From Annals of Dentistry,No. 6, 1947
OUR TEETH AND OUR SOILS
WM. A. ALBRECHT, A.B., B.S., M.S., PH.D.
Department of Soils, College of Agriculture, University of Missouri
The knowledge about the human body and its many functions has been
accumulating seemingly very slowly. The additions to our information have awaited
the coming of each new science and the contributions by them in their respective
fields. Dentistry as well as the medical profession has been ready and quick to accept
and use any new knowledge that might alleviate human suffering. In medicine, for
example, one can list the major successive additions almost as separate sciences
coming at the slow rate of about one per century. Anatomy was the beginning one
making its debut in the sixteenth century. The seventeenth century brought us
physiology; the eighteenthadded pathology; and the nineteenth emphasized
bacteriology, all these for our better health.
Very probably the twentieth century will be credited with the addition of the science
of nutrition as a major contribution to the better life of our people.Better nutrition is
leading us to think less about medicine ascures and less about fighting microbes with
drugs. In a more positive way it is helping us to think more about helping the body
defend itself by being well-fed and therefore healthy.
If we are to bring about good nutrition by means of good food, to build up a good
defense for the body, that defense must bestrong, not only against enemy invasions,
as it can be against tuberculosis, but also against the degenerative diseases like the
heart troubles, cancer, diabetes, etc. For such defense then of necessity, the science of
the soil and its fertility, by which alone high quality foods can be provided, may well
be an addition during the present century to our knowledge of the better functions and
better health of our bodies. It is proposed therefore in this discussion to lead you to
think about the health condition of only one part of our body, namely, our teeth as
they are related to the fertility of our soils.
SOME BASIC FACTS INVOLVED
In dealing with the subject of soil fertility and its implications for our teeth, or for
any otter part of our anatomy and our physiology, it is essential that one establish
certain facts and principles at the outset and then follow through as these seem to have
causal connections with the phenomena under consideration.
The first fact that may well be considered is the observation that under moderate
temperatures the increase in annual rainfall from zero to 60 inches, for example–as is
the range in going across the United States from near the Coast Range eastward–gives first an increased weathering of the rocks. That change represents increased soil
construction.Going east from zero rainfall means increasingly more productive soils
until one reaches about the mid-continental area. Then with still more rainfall, there
comes excessive soil development under the higher rainfall which means increased
soil destructionin terms of soil fertility considered both in quantity and in quality.
The second important fact in connection with this climatic pattern of soil
development is the observation that at the maximum of soil construction (and in the
approach to it), which is nearthe 100th meridian of longitude, there is a wide ratio of
the exchangeable calcium to the exchangeable potassium on the colloidal clay of the
soil. There is a similar ratio of these two in the chemical composition of the crops and
other vegetation grown thereon.
Then there is the third significant fact, namely that calcium is associated with the
synthesis of proteins by plants, while potassium is associated with their synthesis of
carbohydrates. The latter process, which is commonly spoken of as “photosynthesis”,
may well be considered a supra-soil performance. This classification is proper since
photosynthesis is a compounding of carbon, hydrogen and oxygen–all weather-given
elements taken from the air and water–into carbohydrates by sunshine energy. The
process of synthesizing proteins is a biosynthetic process, that is, one by the life
processes of the plant. It seems to be a case in which some of the carbohydrates serve
as the raw materials out of which the proteins are made. Thisis brought about by
combining with these carbohydrates some nitrogen, some phosphorus, and some
sulfur, all coming from the soil. At the same time, some calcium, and possibly several
other soil-borne nutrient elements are required, while more of the carbohydrates are
consumed as energy materials for this conversion process.
