NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
47
The last point to which we wish to refer is the salt elimination of the urine
in the form of chlorides.
The actual amount of salt added to the food of these men was up to, in
most instances, 28 grammes daily ; this was in addition to the salt already
present in the composition of the different food materials. From a glance at
Table XIII it is apparent that large quantities of chlorides were eliminated
in the urine. On the average, for the daily analyses shown, the excretion
of chlorides comes to 32.30 grammes. We have already discussed at some
length the evidence for an increased physiological demand for sodium chloride
when the diet is largely vegetable, and we have shown that excessive
quantities of salt are not generally made use of by the Bengali. The reason of
this is that rice forms the great bulk of the food of the Bengali and rice contains
comparatively little potassium salts ; so that, accepting Bunge's explanation
that the increased demand for salt with a vegetable diet depends on the effects
of the contained potassium salts causing an increased elimination of sodium
and chlorine in the urine, there is no urgent reason with diets of the above
type for a large addition of salt.
Physiologically the presence of from 4 to 6 grammes of salt in the daily
diet is sufficient protection against a loss of chlorine from the blood and tissues.
With a purely vegetable diet, as in the case of our figures for students, etc., we
found the average amount excreted daily was under 10 grammes. With regard
to these four prisoners the excretion was more than three times as great as in
other Bengalis, and, as will be evident, it corresponded very closely with
the intake.
What is the effect of this excessive ingestion of salt? Straub states when
the salt intake reaches 0.6 to 1.1 gramme per kilo of body-weight diuresis and
augmented nitrogenous metabolism sets in. In the prisoners under observation
Straub's lower limit was exceeded, and, as will be apparent from the column of
Table XIII giving the quantity of urine excreted, diuresis was a marked feature
in every instance where the salt intake was high.
This is in accordance with what would be expected and with common
experience. Salt taken in excess must either be eliminated or retained within
die system ; whether eliminated or retained water must be imbibed in sufficient
quantity to form an isotonic solution.
If the kidneys are normal this excess of salt and water is quickly got rid
of in the urine ; but, as the kidneys are only able to excrete a dilute saline
solution, large quantities of water are necessary in order to eliminate the excess of
salt—hence the thirst and diuresis.
In an ordinary healthy individual with a normal salt intake and on whom
salt equilibrium is established, if the ingestion of salt be greatly increased
48
there will be at once a large increase in the amount of salt eliminated in the
urine ; but the output will not be quite equal to the increased intake, so that
some has been retained. With this retention there must be also a retention of
fluids to keep the salt in solution ; in this way there will be an increase in the
body-weight in proportion to the degree of salt retention. Later as the system
becomes accustomed to the larger salt intake it attains, as it were, a higher level
of salt metabolism, all excess of salt above this level being got rid of so that
salt equilibrium again becomes established.
We may conclude that there is no justification for the employment of such
excessive amounts of salt in the diets of prisoners. Its effects are to increase
the work thrown on the kidneys, to increase the salt concentration of the blood
and tissues rendering the latter more or less water-logged and to cause thirst and
diuresis. In addition there will be a fictitious advance in body-weight due to the
retention of fluids by the tissues.
V.—EVIDENCE OF THE EFFECTS OF A LOW PROTEID INTAKE ON THE
PHYSICAL DEVELOPMENT OF BENGAL STUDENTS.
We were fortunate enough to secure the carefully tabulated records for a
large number of years of the age, weight, chest-girth and height of the Bengali
students attending one of the colleges. The measurements and weights were
taken for each year while the particular student was a member of the institution ;
this was usually four years. We have thus a record showing the age, weight,
chest-girth and height, for each of the four years they remained students, of
some 568 persons.
We were also able to obtain from the Medical Officer of the College an
authentic statement of the diet scale sanctioned for these Bengali students.
The value of the diet is shown in detail in Table XV.
Table XV.
Proximate Principles
S o o j i . S u g a r .
G h e e .
B a l a m R i c e .
D h a l l .
M u s t a r d O i l .
S a l t .
V e g e t a b l e s . P o t a t o e s .
G o o r T r e a c l e .
F i s h .
M u t t o n .
Proteid . . . . . 4.89 . . .
... 28.98 18.07 . . . ...
