It&#x27;s really crazy how common MSG is, and as a result it can be very difficult to diagnose an allergy. A friend of mine has a severe reaction to MSG (diarrhea, skin lesions, etc.), and it took years of misery before he figured out the cause.<p>It&#x27;s found naturally in many foods you wouldn&#x27;t expect (pears, cucumbers, tomatoes), and other times companies add it to unexpected items (Dole sprays it on bananas).