The fourth significant truth that bringsthe soil fertility into control of the
composition of our food, and therefore of our health, comes out of the facts (a) that in
soils under construction by the limited climaticforces, or those with a wide calcium-potassium ratio, proteinaceous and mineral-rich crops and foods as well as
carbonaceous ones are possible, and (b) thatin soils under destruction by excessive
climatic forces, or those with a narrow calcium-potassium ratio, protein production is
not so common while production mainly of carbohydrates by the crops is almost
Out of these climatic, pedologic, and physiological facts there comes the major
principle of concern to the dentists, namely, we have in the regions of higher rainfall
the excessive carbohydrates in Nature and therefore may expect them in the human
diet. Where rainfall is high enough to encourage vegetation in abundance there we
have a hindrance to sound teeth from Nature herself, because of too much
carbohydrate, or conversely, insufficient proteins and minerals, a fact–all too familiar
to those in the dental profession–hat militates against sound teeth. We need then to
realize these facts and consider them by remembering our geographic location and in
our management of the soil with human nutrition in mind.
Excess of carbohydrates is natural
In considering soil fertility as it provokes excessive carbohydrates but deficiencies
of proteins and minerals, we need only tolook at the chemical composition of the
human body in comparison with that of plants(Table 1). From these analytical data
we can see that potassium is taken into the plants in largest amounts of all the mineral
elements from the soil, while calcium and phosphorus are next in that order. In the
human body, these same elements are the major three, but calcium is first, phosphorus
second, and potassium third. Of amounts still higher than any of these in the human
body is nitrogen. This is the key element distinguishing protein synthesized as amino
acids from the elements only by plants. Plants offer us mainly carbohydrates with
only small amounts of proteins. Plant composition, considered as our food, represents
possible shortages of proteins, of calcium, of phosphorus, and of probably other
essential elements. We, like other animals, are constantly in danger of deficiencies of
proteins and minerals, especially as we are more vegetarian. By the very nature of he
creative processes that start with the soil, carbohydrates are plentiful while there are
deficiencies of minerals and proteins. Man is therefore always faced with the
shortages of minerals and proteins relative to the carbohydrates and fats. It is this
nutritional need that encourages his carnivorousness and his use of animal products
such as eggs and milk.
Excessive carbohydrates are invoked by our fertility pattern
That these shortages of minerals and proteins vary according to the pattern of soil
fertility is demonstrated very clearly by the soils of the United States. The lower
rainfalls of the western half of our country(the area of sparse population) have not
removed the calcium and the other nutrient cations from the surface soil. These lime-laden, mineral-rich areas have been the prairie soils. It is on these that the legumes as
protein-rich, mineral-providing forages flourish widely and profusely. It is these soils
that were feeding buffaloes in the early days by their grass without purchased protein
supplements. It is these soils that are giving us protein products in beef and lamb
When one looks at the eastern half of the United States (the area of dense
population) this part of our country with its higher rainfalls has soils leached so highly
that most of the calcium has gone from these to the sea. In fact, that loss of calcium
has made us classify them as “acid soils”, as though the acidity rather than the
shortage of fertility were responsible for their failure to grow protein-rich legumes.
They were originally growing only wood as forests. When cleared of these they have
been growing starchy crops. It is on these eastern soils that we fatten the cattle that are
bom and grown on the soils farther west. These eastern soils can still grow hogs
whose carcasses are mainly fat. Such soils if given fertility treatments can produce
proteins by reproducing and growing the animals themselves but usually only with
much help by attending veterinarians. Eastern United States is the area of increasing
troubles with our dairy cattle, such as what is called “brucellosis” when affecting the
cows and “undulant fever” when a disease of the human. Both of these diseases are
still baffling to the diagnostic efforts aiming to locate their fundamental cause. If the
Creator himself was making only such carbonaceous products as forests on those soils
shall we not believe that such products must represent about the limits of our
possibilities when we take over and grow crops on them without adding fertility to the
Soil exhaustion spells deficiencies of proteins and minerals but excess of
Soils naturally highly weathered are no longer well stocked with nutrient mineral
reserves in their sand and silt fractions, nor with mineral fertility adsorbed on the clay.
Such soils must of necessity give crops and foods which are mainly carbohydrates and
are therefore deficient in proteins and minerals. But quite the opposite, the less
weathered soils under low annual rainfalls are mineral-rich in the silt and sand
reserves, and on the clay. Hence they give both proteins and minerals along with the
carbohydrates in the plants grown on them.
