Consumption of monosodium glutamate (MSG) has been linked in studies to negative health effects such as obesity, diabetes, and metabolic syndrome. The concern with MSG is that it contains glutamate, which when consumed in high doses, can act as an excitotoxin or neurotransmitter known to kill brain cells. Certain people claim to experience headaches when consuming MSG, as well as other averse symptoms like muscle tightness, numbness, tingling, weakness and flushing. Studies have not been able to consistently reproduce these effects in a controlled setting. Overall, consuming small amounts of MSG is unlikely to cause harm for most people. However, as with any food additive, individuals who are sensitive to MSG or have underlying health conditions should be aware of their total consumption.