Contribution to the volume Functional Biochemistry of Cell Structures,
   dedica.ted to the memory of Academicia.n N.M. Sissakian.)

Orthomolecular Nethods In Medicine

Linus Pauling

Center for the Study of Democratic Institutions,
P.O. Box 4068, Sa,nta Barbara, California 93103

   For over thirty years I have-been interested in the problem

of the molecular structure of the human body, the molecular ba,sis

of disease, and, more generally, the molecula,r.basis of life. I

shared this interest with my friend Academicia.n N.M. Sissa.kian,

and I am confident that,  if he had known a.bout them, he would ha,ve

been interested in the ideas that are expressed in the following

para.gra.phs.

A number of years ago my coworkers and I announced our dis-
                                             I

covery that a disease, sickle-cell anemia, &the result of the
gene-controlled manufacture by the pa.tient of a. kind of'hemoglobin

different in molecular structure from norma. a.dult human hemoglobin,

1

which is manufactured by most human beings.   We entitled our pa.per

Sickle-Cell Anemia,  a Molecular Disease:  I discussed this discovery

and the concept of molecular disease in a, public lecture in Moscow

in 1957, shortly after the Symposium on the Origin of Life that

had been arra.nged by Academician.A. I. Oparin.  Tne concept of

molecular disease is, of course, a. somewhat artificial one. We
might say that every activity of the human body is molecular, that

every disease is molecular, sin&e the huma.n body is composed of

molecules,  and vectors of disease,  such as viruses and ba.cteria,,

are also composed of molecules.  Moreover,  the manufacture of the


Orthomolecular Methods in Medicine

Page Two

abnormal hemoglobin, sickle-cell-anemia, hemoglobin, that is

characteristic of the disease sickle-cell anemia  is the result of

the presence in the patient of a muta.ted gene.  The gene-itself

is a. molecule, and the disea.se might be described a,s a molecular
disease because it results from the presence of an altered, mutate.d,
molecule of DNA, the gene.  In this-respect all of the diseases

resulting from gene muta.tions, the inborn errors of metabolism,
in the words of Harrod, might well be described as molecular diseases.

Presumably, however,  4& &&22&&Q% resulting from ma.croscopic
change in structure of the human body without any change in the
nature of the molecules composing it (for example, insanity following
the accidental cutting away of part of the brain) would not be

described as a molecu1a.r disease.  The discovery of, the abnormal

hemoglobin associated with sickle-cell anemia showed that some

diseases of genetic origin involve   the manufacture, under the

control of the muta.ted gene,  of a protein molecule wit,h structure
different from that of the normal protein molecule, manufactured

under the control of the normal gene.tThe hemoglobin molecule

                         A
contains four polypeptide chains,  two a.lpha, cha.ins a,nd two beta. cha.ins.
The difference in structure of sickle-cell-anemia hemoglobin  and
norma. adult human hemoglobin has been shown to be the change in a.

single amino-acid residue in the beta chain.  Almost all of the

approxima,tely 100 abnormal human hemoglobins that have been dis-
covered during the last eighteen years involve a single amino-a.cid
repla.cement in either the alpha chain or the beta chain.


Orthomolecular Methods in Medicine               Page Three

   Many of the inborn errors of metabolism involve the failure

to ma-nufa.cture an enzyme,  or involve the manufacture of a.n altered

enzyme tha.t hams much sma.ller enzyme a.ctivity tha.n the norma. one.
A great amount of information about the enzyme activity of normal
a.nd abnormal enzymes has been obtained from studies of wild-type
and mutaSted microorganisms, especially the studies of Neurospora,
initiated by G. W. Beadle and E. L. Ta.tum.  In their first pa.per
on the genetic control of biochemical reaction in Neurospora, 2

Beadle and Tatum reported their isolation of a mutant with decreased
a,bility to synthesize pyridoxine (vitamin B6).   This mutant strain

grows on the ba,sic medium that supports normal growth of the wild
type at a. rate only ten percent of that of the wild type.   Its

growth rate is rapidly increased by the addition of pyridoxine to

the basic medium (Figure 1), and reaches the rate of growth of the
wild type at a. concentration such as to indicate that the a.bility
of the mutant to synthesize the vitamin is only about one percent
of that of the wild type.  A simple explanation of this observation
is tha.t the mutated gene of the mutant strain synthesizes an abnormal

enzyme, with decreased activity; if the a.bnorma.1 enzyme is manufactured
in amount equal to the normal enzyme, we may conclude that its
structural defect decreases its activity to one percent of that of
the enzyme manufactured by the wild type.