In these facts we have the suggestion that any soil undergoing exhaustion of its
fertility, whether by Nature or by man, is bringing about a change in the chemical
composition of any plant species growing on it. This change means that the plant
species become more carbonaceous, less proteinaceous, and less mineral-rich. These
changes occur within any single plant species, too commonly believed constant in its
chemical composition regardless of the soil growing it.
Surveys and experiments demonstrate the facts
That we may well take cognizance of this as a principle, has been demonstrated by
the study of the chemical composition of the many crops and other plants as they are
native to soils that are (a) slightly, (b) moderately, and (c) highly developed under
increasing rainfall and temperature. While some thirty plant species, common on the
slightly developed soils, contained enough calcium, phosphorus and potassium in total
to make up almost five percent of their dry weight, this figure dropped to tour percent
in going to a similar number of plants native to moderately developed soils. Then it
dropped to less than two percent ingoing to plants natural to highly developed soils.
As the soils are more highly developed then, or farmed under higher rainfall and
temperature, they can provide us, through the plants on them, less and less of these
minerals essential for bone growth and less of those associated with synthesis of
proteins by the plants.
Experiments by Dr. E. R. Graham at the Missouri AgriculturalExperiment Station
have demonstrated how less calcareous soils make less of proteins and more of
carbohydrates; or that the changing calcium-potassium ratio of higher development of
the soil brings corresponding decreases in the protein and mineral contents of the
same kind of vegetation. He grew soybeans on soils with (1) a wide, (2) a medium,
and (3) a narrow ratio of the calcium to the potassium. He reproduced the conditions
of soils under increasing weathering or under increased experience with rainfall and
temperature. These three soils represented increasing encouragement for the plants to
produce carbohydrates more than to synthesize proteins.
This narrowing ratio of the calcium to the potassium resulted in an increase of
vegetative bulk by one-fourth. Such an increased tonnage would warrant agronomic
applause. But this increase in vegetative mass represented a reduction in the
concentration of protein by one-fourth, a reduction in the concentration of phosphorus
by one-half and a reduction in the concentration of calcium by two-thirds of that in
the smaller tonnage yield.
By modifying the relative amounts of calcium and potassium in the soil much as
they are modified under increasing weathering of the soil, the physiology of the plant
was shifted to the production of less protein and to the production of more
carbohydrates. Higher soil development and more rainfall and temperature, then,
bring less protein production by any crop and therefore less proteins and minerals in
our feeds and our foods.
Concentration of protein in our food crops is being lowered by soil exhaustion
As our soils are being exhausted of their fertility by cropping under the intense
economic pressure now being put on them, a single grain crop like wheat is producing
itself of less protein and of more starch as time goes on. We say “wheat is becoming
soft where once it was hard”. In our near-colonial days we produced hard wheat in the
valley of the Geneseo River of New York. That wheat basket, or breadbasket of this
country at that time, made Rochester the “Flour City”.
Today Rochester is still the “Flower City” with its many parks. But the “hard” wheat
has moved westward across the United States, while the “soft”, starchy wheat—which
we seemingly desire for our pastries—is crowding along in its wake. “Soft” wheat has
now gone so far west that even in Kansas the millers and bakers are complaining
about its low protein content and their low volume of bread output per unit of flour
used. The farmers of Kansas, however, are delighted with their high volumes of
output as bushels per acre that are possible when the plants collect only carbohydrates
instead of converting these into protein of much less bulk as plant output.
Corn, too, is doing less in its synthesis of proteins. While we have pushed up the
volume of its output as bushels per acre by hybrid vigor, we have not realized that the
concentration of protein in our corn grain was dropping from a mean figure of about
9.5 percent to only 8.5 percent during the last ten years.
