But while some people assume the symptoms they’re feeling are the result of an allergy, an MSG reaction is really more of a sensitivity than a true allergy. According to Andy Nish, MD, a board-certified pediatrician and allergy-immunologist practicing in Gainesville, Ga., the difference between an allergy and a sensitivity is the involvement of a protein called IgE, an antibody that works in the allergy department of your immune system. True allergies, like pollen or pet allergies, are IgE-mediated. A sensitivity to MSG is not. It can seem like an allergy because symptoms arise after exposure to the offending ingredient. But without IgE involvement the reaction can’t be called a true allergy.
MSG Allergy Versus Sensitivity: Why Does It Matter?
Distinguishing between an allergy and a sensitivity is important because the treatment for each is different. The science behind allergies is fairly well-understood. There a number of treatments for symptoms, including medications and injections. The science behind food sensitivity to MSG isn’t as established. Glutamate, the main ingredient in MSG, is a neurotransmitter — a chemical that carries messages in the nervous system. Scientists have been searching for a link between glutamate in the nervous system and the symptoms of MSG sensitivity. But a connection has not yet been made. So for now, Nish says, avoiding MSG if it bothers you is the best thing to do. While MSG is best known for its use in restaurants, it can also be found in frozen meals, packaged snack foods, canned foods and soups, and even seasoning mixes. Check the ingredients lists on food labels. As a general rule of thumb, if you eat something that gives you a reaction you’ve had before you should eliminate that food from your diet.
The Bottom Line on MSG
Research hasn’t shown MSG to trigger allergy symptoms in large studies, but according to Nish, that doesn’t mean a sensitivity to the ingredient doesn’t exist. “No double-blinded, placebo-controlled studies have shown it to cause problems in a large number of people, [but] I’m sure it can cause this in certain people,” he says. So if you think you’re sensitive to MSG, figure out which foods trigger your symptoms and avoid them.