  The observed rate of growth of the "pyridoxineless" Neurospora

mutant as a function of the amount of pyridoxine added to the

medium, as reported by Beadle and Taturn, is shown in Figure 1.   The


Orthomolecular Methods in Medicine

Page Four

mutant equals the wild type in growth rate at vitamin concentration

10 microgra,ms per liter, and achieves a growth ra,te about 10 percent

higher for a four-fold increase in concentration.  We may draw the
conclusion tha,t the a.mount of the growth substance tha,t is synthe-
sized by the wild type is not the optimal a.mount, but is somewhat

iess.

In Figure 1 there is shown also the dependence of growth ra,te

on concentration of para-aminobenzoic acid for the mutant strain

of Neurospora  crassa that has decreased power to manufacture this

substance, and also the growth ra,te of the wild type of Neurospora

crassa. as a function of the a,mount of a growth substance, biotin,

that it is unable to synthesize.  These two growth-rate curves a.re

similar in form to that for the pyridoxineless mutant (of Keurospora
sitophila,),  and also similar in form to the theoretical curve that

is shown.  This theoretical curve represents the Michaelis-Men-ten
equa,tion, _R = _R,c"/(c_ + _K), in which ,R,, is the limiting rate for

high concentration of the reactant in an enzyme-catalyzed reaction,

2 is the concentration of the reactant, and 5,. the Michaelis constant,

is the assumed dissociation constant of the-complex of reactant and

enzyme.  The two lower calculated curves in Figure 1 correspond to

the same value of _R= and to values of K ten-fold and fifty-fold

greater, that is,  to a ten-fold and fifty-fold decrease "I
combining power of the enzyme for the reactant molecule.


Orthomolecular Methods in Medicine                 Page Five

The studies of the abnormal hemoglobins and of the many

inborn errors of metabolism show that human beings differ from one

another in their genetic constitution and the nature of the enzyme

molecules and other protein molecules that they synthesize.   Let

us consider the functioning, physical or mental, of a, "normal"

person, itf.~+~~~$?the amount` of a. particular vitamin
      g -$F

(th ia.mine, nicotinic acid, pyridoxine, ascorbic acid, or some other

vitamin) that he ingests.  We may compare him with the p:C@idoxineless
                               d

strain of Neurospora sitaphila.,  and conclude that his functioning

will depend upon the amount of the vitamin that he ingests.   If we

use the Michaelis-Menten curve as the basis for our description,

and take the rate of the enzyme-catalyzed reaction as a measure of

his state of well-being, we may say that he will show signs of poor

health (poor state of well-being, less than fifty percent of the
maximum) if he ingests less than 2 units of the vitamin per da.y
(using the scale for the horizontam axis of Figure l), that he will
have what probably might be called normal health (eighty percent of

the maximum) if he ingests ten units per day, even better health
(ninety percent of the maximum) for twenty units per day, and a

small but perhaps significant further increa,s.e in health for a, la.rger

amount of vitamin ingested.  Here the possibility must be kept in

mind that for large amounts of the vitamin some deleterious side

reactions could occur.  This possibility would be shown, for example,

by the observed toxicity of large amounts of the vitamin.   It is

interesting in this respect that some vitamins are essentially


Orthomolecular Methods in Medicine

Paae Six

        non-toxic.  Ascorbic acid and nicotinic acid a.re examples of vitamins q* fj

      4  tha,t are not toxic when taken in amounts of the order of 100 gra.ms,&@%L~
  A$) 1000 or 10,000 times the usually recommended daily requirement. h&-&&
W&&person who is homozygous in a, mutant gene, such that the enzyme
    that is manufactured under its control has a. combining power  for
    the vitamin that is only two percent as great as that of the normal

       enzyme.  The state of health of this person would be represented
    by the lowest of the three theoretical curves shown in Figure 1. If
    he received the normal ten units per day of the vitamin, he would
    be in the region of vitamin deficiency, with reaction rate only one-
     tenth of that of a, normal person on the same diet.   To be raised to

     the normal level of well-being, eighty percent of the maximum, he
    would need to receive fifty times the normal amount of the vita,min,
    500 units per day instead of ten units per day.  (Similar conclusions
     may be reached if the vitamin functions not a,s the reactant in an

enzyme-ca.ta.l":'tzed reaction,
         0'         but a,s ,g& :.-.-.& L..--+ '-'.. .h--'-,:- .:".- .__.._ ,.'. &enz.yme,
with the mutated a.po-enzyme having a decreased combining power for

We are accordingly led to the conclusion that some molecular

diseases might be controlled by the increase in the concentration
in the huma,n body of molecules that are normally present in the body,

/"'

and are normally require&for life and good health.   These molecules
might be molecules of vitamins, as discussed above, molecules of

a.mino acids, or molecules of other substances normally present in

the human body.


