This popular flavor enhancer may
not be as harmful as we previously believed.
Monosodium glutamate (MSG) has long been associated with words
like "artificial flavors" and "trans fats"—as in, a
controversial ingredient. As of 2018, 10 out of 4 Americans said they were
actively avoiding it.
Even among dietitians, there is no complete consensus on the
safety of this addition. A recent email advertisement sponsored by MSG maker
Ajinomoto was sent to Academy of Nutrition and Dietetics members, urging them
to encourage their clients to use MSG as a salt substitute. Some dietitians protested
this recommendation (and the lack of who sponsored it).
Despite this, an increasing number of nutrition experts have
called for the stigma around MSG to be removed. Many people believe that
avoiding it is due to old information (and possibly even anti-Asian racism).
So, is this a dietary no-no or a good flavor enhancer? Here's
everything you need to know about it.
The history of MSG's bad rap
MSG's unsavory reputation can be understood with a bit of
backstory. It all started in 1968, when a letter reportedly from Dr. Robert Ho
Man Kwok appeared in the New England Journal of Medicine, expressing worry that
Chinese food had made him sick. He claimed that symptoms including headache,
dizziness, numbness, and weakness were caused by monosodium glutamate, which he
found in Chinese food. (It was later found that the letter was written as a
prank by an imposter.)
However, researchers took the idea and ran with it at the time. In
a 1969 study on mice, researchers discovered that high-dose MSG caused brain
lesions, obesity, and endocrine disruption. Further research suggested that the
additive could cause heart and liver problems, behavioral changes, and tumors.
MSG gained a reputation as an ingredient to avoid at all costs as these bad
ideas spread to the general public.
More accurate MSG research
In actuality, much of the early MSG research was riddled with
flaws. According to a 2020 study, most of the research that showed its claimed
negative impacts was affected by poor design and small sample size. In many studies,
individuals were given extremely high doses of MSG that would never be found in
a regular diet.
On the other hand, a recent study tells a different (and much more
positive) story. For example, you might be surprised to learn that MSG has been
categorized as "GRAS" (generally recognized as safe) by the Food and
Drug Administration (FDA) for several years. According to the FDA, science
hasn't been able to link MSG use to any harmful side effects consistently. The
most intriguing part is that this holds even in persons who profess to be
hypersensitive to MSG.
In terms of specific MSG reactions, the good news keeps coming. A
systematic review published in the Journal of Headache Pain in 2016 found no
link between eating foods high in MSG and headaches. You can also relax about
the effects of MSG on your brain. Despite some worrying claims that this
ingredient can induce brain cell death, scientific research reveals that MSG
does not cross the blood-brain barrier. The moral of the story: it's doubtful
that a dish of beef and broccoli will cause you to lose your mind.
The data isn't apparent when it comes to weight gain (another
common MSG fear). According to a review published in 2019, some studies have
found that high-MSG foods increase hunger and even promote obesity, while
others have found the opposite. The macronutrient content may influence whether
MSG makes you feel full or hungry.
What about MSG sensitivity?
MSG is considered safe for most people, although it is possible to
develop a sensitivity to it, just like any other food. MSG sensitivity affects
less than 1% of the general population. Large amounts of food may cause
unpleasant symptoms such as dizziness, headache, difficulty breathing, or
numbness in some persons. If you have symptoms like these after consuming
high-MSG foods regularly, you may wish to reduce your intake. Not sure if MSG
is the source of your problems? A food journal might be a helpful tool for
finding out what's going on in your life.
That said, you're likely eating MSG-containing items without even
recognizing it! Monosodium glutamate is found naturally in many foods,
including tomatoes, mushrooms, and old cheeses, and the body does not
distinguish between natural and synthetic forms. Your GI tract breaks down
sodium and glutamate in the same way, whether it comes from a fresh tomato or a
bowl of ramen.
The potential positives of MSG
Are you ready to change the way you think about MSG? Not only is
this far component not harmful to most people, but it may also have a
beneficial effect on your diet. With its savory umami flavor, MSG could be a
flavorful replacement for salt. (It only has a third of the sodium in table
salt.) MSG could reduce sodium without changing the perception of saltiness,
according to a 2017 study published in the journal Food Science and Nutrition.
There's plenty of reason to give MSG another opportunity, given all the evidence for its safety and the fact that so many of us tend to overdo it with the saltshaker.