1.79 4.08 ... 2.57 6.73
Carbohydrate . . . 28.55 42.45 . . . 363.91 48.66 ... ...
4.53 46.64 14.19
. . .
. . .
Fat . . . . .
. 7 6 ... 28.27 .65 1.70 37.81 ...
.29
. 3 6 ...
. 4 1 1.30
Salt . . . . . ... ... ...
. .
...
. . .
14.19...
. . .
. . . . . .
. . .
TOTAL VALUE.
Proteids = 67.11 grammes.
Carbohydrate = 548.73
„
Fat = 71.55
„
Salt = 14.19
„
49
The diet is very much more varied and appetising than is sanctioned for
prisoners. The gross amounts of the different constituents are less in quantity—
except as regards fat—but, on the other hand, there is not such a close
approach to a cereal diet as in the Jail types, about 13 per cent. of the proteid
element being obtained from meat.
With regard to the carbohydrate and fat in the diet there is nothing
of much interest. It will be readily admitted that these elements are quite
adequate to meet the wants of the body in energy and heat-production ; in fact,
when we consider the climate of Bengal, the question would arise whether
the fat was not too abundant for the heat-production necessary in tropical
countries.
The gross proteid intake of this diet works out to be 67.11 grammes
per day, or an amount very little more than half Voit's standard. We have
shown, however, that the waste of proteid is very large with a diet consisting.
largely of dhall and rice ; in the prisoners we found this loss accounted
for more than 25 per cent. of the total proteid of the diet. Further,
with regard to the remaining proteid, if we accept an absorption of the usual
percentage—90 per cent.—we shall be able to calculate the real value of
the intake.
The absorbable proteid from the vegetable part of the diet works out at
42.45 grammes and from the animal materials 8.37 grammes. So that the real
proteid intake of the diet would appear to be 50.82 grammes and not 67.11
grammes.
This amount, 50.82 grammes, is actually less than half of the 105 grammes
of assimilable proteid of Voit's standard diet, and approaches very closely the
quantity Chittenden considers amply sufficient.
The average weight of these students was 54 kilos ; it would therefore follow
that a diet containing 50.82 absorbable proteid affords the metabolism of
0.941 grm. of proteid or expressed in terms of nitrogen the metabolism
of 0.148 grm. of nitrogen, per kilo. of body-weight. The quantity of
nitrogen per kilo. of body-weight metabolised by Chittenden's three classes
was 0.13 grm. per day ; these Bengali students had therefore a slightly
superior proteid metabolism. On the other hand, the metabolism of the
four prisoners examined was on a much higher scale ; as will be seen
above it rose to an average of 0.185 grm. of nitrogen per kilo. of body-
weight, while the investigations on students and servants of the Medical
College showed an average metabolism of 0.116 grm. per kilo. of body-
weight. In order to make these varying amounts of nitrogenous meta-
bolism for the different classes examined more easily understood we collect
them in tabular form.
H
50
Table XVI.
Place of observations.
Num-
ber.
Average
weight
kilos.
Daily proteid
metabolism (excluding
nitrogen of fæces).
Nitrogen per kilo
of body-weight
grm.
Duration.
A—America,—Chittenden—
I. Scientific workers .
.
5 63.9
47
0.12
6-9 months.
II. Medical corps
.
. 13 61.5
49
0 . 1 3
6 „
III. Athletes
. .
.
8 70.0
55
0.13
5 „
B—Medical College, Calcutta—
I. Students and Servants of
Medical College .
. 44 52
37.50
0 . 1 1 6
Life.
II. Students of another College 568 54
50.82
0.148
Four years.
I I I . Pr i soner s
.
.
4 57
66.81
0 . 1 8 5
Variable.
From the evidence of the physical development and condition of the blood
in our first series of observations— on students and servants—we were led
to the conclusion that, while the proteid intake was adequate to maintain the
system in a condition of nitrogenous equilibrium it was probably insufficient
to allow of the attainment of a physique comparable with that of Europeans.
With regard to the investigations on prisoners, in all probability the metabolism
of an intake of 66.81 grammes of assimilable proteid daily is quite sufficient
to meet ordinary physiological wear and tear in adults and to provide a
surplus for growth if required.