Orthomolecular Methods in Medicine                      ?a.ae Seven

                         r
The treatment of disease and the prevention of disease u

tne present time are largely accomplished by the use of synthetic
drugs or physiologically active substances-Lxtraacted from plants;

tha.t is, by chemotherapy.  Mental disease is controlled by
synthetic drugs such as chlorpromazine or powerful natural products

such as reserpine.  Electroconvulsive therapy, insulin coma

therapy,

changing

patients

methods,

pentoline?etrezol shock therapy ,  and related methods of

the structure of the brain are a.lso used.  In addition,
with mental disease may be treated by psychotherapeutic

+ Uo provide insight and to decrease environmental stress.

   We may use the expression orthomolecula,r medicine to describe

the general method of treatment and prevention of disea.se referred

to above, the provision in the right concentra,tion of the molecules

that are normally present in the human body and are needed for life

and good health.  (The word orthomolecular might be criticized as

a. Greek-Latin hybrid; I have not, however,  found any other word that

expresses so well the idea of the right molecules in the right amounts.)
  An example of orthomolecular therapy is the use of very large

amounts, five grams to twenty-five grams per day, of ascorbic a.cid

in helping to control colds and other infectious diseases.   The

treatment of diabetes by injection of insulin might also be considered

to be an example of orthomolecular medicine.  Another example is the
trea.tment of phenylketonuric children by use of a diet containing a

sma,ller than normal a.mount of the amino acid phenyla.la.Cine.  Phenyl-
ketonuria results from a genetic defect that leads to a, decreased


Orthonolecula,r Nethods in Medicine

Pa.ge Eight

amount or effectiveness of the enzyme catalyzing the oxidation of

phenylalanine to tyrosine.  The patients, when kept on a, normal

diet, have in their tissues abnormally high concentrations of

phenylalanine and some of its reaction products, which cause the
mental and physica, manifestations of the disease (mental deficiency,
severe eczema, etc.).  A decrease i-n the amount of phenylalanine

ingested in the food results in an approximation to the normal or

optimal concentrations and to the alleviation of the manifestations

of the disease, both mental and physical.

   In the case of phenylketonuria the concentrations of substances

in the pa.tient are la,rger than the optima.1 concentra,tions, and the

orthomolecular therapy requires a diminution in the concentrations.

This is more difficult to achieve than the increase in the concentra-

tions of ascorbic acid or insulin, mentioned above.   I believe that
there are several general arguments that can be presented in support

of the contention that most patients with a disea.se that can be

treated by the methods of orthomolecula,r medicine are in the second

category,  such that the treatment involves the increase in the amounts

of certa.in molecules, rather than in the more difficultly treatable

first category.

   One argument hams alrea.dy been given.   Geneticists have observed

that favorable mutations occur far more rarely than unfavorable

muta.tions :  the enzyme manufactured by a mutated gene almost always

shows decreased activity, relative to that of the wild type.   From

the argument given above we conclude tha,t the orthomolecular therapy

for such a disease would involve an increase in the amount of the


Orthomolecular Methods in Medicine

PaEe Nine

substrate for the reaction catalyzed by the enzyme, to bring the

ra.t.e of the reaction ba.ck towards normal,  or possibly the provision

Of the enzyme itself.  (I do not know of any disease that can be

treated by providing the enzyme itself, although in the case of

insulin therapy a closely similar trea.tment is involved, the

provision of the hormone itself,  identical with human insulin or

closely similar to it.)

Also, the exa,mple of the pyridoxineless strain of IYeurospora,

in rela.tion to the wild type (Figure l),  shows that the wild type

does not manufacture the optimal amount of the essential substa.nce

pyridoxine, but a,n amount a-~&$&& _ -- less than optimal.

We ma.y explain this observa.tion by considering the processes involved

in the, evolution of species.  The machinery for manufacturing the

essential substance is itself a. drain on the organism.  Presumably

the amount of drain on the organism increases roughly proportionately

to the rate of manufacture of the substance.   The differentia,l

disa.dvantaflge associated with a small increase in the amount of

synthesizing machinery is presumably balanced in the wild type by the

differential a.dva.ntage resulting from the larger amount of the growth

substance,  pyridoxine, that is synthesized; that is, the slope of the

growth-rate curve in Figure 1 at the concentration 10 micrograms per

liter, where the growth ra,te of the mutant is equal to that of the

wild type, is just, with changed sign, the differential disadvantage

associated with increase in the synthetic machinery.   Some increase

in well-being can accordingly be expected  through the increase in


Orthomolecular Methods in Medicine                 Page Ten

concentra.ti on even of substances that are not essential nutril-ites.

