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177   The Big Fuss Over MSG
      The Washington Post  November 8, 1969

      Monosodium Glutamate (MSG) is about the last substance in the
world that any student of biochemistry would have expected to see
under attack as a food additive.  It is the sodium salt of glutamic
acid, among the commonest of the amino acids, making up, for example,
over a fifth of the composition of milk protein.  However, it is not
an essential part of the animal or human diet, but only because it is
synthesized in large amounts within the body.  Besides its role in the
structure of proteins, glumatic acid is an important intermediate in
metabolism, involved in basic reactions by which nitrogenous compounds
are cycled.

     More recently, glumatic acid has been found to have a special
role in the energy supply to the brain, where it is unusually abundant.
Speculations based on this finding led to fruitless trials
some years ago in which extra glumatic acid was fed to children of
low or borderline intelligence without effect.

     For several decades, MSG has served as a flavor-enhancer for
hamburger and the like; then it crept into baby foods, apparently
more for the benefit of the mother's than the infant's gustatory
enjoyment.

     The first reports that MSG might need some second thoughts 
came out as the near-joke of the "Chinese Restaurant Syndrome,"
a subjectively unpleasant reaction experienced by various people
to a rather large doses like five grams of MSG in won-ton soup.
Why some of us (like the writer) do not respond to moderate doses
is unknown. That the reaction was unnoticed for so long should 
provoke us to wonder how many similar adverse reactions to common
dietary substances remain to be discovered.

     Last May, Dr. John W. Olney of the Department of Psychiatry,
Washington University Medical School, in St. Louis, reported that
newborn mice suffered specific brain damage from injection with a
very large dose of MSG, a level that would be equivalent to 35 grams
in the adult.  Subsequently rats, rabbits and one monkey were reported
to show similar responses, mainly in the hypothalamus - a part of the
brain concerned with the regulation of hormones, of temperature, and
of body weight. Dr. Olney quite properly suggested that these findings
invited a reconsideration of the use of MSG, particularly in baby
foods.  However, so long as only modest amounts of MSG are used, small
in relation to the glutamic acid normally furnished by the rest of the
diet, it is  hard to see any basis of concern.  On the other hand, MSG
is entirely dispensable in infant diets - and together with salt and
sucrose it may be suspected of setting up invidious tastes that at
best do the young child no great advantage.

     The fuss about MSG as a food additive may be obscuring the deeper
interest of Dr. Olney's finding. It is startling that a natural amino
acid, even if only at high levels, can cause serious disease in a 
specific part of the brain--and it will be very surprising if this does
not have important implications for both further research and in 
understanding some kinds of brain damage that may be related to 
"normal" glutamic acid metabolism without our knowing it. The toxicity
of MSG reminds one of the effect of another amino acid, phenylalanine,
that can only be observed in the rare genetic disease, PKU,
which can often be treated by careful dietary control.

     We know very little about the blood levels of glutamic acid that
may obtain in the fetus or in some infants under various conditions.
We also have to look into the chance that other brain structures may
be more sensitive to MSG overdosage at other stages of development.

     MSG toxicity may also be related to an imbalance of its 
concentration compared to other amino acids, or also to its conversion 
to GABA (gamma-amino-butyric acid), an important transmitter substance
in the brain.  Until we have answer to these questions, we should
neither shrug off the possibility that Dr. Olney has discovered 
another important diet - related disease, nor be content with driving
MSG out of baby foods as a real response to the challenges he
has raised.
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