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Master
the ABCs of MSG
Aug. 09, 2007
Suzanne Havala Hobbs
Do
you know the ABCs of MSG?
Monosodium glutamate – or MSG, for short – is
a form of glutamate, a naturally occurring amino acid, or
building block of protein, found in our bodies and in protein-rich
foods such as dairy products, meats and legumes.
It’s used as an additive to bring out the natural flavors
in certain foods – soups, salad dressings, frozen entrees
and restaurant foods, for example – even though MSG
itself has no flavor. Scientists aren’t sure how it
works, but it’s possible that MSG stimulates glutamate
receptors in the tongue to produce a sort of “fifth
taste” in addition to salty, sweet, sour and bitter.
That fifth taste is called “umami” in Japan, where
MSG was originally extracted from seaweed. In this country,
we describe the taste as “savory.”
Today, MSG is made by fermenting starch, sugar beets, sugar
cane or molasses. In appearance, it resembles salt or granulated
sugar.
Years ago, I ventured a peek into the kitchen of a Chinese
restaurant where a friend worked and spied next to a stovetop
a wok piled high with white stuff. In the frenzy of the busy
kitchen, hands would occasionally reach for a fistful of the
MSG and toss it into the skillet.
This tradition of adding MSG to Chinese food led in the late
1960s to an observation that for some people, added MSG in
foods causes headache, nausea, weakness, heart palpitations,
flushing and a burning sensation on the back of the neck.
The reaction became known as “Chinese restaurant syndrome.”
Since then, complaints about sensitivity to MSG have continued.
However, a systematic review of the scientific literature
conducted by scientists from the Federation of American Societies
for Experimental Biology (FASEB) in the mid 1990s concluded
that MSG is safe to consume at levels typically used in foods
(less than 0.5 grams per serving.)
What we don’t know is how little MSG it takes to produce
a reaction in MSG-sensitive people. And the report did confirm
that some people are sensitive. In addition to the symptoms
listed above, scientists found:
* In MSG-sensitive people, one or more symptoms often appear
within one hour of eating 3 grams or more of MSG on an empty
stomach, especially if the food is in liquid form, such as
soup.
* People with severe, poorly controlled asthma appear to be
at greater risk of developing symptoms.
* There is no evidence to link MSG use with other long-term
diseases such as Alzheimer’s disease, Huntington’s
chorea or ALS (amyotrophic lateral sclerosis, or Lou Gehrig’s
disease), nor with damage to nerve cells in humans.
So is MSG safe to use?
The answer appears to be yes, for most people.
But years of personal dietary detective work may lead others
to conclude they are sensitive to MSG. If you are among them,
you should:
* Read food labels. The Food and Drug Administration requires
that foods containing MSG be clearly labeled.
* Be aware of other forms of glutamate in foods, including
natural flavorings and hydrolyzed vegetable protein. There
is no evidence to suggest these cause the same symptoms as
MSG, but they are similar man-made substances. Seaweed, mushrooms,
Parmesan cheese and tomatoes contain naturally occurring glutamate
and have not been linked with reactions.
* Ask that MSG not be added to foods when you eat out at Asian
restaurants.
And most of us would do best to minimize our exposure to MSG
anyway, as a means to limit sodium intake. MSG contains less
sodium than table salt and is used in smaller amounts, but
it’s still a source of added sodium, which most of us
get in excess.
The best advice is to let the fresh, natural flavors of foods
stand alone.
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