Experiments That Changed Nutritional Thinking - TUUM EST

1030S
SUPPLEMENT
Two years later, McCollum and his graduate student Cornelia
Kennedy suggested the provisional use of alphabetical terms
for this lipin and other essential ‘‘organic complex(s),’’ using
a prefix designating characteristic solubility. Thus for this essential
factor(s) they proposed the term ‘‘fat-soluble A’’
(McCollum and Kennedy 1916). Soon this gave way to the
term ‘‘vitamin A.’’
McCollum and Davis also focused on discovering the nature
of the nutritional deficiencies of the cereal grains. Particular
attention was given to the nature of the dietary deficiencies
of rice. In their article were 42 growth charts (McCollum and
Davis 1915). Each chart portrayed the growth for each rat in
an experimental lot, the composition of the ration used, the
kind of test substance (accessory) added, if any, etc. Some of
the results are summarized in Table 1. In their introduction
they stated in part:
‘‘In the present communication we present experimental data
showing the specific properties of polished and of unpolished
rice as a food, and show the supplementary relationship between
these and certain purified and naturally occurring foodstuffs
. . . . These studies, in addition to extending our knowledge
concerning the dietary position of rice, have contributed
to our understanding of the factors involved in normal nutrition,
especially as regards the unknown accessory constituents
of the diet which have received so much attention in recent
years in connection with the ‘deficiency diseases’, scurvy and
beri-beri.’’
FIGURE 1 Prepared from McCollum’s growth charts. This male A substantial proportion of the research was on ‘‘the supplerat
received 3% cottonseed oil in its diet for the 7 wk of period 1 mentary relationship between certain extracts of naturally ocand
then received 3% olive oil that had been shaken with soaps from
curring foodstuffs and polished rice’’ in which most of the
saponified butter fat. The dotted line represents the normal growth rate
of these rats (from McCollum and Davis 1914, chart 2, rat B).
extractants employed were water, ethanol and acetone
(McCollum and Davis 1915).
This was in regard to answering the question of the presence
of ‘‘water-soluble accessory’’ in polished and unpolished rice.
sive biological analysis of foods. In this paper they began by
Water extract of wheat embryo was far superior to an acetone
stating that:
extract in supplementing a diet based on polished rice. McCol-
‘‘During the past year we have been engaged in a study of the
influence of the composition and quantity of the inorganic lum and Davis (1915) concluded that ‘‘such knowledge, when
content of the ration on the growth of the rat. In this work available for a wide variety of foodstuffs must, we believe, be
we have employed rations compounded of pure casein, carbowill
promote health.’’ Thus this study contributed to the illu-
of great value in the formulation of human dietaries which
hydrates, and salt mixtures made up of pure reagents, and the
same rations in which a part of the carbohydrate was replaced mination of all their studies on cereal grains. While their work
by lard, with a considerable degree of success. . . .’’
In their commentary on these germinal experiences with rats
fed such rations they wrote:
TABLE 1
‘‘The fact that a rat of 40 to 50 grams in weight can grow
normally during three months or more on such rations, then
Growth of young rats fed polished rice with
cease to grow but maintain its weight and a well nourished
different supplements1
appearance for weeks and then resume growth on a ration
containing certain naturally occurring food-stuffs would lead
Lot (no. of male and female rats)
one to the belief that on these mixtures of purified food substances
the animals run out of some organic complex which is 308 316 317 383 395
indispensable for further growth but without which mainte- (5 M, 1 F) (6 M) (6 M, 1 F) (3 M, 2 F) (4 F)
nance in a fairly good nutritive state is possible.’’ (See Fig. 1.)
In this article they had shown that butter fat and eggs Approx. initial
contain the ‘‘lipins’’ and that none exists in lard or olive oil.
weight g 100 40 60 60 40
Also, they showed that the organic complex was extractable Diet
with ether. In 1914 they reported that the new fat-soluble Polished rice 96 91 91 — 82
factor was transferred to olive oil by the following procedure: Unpolished rice — — — 88 —
‘‘Butter fat was saponified with potassium hydroxide in alcohol.
Rice polishings — — — — 10
The resulting soap was dissolved in water and olive oil was
Salt mix 4 4 4 2 3
thoroughly emulsified in the soap solution. The olive oil was
Egg albumen — 5 — — —
of the same sample which had been tested on rats and found
Casein — — — 5 —
to be of no value in protecting them against decline on the
Butter fat — — 5 5 5
basal diet. The emulsion was then broken with ether, and the Approx. weight
olive oil was recovered in that solvent. After evaporating the gain in 8 wk, g 0 or less 0–15 loss 65 50
ether, the olive oil was found by a feeding test to have acquired
the nutritive quality of the butter fat.’’ (McCollum and Davis 1 Based on data in five different growth charts selected from 42
1914)
published by McCollum and Davis (1915).
/ 4p09$$0062 04-07-97 14:02:12 nutras LP: J Nut May Suppl
Downloaded from jn.nutrition.org by on June 3, 2010