Glucose from Protein & Fat
Excerpts from: The Concept of Gamma-Glucose
I believe the reader will benefit by a discussion of
the concept of the gamma-glucose theory. Ordinary glucose is a mixture of two
chemical forms called alpha-glucose and beta-glucose. Alpha-beta-glucose
mixture is derived from the cane sugar we eat and from the sugar present in
fruit; and it is an end product of the digestion of starch.
Gamma-glucose is so labile (unstable) that it has
never been isolated in the test tube and identified as such. The evidence for
its existence however, while indirect, is strong.
Many authorities in chemistry
and physiology believe it exists since it helps explain certain phenomena which
otherwise would be obscure. (Just as in nuclear physics where faith in the
existence of protons, electrons, and mesons, helps to explain many phenomena.)
Gamma-glucose is considered to be labile, highly
reactive, and readily oxidized. It is very likely that the cells of the body
prefer to oxidize gamma-glucose to the exclusion of alpha-beta-glucose.
Dr.
Shaffer, an authority on the subject, in a review of the literature on
gamma-glucose, has stated that the hypothesis appears attractive that
alpha-beta-glucose is converted under the influence of insulin into
gamma-glucose.
In this discussion, and in the present state of our knowledge,
it is sufficient to believe that alpha-beta-glucose is synthesized to glycogen
in the liver under the influence of insulin and that the glycogen is subsequently
broken down into gamma-glucose which is then liberated into the blood.
When a human lives on meat and fish exclusively, as
does the Eskimo or Arctic explorer, he is living on protein and fat. Yet
glycogen is stored in the liver in normal amounts and there is a constant
normal blood sugar level.
Where do the glycogen and glucose come from on such a
diet? They are derived from protein and fat. Fifty-eight percent of protein and 10% of fat can be converted by the
body to glycogen and ultimately to glucose.
I want to point out that the
blood sugar on such a diet may be said to exist exclusively in the gamma form. See FIG. 14 at the end of this article.
On such a diet the blood sugar is produced entirely
within the body and so may be called endogenous glucose as opposed to the
exogenous alpha-beta-glucose which is introduced from the outside in the foods
we eat.
Certainly it would appear plausible to regard the sugar derived from
meat and fish (protein and fat) as being different chemically from the sugar derived
from cane sugar, fruits, and starch.
From my studies I have been forced to
conclude that alpha-beta-g1ucose is so foreign to the
cells of the body as to be harmful to the body's economy.
There is ample evidence for this statement from
observations made by two of this country's leading researchers in metabolism,
Benedict and Carpenter.
These workers determined the minimum (basal) oxygen
requirements of normal human subjects and then measured the oxygen consumption
of these subjects after various test meals of sugar, starch, protein, and fats,
alone and in combination.
After a protein meal they always observed a marked
rise in oxygen absorption (consumption), a phenomenon called "the specific
dynamic action" of protein and which is regarded as highly beneficial to the
body.
After a fat meal there was a slight rise in oxygen absorption or none at
all. After sugar and starch they found a slight initial rise followed by a fall
in oxygen absorption in some experiments, and in other experiments they observed
a consistent fall in oxygen absorption, with no initial rise. Benedict and
Carpenter were unable to explain this fall in oxygen absorption after sugar and
starch.
They were much surprised to discover that the ingestion of sugar and
starch actually could cause a depression of total bodily oxygen absorption
below basal requirements.
Here are some of the actual experimental results
reported by Benedict and Carpenter. They fed one subject 400 grams of bananas
(413 calories) and observed an increase in oxygen absorption of 5.5 grams
during the first hour, and a fall in oxygen absorption below basal requirement
during the second, third, and fourth hours.
Bananas contain chiefly sugar and
starch. In the same subject, after 217 grams of beefsteak, (451 calories) which
consists of protein and fat, there was an increase in oxygen absorption during
each of four hours, with a total increase of 17.5 grams of oxygen against a net
increase of only 1.5 grams of oxygen after the bananas.
With larger meals the results were even more striking.
For example, after 1382 calories of a sugar mixture, there was a fall in oxygen
absorption of 11 grams over an eight hour period with no initial increase; in
other words the subject would have consumed 11 grams more oxygen if he had fasted
for the eight hours.
On the other hand, after 1305 calories of beefsteak there
was an increase in oxygen absorption of 40 grams during an eight-hour period.
Now, how does the ingestion of sugar and starch
depress oxygen absorption? There are two ways by which this can be brought
about: first, by causing low blood sugar, and second, by depressing the liver
output of gamma-glucose.
As has, been previously explained, sugar and starch
may cause low blood sugar about an hour after eating, and this period of low
blood sugar may last from one to three hours.
During the period of low blood
sugar there will be a reduced delivery of glucose to all the cells of the body
with a resultant reduced oxidation of glucose; as a result, less oxygen will be
absorbed by the body since cells utilize oxygen in proportion as they utilize
glucose.
Also, during the period of reduced glucose-oxygen consumption, less
heat will be generated and so the body temperature may fall. This reduced heat
production during low blood sugar readily explains the presence of subnormal
body temperature in certain individuals in the morning before breakfast, and
even after meals. Such individuals tolerate cold weather very poorly.