Forage crops, as well as grain crops, have been going to lower concentrations in
minerals and proteins. They have been going lower in giving us what may be called
the “grow” foods but have been holding up in supplying for us what may be called the
“go” foods, namely carbohydrates. But while this is happening there is greater
deception by the crop of which only vegetative mass is of concern or is measured,
than when the harvest taken is the seed or the plant’s efforts for its own reproduction
and continuance of the species. As we harvest vegetative bulk we fail to note the low
delivery of protein which reports itself as lowered grain yield more noticeably than as
less vegetative bulk.
As we mine the soils of their fertility so that the output by one crop as bulk goes
down, we search the world and bring in some exotic crop because it can make tons or
bushels where the preceding crop failed. If this imported crop makes vegetative tons
where the others failed, it must be putting out it products with less of soil fertility in
them and therefore they must be more carbonaceous and probably of deceptive
As a consequence of the lowered protein concentration in grains and grasses under
soil fertility depletion, we have not only had the westward march of “hard” wheat, and
the clamor for more “grass” agriculture, but also a westward march of our protein in
beef and lamb. Chicago is no longer the major beef cattle market. That honor now
rests on Kansas City. Even the hog market, a trader mainly in fat products, has moved
to central United States when it once was farther cast. These movements have been
under the force of a declining soil fertility and are not merely the result of man’s
wanderlust or his nomadic nature.
Here, then, in the soil fertility is the pattern of the nutritional values of our foods
and feeds pointing out their lowered concentrations of minerals and proteins. Here is
the lowered power of growth and lowered capacity for reproduction. Life is not
passed from one fat globule to another, nor from one starch grain to another, but only
from one protein to another protein molecule. Can a dentist see good permanent teeth
being laid down in the jawbone of a foetus when the mother’s diet is deficient in
minerals and protein? Can he find sound teeth in school children when carbohydrate
bulk predominates in their diet because of its lesser cost and easier storage than that of
milk and meat? Is it any wonder that we were startled when COLLIERS told us of
“The Town Without a Toothache” located in the region of lower rainfall?
Geography of denial defects in the United Stales and the pattern of soil fertility
That Hereford, Texas, is in the part of the United States of highly fertile soils is not
so startling when the geography of dental defects on a larger scale is considered. The
recent physical examinations of the millions of men taken into the Army and the Navy
give a wealth of data in relation to the many possible factors in control of our health
and of the condition of our teeth. These data may well be correlated with the fertility
of the soil for their suggestive value in listing many of our health troubles as possible
deficiencies originating in the soil. In those data and records there is an opportunity to
relate the caries of the teeth to the soils of the United States according to their pattern
of fertility, or to their degree of development by the climatic forces.
Very recently Comdr. C. A. Schlaek and Lt. Birren of the Navy Medical Research*
Institute presented some data by regions of the United States which represented the
condition of the teeth of 69,584 men coming on active duty in the Navy in 1941-42.
These represented 93 percent of a lot from which 7 percent, had already been
eliminated for dental reasons. This screening reduced the regional differences, but
even in spite of this, those regional differences show a decidedly interesting relation
to the development of the soil.
* C. A. Schlack and J. E. Birren. Influences on Dental Defects in Navy Personnel. Science 104:269-262, 1946.
From the report of these naval officers, one is almost astounded at the poor dental
condition in this sample of our people. Itis especially serious when these naval
inductees represented the mean, youthful age of 24 years with 82 percent of them
below the age of 30 years. For the group as a whole the report reads as follows: “The
mean number of simple and compound cavities was found to be about ten per person
… and five fillings per person.” “Few teeth required extraction, despite the large
number of carious teeth, the mean number per person being about 0.2. In contrast, the
mean number of missing teeth was 4.7 at the time of the examination.”
This is a sad commentary on the dental condition of our young men when the
statistics list them for an average of 15 carious areas each, in spite of the regular
encouragement by the radio to use the tooth brush daily and to “see your dentist twice
a year.” But when the chemical composition of our teeth tells us that they consist
mainly of calcium phosphate, and when the foremost fertilizer treatments needed to
grow even carbonaceous vegetation on our soils are lime (calcium) and
superphosphate (phosphorus), there is good reason that the poor dental condition of
these naval inductees should be connected with the low fertility of these soils. When
soils need lime and phosphate to grow agricultural vegetation much more will they
need these fertilizer additions of calcium and phosphorus in order to pass these
nutrient elements on to the animals and the humans in the chain of decreasing chances
to get these soil-borne requisites for good sound teeth.