We shall now examine the evidence regarding the sufficiency or otherwise of
the 50.82 grammes assimilable proteid in the diet of our second class of
students.
The usual age of entrance into the College was in the 17th or 18th year—a
few entered earlier—some under 16 years of age, and a very limited number were
up to twenty years old. We may therefore regard these students as being just
about the time of life when growth and development would be most active. As
they remained, in most cases, four years at the College on the above type of diet,
the statistics of the weight, chest-girth and height of each student year by year
afford a reliable criterion on which to base an opinion with regard to the amount
of physical development that took place while on the diet stated. This in its
turn will give us a trustworthy test of the adequacy or otherwise of the diet as
a whole and more particularly—the carbohydrate and fatty elements being
51
admittedly sufficient—will afford us information regarding the physiological
minimum of proteid metabolism. What were the actual results ?
In making up the following figures we have neglected the last or fourth year
completely, as a number of the weighments and measurements for that year were
missing.
The facts are as follows :—
(1) There is an increase in the body-weight on the average over the
whole series of only 2lbs. in a comparison of the weight on entrance
and weight in the third year.
(2) In a comparison of weight on entrance and weight in the third year
42.8 per cent, of the students show a diminution in body-weight ; only
15.3 per cent. gained weight continuously during the three years.
(3) In a comparison of weight on entrance and weight in the second year of
attendance 55.8 per cent. of the students show a diminution in body-
weight.
(4) The chest-girth practically remained stationary.
(5) As would be expected from the age of entrance the large majority—
over 80 per cent—of all the students showed an increase in height
ranging from 1½ in. to 2
½
in.
In the face of results such as these we can only conclude that the meta-
bolism of 0.148 grm. nitrogen per kilo. of body-weight is not sufficient to meet
the nitrogenous needs of the growing Bengali, and in from 30 to 40 per cent. of
the 568 examined was insufficient to prevent the loss of formed tissue proteid
as the diminution in body-weight would appear to mean. These results bear out
in a very marked manner the conclusions we arrived at from a study of the meta-
bolism of the students and servants of the Medical College.
On referring to table XVI it will be seen that Chittenden was able to maintain
the individuals of his three different classes in health and vigour with no loss of
tissue proteids on a daily proteid metabolism—0.12 and 0.13 grm. of nitrogen
per kilo.—actually lower than even that of these students. The explanation of
this discrepancy would appear to depend probably on differences in the chemical
composition of the proteid molecule in the two cases. More, perhaps, of the
proteid products of digestion—although absorbed—being eliminated at once by
the kidneys, and never having been of any real service to the body, in the case of
diets of the type common in Bengal than is true for the food material made use
of in his experiments. Another factor which we believe to have a marked
influence on the nitrogenous requirements of the body is growth of the higher
proteid-containing tissues. It is evident that when proteid is being stored up in
the body in the form of "flesh"—as is the case during infancy and childhood—
more will be required in the diet than is necessary when it is only a matter of
replacing the loss due to physiological wear and tear. This would go far to
H 2
52
explain the discrepancy above noted as the larger proportion of those of the
students who lost weight were below 18 years of age and were therefore in need
of a higher protein intake than provided in the diet. The individuals on whom
Chittenden experimented were, on the other hand, all fully matured adults with
their total mass of proteid-containing tissues already formed, so that retention on
that account was unnecessary ; nitrogenous equilibrium could therefore be
established on a comparatively lower proteid intake.
It is quite possible that in the construction of tissue proteid certain groups
of molecules are needed and, in order to obtain these, there must seemingly be a
wasteful use of proteid food, hence the demand for a large nitrogenous intake
during early life. Further, in connection with this subject, facts are beginning to
accumulate pointing to the specific nature of the proteid counting for something
in nutrition. Chittenden states with regard to the experiments on feeding of
dogs : "It is somewhat impressive to note how well dogs thrive on a relatively
large amount of vegetable food, provided there is a modicum of animal food
added thereto. In other words, these high proteid-consumers are apparently
quite able to utilise the vegetable foods, but there is something lacking in such
a diet which the body has need of." The grouping of the atoms in the proteid
molecule is different when the proteid comes from the animal or from the
vegetable kingdom. They yield different decomposition-products or the same
products in different proportions so that in absorption and assimilation of the
proteid food-stuffs the body has to deal with the various chemical elements.
