In healthy adults, four studies showed inconsistent results on the presence of reactions after ingestion of monosodium glutamate (MSG). In children or adults with chronic urticaria (two studies), ingestion of MSG did not worsen symptoms. In adults with asthma (two studies), ingestion of MSG did not worsen symptoms. 

• Grade I means there is Good/Strong evidence supporting the statement;
• Grade II is Fair;
• Grade III is Limited/Weak;
• Grade IV is Expert Opinion Only;
• Grade V is Not Assignable.
• High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
• Moderate (B) means we are moderately confident in the effect estimate;
• Low (C) means our confidence in the effect estimate is limited;
• Very Low (D) means we have very little confidence in the effect estimate.
• Ungraded means a grade is not assignable.