out that this
choice is ethically unacceptable as it would result in countless cases of illness and death
before, over many generations, a good adaptation will be reached.
First Objection
Before applying these measures of prevention on a large scale,
observation of controlled groups in order to confirm their validity
is necessary.
But this objection would be generated by a contradiction of current Medicine.
In fact, if a new drug is proposed, we rightly expect a series of experiments, in several
stages, before its use is authorized. Meanwhile, the NON-use of the drug is considered to be
due and NOT subject to preventive experimentation.
On the contrary, in the case of a new habit of life, alias a change of the ecological niche, the
new habit is introduced and accepted WITHOUT any trial that demonstrates its safety.
Now, If a new NOT tested habit of life is suspected of causing illness, the indication to stop
this habit of life is rightful and proper.
Why, before its suspension, should we demonstrate its harmfulness and the benefits
resulting from its suspension?
Such an absurd principle has been used for decades to extend the use of smoke without that
smokers were at least warned of the deadly risks they were running. Again a new habit
(smoking) was introduced without any evidence that proved its safety and for decades it was
claimed that its harm should be proved before taking action against it.
After many
scientific tests
(while the slaughter
continued)
Any change of the ecological
niche to which a species is
adapted must be considered
potentially harmful until the
contrary is proved.
In the case of a new drug, this
principle is observed!
[Precautionary principle]
But for other modifications of
the ecological niche, no
precaution is taken.
It is presumed – irrationally
and stupidly, because of nonscientific evaluations – that a
modification must not be
considered harmful until the
experience
proves
the
contrary!
[Imprudence Principle]
The correct scientific logic would be to take steps against a change in the
ecological niche on the sole grounds of the suspicion that this change is
bad and BEFORE the sure demonstration in irreproachable scientific
terms.
Afterwards, the results in populations (or fractions of populations), which pursue - to a
greater or lesser extent - the restoration of more physiological (alias natural) conditions
must be compared both to confirm the expected results and for evaluating other possible
measures.
But one should not expect the results of test samples before applying the aforesaid
preventive actions on a large scale.
Second Objection
Malocclusions and urolithiasis should be attributed to the combination
of environmental and genetic factors.
This is a misleading way of describing the case.
Certainly, when an individual is exposed to an ecological niche to which its genes are not
adapted, in the diseases that are caused by the altered ecological niche, his genes, which are
more or less resistant to the onset of diseases, come into play.
But, we cannot and should not consider the genes that are less resistant to the diseases as
pathological: they are entirely normal genes that in new conditions, to which the species is
not adapted, have responses that are more or less effective against the onset of pathological
changes.
For example, our species is certainly not adapted to smoking.
If, in smokers, some suffer respiratory failure, others chronic bronchitis and others cancer,
it is not correct to say that those who develop these diseases have bad genes that somehow
must be corrected, or for which it is necessary to develop opportune treatments.
The logic says that we must avoid the alteration of the ecological niche and thus prevent the
development of diseases that result from it.
It should be noted that in some cases malocclusions or urolithiasis are actually due to genetic
alterations. In these cases any preventive measure is not able to prevent the diseases. But, if
we refer to data from the study of populations living under primitive conditions, the
incidence of such cases is rare. Therefore, the attribution of responsibility to genetic factors
should not be an excuse to diminish or avoid to address the most attention and efforts on
prevention.
Conclusion
Malocclusions and urolithiasis involve significant costs and causes sufferings, reduced
quality of life and even death.
Current Medicine is directed to pursue means of correction that are increasingly
sophisticated and refined.
But the best goal would certainly be to minimize new cases of malocclusions and
urolithiasis, reserving the cures to exceptional cases.
This would limit the degradation of quality of life, a lot of suffering, and - last but
something to be reckoned with - rising costs.
This is possible with the correct application of trivial principles of Evolutionary Medicine.
Conclusion
Modern doctors, largely unaware even of the
most basic principles of Evolutionism, do not
know these possibilities.
At the same time, evolutionary biologists are
unaware of the extreme importance of these
possibilities for a rational organization of a
health system that should primarily prevent
diseases.
It is therefore essential the integration of the
knowledge of Evolutionism in the active body
of current Medicine, transforming it in
Evolutionary Medicine.
Thanks
for your attention
This presentation is on my personal pages too:
www.r-site.org/ageing
(e-mail: [email protected])