There is thus a distinct possibility, even a probability, that in the vegetable diet
of the Bengali certain cleavage products are lacking or only formed in very
small proportion, the result of which is that physical development is retarded
and, in most instances, the muscular tissues are exceedingly meagre and thin.
To quote Chittenden(1) again : "If we suppose that in the formation of
true tissue proteid or the living protoplasm of the cell, certain of these end-
products of proteid decomposition are absolutely indispensable, we can easily
picture to ourselves a dearth of such building stones in the long continued use
of a diet which lacks that particular proteid from which the necessary building
stones can be split off in adequate numbers." The conception in this quota-
tion may be applied equally truly to the replacement of old worn-out stones and
to the ordinary processes of endogenous or tissue metabolism as to the building
up of new tissue proteid.
As an example of a still more inferior type of diet we produce the value in
proximate principles of the food-stuffs laid down for students of another college
in Bengal. From enquiries we believe the students provide themselves with
extra materials—finding the scale sanctioned insufficient.
(1) Chittenden.—The Nutrition of Man, 1907.
53
It will be evident that a diet of this type is absolutely inadequate in prac-
tically every detail. The amount of absorbable proteid is below what is neces-
sary to maintain nitrogenous equilibrium and the heat value of the diet is very
deficient.
Table XVII.
Proximate Prin-
ciples.
Rice.
Dhall. Pota toes.
Green
Vege-
tables.
Mustard
Oil.
Ghee.
Meat.
Fish.
Total in
grammes.
Proteid
. .
13 55
8.43
1 . 8 1
1.86
. . .
. . .
8.06
9.87
43.61
Carbohydrate . 154.88
21.56
19.04
4.83
. . .
. . .
. . .
...
200.31
Fat .
.
.
.27
.98
.14
.30
22.68
6.80
1.18
1.57
33.92
Salt .
.
.
...
. . .
...
...
...
...
. . .
...
11.34
We have now finished our observations on the metabolism of the Bengali ;
but, before proceeding to the discussion of other lines of evidence it will not be
altogether unprofitable or uninteresting to refer briefly to certain investigations
on Anglo-Indian and Eurasian students carried out under exactly similar
conditions to those on the two classes of Bengali students.
VI.—THE EVIDENCE OBTAINED FROM A STUDY OF THE METABOLISM OF
ANGLO-INDIAN AND EURASIAN STUDENTS.
Under this heading we shall discuss the knowledge derived from an analyses
of the urine of Anglo-Indian and Eurasian students who were on a known diet ;
and, in the case of certain other students of the same class a record of whose
age, height, weight and chest-girth was recorded for four consecutive years,
we shall examine the process of physical development that was observed on a
fixed and known scale of diet.
(a) Observations on the urine of Anglo-Indian and Eurasian students
living on a known diet.
The diet scale laid down for these students—shown on Table XIX—is
much more liberal than any of the diets analysed in the case of Bengalis.
Further, it will be noticed that the proteid element is derived from various
sources, well over half being animal in origin. Although the quantity of
proteid falls short of Voit's standard the results of our investigations would go
far to prove that the proteid intake was sufficient to meet all the nitrogenous
requirements of these students.
Of course it is open for anyone to say that with a larger proteid intake
even better results might have been obtained. All the evidence we have
54
hitherto been able to accumulate would certainly point to the fact that with a
diet poorer in nitrogen—particularly in the case of young growing adults—a
defective physical development must be expected. We give in tabular form
the urine analyses carried out.
Table XVIII.
No.
Quantity
in C. Cs.
Sp. Grayity
Urea in
grms.
Total
nitrogen in
grms.
Freezing-point. Chlorides
in grammes.
No. of conse-
cutive days on
which analyses
were carried
out.
1
.
.
.
1227
1015
16.21
8.55
—1.25ºC.
11.82
4
2
.
.
.
941
1019
18.91
9.32
—1.51ºC.
12.62
5
3
.
.
.
955
1018
17.87
8.37
—1 . 55ºC.
13.38
5
4
.
.
.
1320
1012
1 9 . 8 0
9.02
—1.11ºC.