   In the case of vitamins and other essential nutrjlites, we
may consider the evolutionary process resulting in the-loss of the

ability of the organism to manufacture the substance.   Let us

assume that the substance is available .in the food normally accessible

to the organism, but in amounts somewhat less than the amounts

manufactured by wild type.  A muta.nt organism unable to manufa,cture

the substa.nce would be liberated from the drain associated with the

ma.chinery of manufacture.  The advantage accompanying this liberation
could outweigh this disadva.ntage accompanying the somewhat decreased

concentration of the substance.  Accordingly,  the mutant would

replace the wild type even though the concentration of the essentia.1
substance provided by the food normally ingested were somewhat less
than the concentration manufactured by the wild type.   Increase in


state of health would accordingly result from an increased supply
of the vitamin or other essential nutr&ite.

   Moreover, fluctuations from the normal situation might result in
an increased need for the nut&kite; an example is the state of

infection, mentioned a,bove,  that leads to an increased need for ascorbic


acid.  Ascorbic acid is required for the proper functioning of the

leucocytes of the blood, and an increased amount of ascorbic acid is

required for the proper increase in the number of functioning
leucocytes made in the effort to control the infection.

Orthomolecular psychiatry may turn out to be an important bra.nch

of orthomolecular medicine.  It has been reported, for example,


Grthomolecula,r Methods in Medicine                 Pa.ge  Eleven

that the ingestion in amounts of five to fifteen grams per day of

L(+)-glutamic acid, in a,ddition to the amounts provided by the normal

food, by patients with mild mental retardation leads to d. significant

increase in intelligence and significant improvement in personality.

This sort of orthomolecular therapy, which was discussed by.. variou`s
                       P

investiga;tors some twenty-five years ago, seems not to be used at

present to the extent that would seem to be justified by its simplicity,
freedom from dangerous side effects, and low cost.

   Another aspect of orthomolecular psychiatry that, in my opinion,

deserves more attention than it has received is the treatment of

schizophrenia and other forms of mental illness by the ingestion of

three grams to fifteen grams per day of nicotinic acid or nicotinamide
as well a.s of three to six gra.ms per da.y of ascorbic acid.9  These

substances are non-toxic and cheap, and they are normally present

in the human body.  The reports of great improvement in mental health

accompanying their use, together with the rationale for this sort.of

thera,py that has been developed in the arguments of the present paper,
suggest that a, thorough study of the effectiveness of this thera.py

  should be carried out.  I believe that for those patients for whom

it is effective the control of mental disease by varying their con-

centrations in the brain of non-toxic substances that are normally

                             tie&
present, such as nicotinic acid, nicotinamide, ascorbic acid ,p(+)-
gluta.mic acid, is to be preferred to the use of phenothiazenes and
other means of therapy that involve a greater insult to the body and

mind.


Grthomolecula,r Nethods in Medicine

Page Twelve

There are many other orthomolecular treatments that need to
be given a. thorough trial. The mental deterioration accompanying
a.ging and cerebral vascular disease may be a.lleviated by.supple-
mentary bioflavonoids (vitamin P) and ascorbic a.cid.  The -use of
cyanocobalarnine (vita.min 512) in the treatment of mental disease
ha.s been reported, as has also the use of pyridoxine (vita.min 36).
The study of the functioning of the brain in its relation to the
concentrations and intake of the vitamins, the essential amino acids >
non-essential amino a.cids,and other substances normally present
in the human body constitutes a field of research in which a, great
amount of work needs to be done.

End


Legend for ?iguye

Figure 1.  The top curve, with the associated points, represents

the experimental measurements of Beadle and Tat-urn  of the ra,te of

growth (centimeters per day) of the pyridoxineless mutant of

Keurospora  sitophila,,  as a function of the concentration of

pyridoxlne added to the basic culture medium, in micrograms per
liter (horizontal scale).  The second curve is the growth rate

        f-3
of the amino nenzoateless mutant of Keurospora crassa,, as a function

of the concentration of para-aminobenzo,&&  acid a,dded to the

medium,  same scale; the third curve from the top is the growth rate
                                            concentration of

of Neurospora crassa as a, function of the e
:                  -~~l--~,d &io$in %...: 1 1

t
-t"i:: the  medium , ,'- .:       ._ :.
                             .,.  (47 micrograms per liter on the
scale corresponds to 1 microgram per liter-of bio&in added).

The fourth curve from the top is the theoretical Michaelis-Menten

curve,  described in the text,  and the fifth and sixth curves from

the top are the theoretical curves with tenfold and fiftyfold

decrease in combining power of the enzyme for the substra.te,

respectively.  The large circle on the upper curve indicated the

growth r t                                  fi
     a e of the wild type of Neurospora sitophi,&, on

medium without aded pyridoxine.  The experiments1 values

top curve are from Referencea, thosee for the next curve

E. L. Tatum and G. W. Beadle, Trot.  Natl. Acad. Sci. I7.S.
                                         --                    -

the

for the

from

28
#'

234 (1942), and those for the third curve from the top  cz from

3'. J. Ryan, G. W. Beadle, and E;Y, L. Tatum, Am. J. Bot. 30, 784
                                                  -&
(1943) -