Chapter 5-2 of Healing
Foods by Walter Last
METABOLIC PATHWAYS
Biochemistry and nutrition are commonly taught as if the basic metabolic
pathways for energy production are used in the same way by all people, except
perhaps for some uncommon hormone and enzyme deficiencies. This, however, is an
oversimplification that leaves the health practitioner as well as the patient
without clear guidance as to how to use nutrition to overcome disease and
maintain health.
A more relevant study of our energy metabolism - the way in which our
cells produce energy from food - provides some fascinating insights into the
reasons why certain diets and nutrients are beneficial or harmful for various
diseases and for different metabolic types. While part of this study may look
rather technical and difficult to understand, it is well worth making the
effort because here we have the basis of all the disease-producing and healing
effects of nutrition. However, if this part is too difficult, then simply skip
it, or come back to it later when you want to understand a specific nutritional
problem.
GLYCOLYSIS AND CITRIC ACID CYCLE
The main energy-generating mechanism in our cells is the Krebs cycle or
citric acid cycle. This is a series of enzymatic steps through which a
two-carbon molecule (acetyl or acetate) is oxidized to carbon dioxide and
water. All three main food components - glucose, amino acids and fatty acids -
can be utilized in this way.
Glucose is normally the most important fuel molecule. Through several
reactions along the glycolytic pathway it is split in half to form pyruvic
acid. Niacinamide and vitamin B1, as co-enzymes, are the necessary vitamins at
this stage; magnesium is required in addition. Glycolysis proceeds
anaerobically, that is without the need for oxygen. See Figure 5-2 for a
diagram of our cellular energy metabolism.
The next step may be in three directions and it is here that most intracellular
energy problems develop. Pyruvic acid can either combine with carbon dioxide
and become oxaloacetic acid, or it may lose carbon dioxide and form acetyl
coenzyme A.
Combining with carbon dioxide requires a high amount of energy as well
as biotin, nicotinamide and manganese. The step in the other direction needs
oxygen and magnesium, as well as the vitamins B1, niacinamide and pantothenic
acid.
If the metabolism is in good condition, then both reactions take place
in such proportions that there are always equal amounts of oxaloacetic acid and
acetyl coenzyme A available. Both molecules will then combine to form citric
acid as the first step in the citric acid cycle. During several more steps in
this cycle, together with reactions that follow up the cycle, the acetyl
component is completely oxidized into two molecules of carbon dioxide and
water, while the oxaloacetate is re-formed, ready for a fresh turn of the cycle.
However, in practice usually a deficit of oxaloacetic acid will develop
because this is a very useful molecule that is required for many other
reactions, for instance to form amino acids or nucleic acids. The body covers
this deficit by converting an appropriate amount of pyruvic acid into
oxaloacetic acid. Important for the operation of this cycle are the vitamins
B1, B2 and niacinamide, in addition to magnesium and oxygen.
In this way, someone of the S-type ('desert Arab') can obtain all his or
her energy by burning carbohydrates. The P-type ('American Indian'), on the
other hand, will create very little of his or her energy in this way. He
produces energy mainly by forming acetyl coenzyme A directly from fats
(requiring vitamin B2, niacinamide and biotin) and from amino acids (requiring
vitamin B6). Most of the rather small intake of carbohydrates will be converted
to oxaloacetate.
The balanced type is able to use both main pathways efficiently and best
gains energy from a mixture of carbohydrates, proteins and fats. The third
path, the conversion of pyruvic acid into lactic acid, is an emergency measure
that may be used by all metabolic types. This is an anaerobic step and in most
instances is triggered by a shortfall of oxygenating enzymes, either because of
strenuous muscle activity or resulting from an allergic reaction. In fast
oxidizers the build-up of lactic acid may also be caused by an accumulation of
metabolic acids (for example, citric acid, malic acid) in the cells. Lactic
acid is partly neutralized and expelled with the urine and partly reconverted
in the liver to pyruvic acid in the presence of sufficient nicotinamide.
Fig. 5-2: CELLULAR ENERGY METABOLISM
The P-type and the balanced type tend to become fast oxidizers and
hypoglycemics on a diet high in sugars and low in proteins and fat. Most of the
dietary protein is used as a building block and little is available for energy
production.
The ability to convert pyruvic acid into acetyl coenzyme A is poorly
developed in these individuals. Therefore, oxaloacetic acid is produced in
excess, while lack of acetyl coenzyme A prevents the citric acid cycle from
fully operating. The blockage of the citric acid cycle leads to a lack of
energy and overacidity from accumulating metabolic acids and lactic acid.
Using more proteins and fats (best is olive oil) is the solution, as
fats are the most efficient source of acetyl coenzyme A. However, this will be
problematic if there is fat-malabsorption. Polyunsaturated oils, on the other
hand, require additional steps and are not so well suited for energy
production. In addition, linoleic acid may contribute to the frequent
over-sensitivity of fast oxidizers by forming certain prostaglandins that
increase inflammatory activity.
In the negative S-type we have the opposite problem where the diet is
high in meat and fat. Initially, this provides useful additional fuel, and in
combination with a raised epinephrine level makes the whole personality highly
energetic. However, there is an inverse relationship between the epinephrine
level and the effectiveness of insulin. When the epinephrine level is high in
response to this diet, the effectiveness of insulin is reduced.