The second mechanism whereby sugar and starch may
cause a depressed oxygen consumption involves the
concept of gamma-glucose.
During fasting, the blood sugar is derived entirely
from the breakdown of liver glycogen and may be regarded as existing in the
readily oxidizable gamma form.
Now Dr. Soskin and his co-workers have found that when ordinary
alpha-beta-glucose is injected into the blood the greater the amount of
alpha-beta-glucose injected the greater the depressant effect on the liver
output.
This reduced output by the liver occurs because there is no apparent
need for the liver to pour out endogenous glucose as long as exogenous
alpha-beta-glucose is being introduced from the outside.
The injection of
exogenous glucose raises the blood sugar level and, to prevent too great a
rise, the liver responds by lowering its output. The oxygen absorption of the
body may fall, however, in spite of the rise in blood sugar level which
followed the injection of glucose, because of the reduced output from the liver
of the more readily oxidizable form which I believe
to be the gamma form.
The influx of alpha-beta-glucose into the blood drives
the gamma-glucose out of the circulation, just as bad money drives good money
out of circulation.
The oxygen absorption of the body falls in proportion as
the output of gamma-glucose falls. This concept will explain why Benedict and
Carpenter observed a moderate fall after small sugar meals and a greater fall
after larger sugar meals.
After a pure protein and fat meal (beefsteak) there
is no introduction of alpha-beta-glucose and hence there will be no depressant
effect on the liver output of gamma-glucose and there will be no fall in oxygen
absorption.
The marked increase in oxygen absorption after beefsteak may be
readily explained by the oxidation of the products of digestion resulting from
the digestion of the protein and fat.
Summarizing, the ingestion of sugar and starch may
depress oxygen absorption by causing low blood sugar and/or depressing the
output of gamma-glucose from the liver.
In some instances only one of these
mechanisms may be operating, and in other instances both mechanisms may be
operating.
In the latter, the fall in oxygen absorption will be greater than in
the former, and the fall in oxygen absorption may be so great and so prolonged
that susceptibility to infection will occur.
I wish to impress the reader with this concept of
gamma-glucose. Gamma-glucose is to be regarded as the "natural sugar,"
preferred by the cells of the body for energy purposes because it is more
readily oxidized with greater release of energy.
Alpha-beta-glucose is to be
regarded as a "foreign sugar," and, in a sense, artificial. Alpha-beta-glucose
may be oxidized directly but not as efficiently or as rapidly as gamma-glucose.
The reader should remember that the ingestion of sugar and starch with resultant
liberation of alpha-beta-glucose after digestion exerts a depressant effect on
the liver output of the preferred gamma-glucose.
Knowledge in medicine and physiology is in a constant
state of flux. New discoveries open new doors and confirm or alter previous
concepts.
In the light of our present knowledge, the concept of gamma-glucose
presented here is fundamentally sound and warranted by supporting data, and it
explains certain phenomena that would otherwise be baffling.
Regardless of
whether or not the above explanation is the correct one, the fact remains that
the ingestion of sugar and starch may readily cause a fall in total bodily
oxygen absorption through adverse effects on the blood sugar regulatory
mechanism, and it is this state of oxygen lack that is responsible for
susceptibility to infection.
Fig. a. In the fasting state the blood glucose (or blood
sugar) is derived from the breakdown of liver glycogen and may be said to exist
in the endogenous gamma-glucose form.
Fig. b. Following the ingestion of a moderate amount of
exogenous alpha-beta-glucose the blood sugar level will rise, and the blood
glucose value will now be the sum of the gamma-glucose plus the
alpha-beta-glucose.
However, the exogenous alpha-beta-glucose inhibits the
output of endogenous gammaglucose from the liver; and
the concentration of the gamma-glucose will fall as shown by the heavy line in
the figure.
Thus there may be a fall in total body oxygen absorption because of
the fall in gamma-glucose concentration and in spite of the rise in blood
glucose level.
Fig. c. Following the ingestion of a larger amount of
exogenous alpha-beta-glucose the blood glucose level rises to a high value and
the liver output of endogenous gamm2.glucose is proportionately depressed.
Under such circumstances an individual may experience hypoglycemic
symptoms even though the blood sugar actually rises. The gammi-glucose
output may be subnormal for 1 to 3 hours. After such a meal
there may be a fall in total body oxygen absorption.
Fig. d. Following the ingestion of proteins and fat the blood
glucose level rises moderately. Since no sugar or starch is ingested no
exogenous alpha-beta-glucose is available to inhibit the output of endogenous
(within) gamma-glucose from the liver.
The blood sugar will thus consist of the
gamma-glucose form exclusively. The rise in blood sugar after protein and fat
is due to the rapid conversion of the digested protein and fat to
gamma-glucose.
A meal consisting of protein, fat, and carbohydrate foods
containing no sugar or starch will also cause a moderate rise in blood sugar
and with no inhibition of liver output of gamma-glucose. After such a meal
there will be a rise in total body oxygen absorption.
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