8.11
5
5
.
.
.
740
1025
19.74
9.52
—2.18ºC.
13.70
5
6
.
.
.
1120
1016
19.36
9.23
—1.51ºC.
9.13
5
7
.
.
.
1760
1 0 1 1
23.14
11.33
—1.05ºC.
11.33
5
8
.
.
.
1234
1013
20.94
10.10
—1.35ºC.
10.08
5
9
.
.
.
887
1 0 1 8
18.88
9. 10
—1.66ºC.
8.50
5
Table XIX.
SHOWING THE SCALE OF DIET OF CERTAIN ANGLO-INDIAN AND
EURASIAN STUDENTS.
Proximate Prin-
ciples.
Beef or
Mutton.
Po-
tatoes. Bread.
Mixed
Vege-
tables.
Rice. Dhall. Jam.
Eggs. Butter. Ghee. Sugar. Milk.
Proteid .
. 46.53 3.12
23.40
2.32
3.62
3.29
.06
1.62
...
...
...
3.60
Carbohydrate
...
74. 32
184.32
6.04
44.4 I
8 . 1 1
2.63
...
...
...
56.72 5.21
Fats
.
. 18.88
.64
5.18
.38
.28
.26
...
1.64 12.12 12.12
...
3.25
Proteid
=
87.56 grammes.
Carbohydrate = 376.53
„
Fats
=
54.75
„
Salt
=
q. s.
From the 42 observations on the urine collected in Table XVIII we
find the average elimination of nitrogen is 9 . 39 grms. daily, or the metabolism
of 58.68 grms. of proteid from an intake up to a possible 87.56 grms. per day.
This would apparently mean a very high percentage of proteid loss in the fæces.
55
or a too liberal allowance of provisions, a large amount remaining uneaten.
From enquiries we were given to understand that the rice and dhall often remained
over but that the remaining portions are always consumed.
It must be remembered, however, that the students we are dealing with are
all between the ages of 16 to 20 years—at the period of life when growth is very
rapid—so that large quantities of nitrogen are being retained for the building
up of the proteid-containing tissues ; this amount of nitrogen will therefore not
appear in the urine at all, and any calculation of the proteid-interchange based on
the excretion of the total nitrogen would therefore be too low.
From a personal experience extending over five years we can confidently
assert that these students grow and develop very rapidly and, before their course
at College is over, they have grown into strong, healthy men. As evidence that
this is the case we have the fact that the College football, hockey, and cricket
teams can do more than hold their own against the various clubs in Calcutta.
It may be accepted that the diet sanctioned is therefore sufficient to cover all
the physiological requirements of these students.
This opinion is borne out by weighment and measurement.
The average weight on entrance—age about 16 years—on all the observa-
tions we have been able to obtain is 115 lbs., and by the end of the third year
has risen to an average of 133 lbs. or an increase in three years of over 18 lbs.
in weight. The chest measurement over the same period shows a gain of up to
an inch on the average. These figures are markedly different from what was
found true for Bengali students.
By taking the average weight of these Anglo-Indian students we can esti-
mate the proteid metabolism per kilo. of body-weight.
It must be between the
figures 58.68/57 and 87.56/ 57 The numerator of the former fraction is the amount of
proteid metabolism calculated from the total nitrogenous elimination of the
urine, the numerator of the latter is the gross proteid intake ; the denominator
in both instances is the average body-weight in kilos. As it is evident from
the above figures that rapid growth and muscular development are taking
place, so that there is a large retention of proteid, the quantity 58.68
/ 5 7 i s t o o l o w ; f u r t h e r , a s o n l y a b o u t 8 5 p e r c e n t . o f t h e p r o t e i d o f a d i e t o f
the above type is absorbable it follows that the figure 87.56/57 is too high. We
shall not be much in error, however, if we accept the latter amount, deducting
15 per cent. for non-absorbable proteid and taking into account the loss of
proteid in the uneaten portions of rice and dhall ; this would bring the average
proteid metabolism very close to 70 grammes daily, or expressed in terms of
nitrogen would mean the metabolism of 11.2 grms. of nitrogen per day. The
nitrogenous metabolism per kilo. of body-weight is therefore 11.2/57=0.196 grm.