DIABETES
Insulin regulates the speed with which glucose enters the cells. With a
low insulin level, cells may be starved of glucose. Then not sufficient
oxaloacetic acid is formed to combine with an abundance of acetyl coenzyme A,
which is produced internally or by a high-fat diet. In those who are strongly
SNS-dominant, this can lead to the development of diabetes. Glucose builds up
in the bloodstream and is spilled in the urine.
Figure 5-2 shows the nutritional solution to this problem. We must
provide more oxaloacetic acid. As a first step we reduce all stimulating
influences, be they from the environment or from red meat, alcohol, coffee,
tea, tobacco or drugs. This will help reduce the epinephrine and increase the
effectiveness of insulin. Then we supply an abundance of zinc, which is needed
to manufacture insulin, and chromium, which is part of the glucose tolerance
factor that helps insulin to channel glucose through the cell wall.
Oxaloacetic acid is an unstable compound that cannot be purchased.
Instead we can supply malic acid (the acid present in tart apples), which is
easily converted into oxaloacetic acid. We can supply also citric acid from
acid citrus fruits. This, too, can be converted into oxaloacetic acid through
the citric acid cycle and provides valuable energy at the same time.
Another food group that readily converts into oxaloacetic acid is the
proteins. Most amino acids can either be transformed via pyruvic acid or
directly enter the citric acid cycle. Most easily converted is aspartic acid.
Only few amino acids are ketogenic and yield acetyl coenzyme A, these are
leucine and isoleucine, lysine, phenylalanine, tryptophan and tyrosine. An
excellent energy protein for diabetics, with almost 90 per cent useful amino
acids, is gelatin.
Furthermore, fructose from fruits can enter muscle cells without insulin
to form pyruvic acid. However, it must enter the bloodstream slowly (raw food,
small meals), otherwise fatty acids, cholesterol and cataract-forming sugar
alcohols may be produced. However, type 2 diabetics have to be careful not to
mix fructose with glucose as pointed out in Step 35 on the disaccharide effect.
Sometimes glucose cannot be used and builds up in the bloodstream
because the conversion of pyruvic acid into oxaloacetic acid is blocked or too
slow. This conversion requires manganese, biotin and nicotinamide. These and
also other vitamins and minerals required for the energy metabolism should be
supplied in generous amounts.
The large build-up of acetyl coenzyme A is reduced in the liver by conversion
into saturated fatty acids and cholesterol, which both contribute to the
development of atherosclerosis. In uncontrolled diabetes a surplus of fat leads
to the production of ketones and keto-acids from acetyl coenzyme A. Ketones,
such as acetone, can to some degree be used by the muscles to form oxaloacetic
acid via pyruvic acid and thus keep the citric acid cycle going. However, this
conversion is slow and a large amount of the keto-acid acetoacetic acid
accumulates and makes uncontrolled diabetics extremely overacid. The liver can
metabolize glucose without the help of insulin, and high levels of glucose
flooding the liver can cause a large build-up of lactic acid. Thus an intake of
sweet food contributes to general overacidity.
Intestinal sanitation, avoidance of sucrose and allergy testing or a
low-allergy diet are the main features in normalizing insulin production in
insulin-dependent diabetes; a proper nutritional program is a second line of
defense and can give good results even in resistant cases such as tumor of the
pancreas.
ABNORMAL FAT METABOLISM
The metabolic problems of slow oxidizers are similar to those described
for diabetics. However, the glucose deficiency inside the cells is far less
severe and, therefore, we do not have the overacidity resulting from an
overproduction of keto-acids. Instead, the surplus of acetyl coenzyme A is
mainly converted into saturated fatty acids and cholesterol, causing
atherosclerosis, cardiovascular disease, fatty degeneration of the liver and
overweight.
In the slow oxidizers overweight is mainly a result of eating too much
fat, while in the fast oxidizer overweight results mainly from eating sweet
food and wheat. In both cases the thyroid gland tends to be underactive.
The answer to these problems is to speed up glycolysis and produce more
oxaloacetic acid. This can be done by supplying plenty of fruit acids as well
as all the vitamins and minerals required for the sugar metabolism. Minimizing
fats and sugar will stop the oversupply of acetyl coenzyme A while epinephrine
levels will fall and insulin activity rise in the absence of meat and stress.
This is the key to cleaning atherosclerotic arteries.
SUB-OXIDIZERS AND CANCER
The sub-oxidizer has an inefficient metabolism and, in a way, combines
the problems of the fast and the slow oxidizer. Many sub-oxidizers have cancer
or pre-cancerous conditions. In cancer the metabolism of all nutrients is
greatly impaired. The main energy production of cancer cells is similar to that
present in uncontrolled hypoglycemics: both produce mainly lactic acid instead
of energy. While this makes the tumor itself overacid, the rest of the body may
be too alkaline due to a very sluggish metabolism.
Figure 5-2 reveals how we can starve a tumor: we must reduce all
nutrients except fruit acids to the bare minimum. In this way the tumor is
completely deprived of energy while normal body cells can still derive energy
from metabolizing acids together with fatty acids from the fat deposits of the
body.
The time-tested method used in
natural medicine for those with sufficient fat reserves is a fast, lasting
several weeks, on fruits only, mainly tart varieties. The grape cure has become
famous; also tart apples and acid citrus fruits may be used. During this time
it is essential to clean the bowels daily (Epsom salts, colonics), otherwise
the poisons generated by a large, disintegrating tumor can cause great distress
and even death. At other times, use plenty of red beets, raw, juiced or cooked.
The red beet pigments greatly increase the oxygenating ability of the cells and
normalize the metabolism.
Chapter 5: METABOLISM AND
METABOLIC TYPES