By recalculating the dental data of these naval inductees so as to make them
represent more nearly the soil areas according to increasing degrees of soil
development in going from the arid West to the humid East, the correlation is very
striking. It is highly significant that the lowest numbers of carious teeth are in the
longitudinal belt of dual-state width just west of the Mississippi River. Hereford,
Texas, is included in this belt. As one goes either westward or eastward from this belt
to other similar belts, the tooth troubles increase. This increase, however, is much
larger in going eastward, that is, to the excessively developed soils under higher
rainfall and temperatures, than it is ingoing westward to the underdeveloped soils.
Here is a clear indication that those soils with a high capacity for protein production,
because of their high mineral fertility, are the soils that have also grown better teeth.
These are the soils of the open prairies.
Quite differently, however, those soils that have a low capacity for producing
legumes, beef, and mutton and have been growing starchy grains and fattening the
livestock, have a much higher number of carious teeth per person. These are the soils
of the forested areas or the potential producers of mainly fuel foods.
The maximum number of caries was exhibited by the men from the New England
States where the cavities amounted to 13.5 accompanied by 7.8 fillings per person or
a total of 21.3 carious areas per mouth. With such numbers of defects it seems a pity
that we can’t have more than 32 adult teeth. In the Middle Atlantic States just south of
New England, the total figure was 19.6. Still farther south the corresponding value
was 13.4 of which 9.7 were cavities and 3.7 were fillings.
In this case of the soil and teeth as one goes south from New England there are three
factors that may help explain the decrease in caries. There is first, a decreasing ratio
of rainfall to evaporation and therefore less relative leaching of the soil; second, there
is less acidity to break down the mineral reserves because of the nature of the clay;
and third, in the South there is the more general use of fertilizers consisting mainly of
carriers of calcium and phosphorus.
In these regional data there are the suggestions that the curve of the condition of the
teeth is the reciprocal curve of the fertility of the soil. We may expect also, from these
relations, that the pattern of soil fertility is in control not only of the health of the
teeth, but also of health in general. This is strongly suggested by a careful study,
reported by Dr. L. M. Hepple of the University of Missouri, of the more than 80
thousand draftee rejections from more than310 thousand selectees for the Army from
Missouri alone. He points out, for example, that Kansas had lower rejection rates than
Missouri. This is another way of telling us that the health troubles increase in going
from the calcareous soils of Kansas to the lime-deficient soils of Missouri.
Equally as interesting in terms of the increase in draftee rejections as the soils are
less fertile, are his data in going across Missouri from the northwest to the southeast,
which means going from the legume and cattle area to that of cotton. His series of
figures for draftee rejections in making that traverse of the state was 208, 247, 280,
339, and 368 per thousand selectees. Even for an area so limited as Missouri, the
health condition in terms of Army standards reflects the pattern of the fertility of the
From all of the data of the inductees into the Army and the Navy there is the
suggestion that more of our so-called “diseases” may well be statistically mapped for
the United States and compared with the map of the soil fertility. If all other body
irregularities as well as those of the teeth were so viewed, it is highly probable that,
many of our diseases would be interpreted as degenerative troubles originating in
nutritional deficiencies going back to insufficient fertility of the soil. Surely the
millions of health records of the inductees into our national defense) will not be left
lying idle in Federal archives when they can be sorted out as specific diseases, plotted
as densities over the soil fertility pattern, and possibly give suggestions for combating
the failing health that rests on the great fact that degeneration of the human body goes
with the exploitation of the soil.
If the decay of teeth is linked with the declining fertility of the soil, this concept of
tooth troubles may well be a pattern to guide our thinking about other health troubles,
not as calls for drugs and medicines, but for conservation in terms of a new motive,
namely better health via better nutrition from the ground up.