Overview
Monosodium glutamate (MSG) is used as a flavor-enhancing food additive. It can have a bad reputation, as many believe it can cause allergy-like symptoms and side effects.
However, much of the evidence has relied on anecdotes and limited clinical studies. So what's the truth about MSG? Is it really as bad as it's been made out to be?
Evidence
Despite concerns, decades of research have failed to demonstrate a relationship between MSG and serious reactions for most people. People have reported reactions after eating foods with MSG, but researchers have been unable to scientifically prove the allergy.
In 2014, Clinical Nutrition Research did present a link between MSG and allergy reactions in a small subset of people who suffer from chronic hives. However, the majority of these reports involve mild symptoms, such as:
tingling skin
headache
a burning sensation in the chest
Larger doses of MSG have been found to cause symptoms. But those portions are unlikely to be found in restaurant or in grocery store food. After reviewing the evidence in 1995, the U.S. Food and Drug Administration (FDA) put MSG in the same "generally recognized as safe" category as salt and pepper. A 2009 review published in the journal Clinical & Experimental Allergy came to a similar finding.
The exception to the safety of MSG is more questionable in children. A 2011 study in Nutrition, Research and Practice revealed a link between MSG and children with dermatitis. However, further research is warranted to make a definitive statement about this connection.
Symptoms
Those sensitive to MSG may experience:
headache
hives
runny nose or congestion
mild chest pain
flushing
numbness or burning, especially in and around the mouth
facial pressure or swelling
sweating
More serious symptoms may include:
chest pain
heart palpitations
shortness of breath
swelling in the throat
anaphylaxis
Your doctor may ask if you’ve eaten any food containing MSG within the last two hours if they suspect you have a MSG allergy. A rapid heart rate, abnormal heart rhythm, or a reduction of airflow to the lungs may confirm a MSG allergy.
Treatment
Most allergic reactions to MSG are mild and go away on their own. More serious symptoms, such as anaphylaxis, require emergency treatment in the form of a shot of epinephrine (adrenaline).
Call your doctor and go to the nearest emergency room immediately if you experience one of the following symptoms:
shortness of breath
swelling of the lips or throat
heart palpitations
chest pain
The best treatment for a food allergy is to avoid eating that food. However, MSG is a prominent ingredient in many different types of food. According to the U.S. Department of Agriculture, MSG is found in virtually all food. It’s found in high doses in food that is high in protein, such as:
meat
poultry
cheese
fish
Labeling is only required when MSG is added as an ingredient. In those cases, it will be listed as "monosodium glutamate."
People with a true allergy to MSG should avoid packaged and processed foods. Instead, opt for raw foods including fruits, vegetables, and organic meats instead. Other substances to avoid include:
dried meats
meat extracts
poultry stocks
hydrolyzed protein, which may be used as binders, emulsifiers, or flavor enhancers
Food labels may refer to these products as "dried beef," "chicken stock," "pork extract," or "hydrolyzed wheat protein."
Outlook
A very small part of the population has a reaction to MSG. Most of those reactions are typically mild. Try avoiding the foods listed above if you suspect an MSG allergy. There’s a good chance that you’ll only experience mild discomfort even if you eat foods containing MSG.
It would be prudent for children and adults with complex medical histories to limit consumption of MSG until further research can confirm safety.
Your doctor may put you on a strict avoidance diet and prescribe an epinephrine shot if you’ve experienced severe reactions.
Source:
http://www.healthline.com/health/allergies/msg#Overview1
