Excessive intake of monosodium glutamate is a vision killer, which will lead to the decrease of protein -3 and make the growth of eye axis out of control. MSG can also reduce taurine in human body and affect the development of retina, and even some people will have temporary blurred vision after eating MSG. Eating too much monosodium glutamate is harmful to your health. Many people are used to putting monosodium glutamate when cooking. However, according to a recent survey in Taiwan Province Province, about 30% people suffer from lethargy and anxiety due to excessive intake of monosodium glutamate. The main component of monosodium glutamate is sodium glutamate, which can be decomposed into glutamic acid during digestion, and the latter is converted into an inhibitory neurotransmitter by enzyme catalysis in brain tissue. When monosodium glutamate is ingested too much, this inhibitory neurotransmitter will inhibit various nerve functions in the human body, resulting in a series of symptoms such as dizziness, headache, drowsiness and muscle spasm. Some people will be anxious and flustered; Some people with sensitive physique may even feel sore bones and muscles. In addition, excessive inhibitory neurotransmitters can also inhibit the secretion of thyroid stimulating hormone in human hypothalamus, thus hindering the development of bones, especially for children. Eating too much monosodium glutamate often makes you thirsty. This is because monosodium glutamate contains sodium, and excessive intake will lead to high blood pressure. People over the age of 60 are particularly sensitive to sodium intake, so the elderly and people suffering from diseases such as hypertension, kidney disease and edema should especially eat less monosodium glutamate. When the consumption of monosodium glutamate exceeds the metabolic capacity of the body, it will also lead to an increase in the content of glutamic acid in the blood, limiting the use of essential minerals such as calcium, magnesium and copper. In particular, glutamic acid can combine with zinc in blood, and the unusable zinc glutamate is excreted, resulting in zinc deficiency in human body. Zinc is an important nutrient for infants' physical and intellectual development. Therefore, infants and nursing mothers should fast or eat less monosodium glutamate. In addition, Japanese researchers believe that long-term excessive consumption of monosodium glutamate may lead to thinning of retina, decreased vision and even blindness. So, how much monosodium glutamate is appropriate for each meal? The researchers suggest that each dish should not exceed 0.5 mg. The severity of the side effects of monosodium glutamate will vary according to one's physique. Therefore, everyone should pay attention to health while enjoying delicious food.