A Chinese Restaurant Syndrome Serves Glutamates

Last Saturday an Italian cook tried to kill me with flavours so intense I told my work colleague sitting just in front of me - This is the best food I had in a restaurant, ever!

The taste was incredibly intense, so particular, so lively that I surrendered to the Chef and gave away all predicates of quality I had in my hedonistic glossary. But it didn't take more than 60 minutes to understand that something was going wrong with my systems. I felt a sudden heavy weight like I wasn't able to lift up my head, a muscular weakness, palpitations, numbness and tingling in my hands, cold sweats, hot face and a range of specific vestibular system problems like disequilibrium, unsteadiness and spatial disorientation. I started stressing out when the most worrying symptom of all emerged - slurred speech. 

After many different diagnostics produced by my stressed-out brain I got to only two possible options, either something serious, discarded almost immediately because I exercise, I don't drink alcohol or smoke, I do gym twice a week, I monitor my health yearly and I believe there is some divine entity taking care of the good ones (regardless of that being a God or quantum matter), OR maybe something I had already experienced in the past.

The unexpected stroke me and I had to go deep into my memory lane to recall a similar situation lived when I was in my early 20s. I was then savouring the mystical delicacies in a Chinese restaurant in Faro (Portugal). 

Diagnosis: Monosodium Glutamates (clap clap clap, standing ovation, they deserve because you don't even know they're coming and once stricken it's like a multiple bee sting)!!! The typical symptoms produced by a meal 'rich in MSG" already gained a historical stamp - The Chinese Restaurant Syndrome (no need to say why, I guess)!

Also known as Ajinomoto, monosodium glutamates are the world's most extensively used food additives present in processed foods. These flavour enhancers were used up to around 600 mg/day per general individual back in 1991 (in the UK alone) [1]!!! The review article by Husarova and Ostatnikova on the toxic effects and health implications of MSG for humans is full of in-depth information that you must read about [2].

Since glutamate is the excitatory neurotransmitter in the mammalian central nervous system it plays an active function in the neuronal processes. Let us then look at effects already scientifically recognised as damaging to a brain exposed to high doses of glutamates:

a) Neuronal necrosis in hypothalamic arcuate nuclei in neonatal rats [3];

b) Potential connections between MSG and obesity due to increased palatability of food and disruptions in the hypothalamic signalling cascade of leptin action ('the hunger hormone') [4];

c) A portfolio of expression of inflammatory signalling molecules like increased mRNA expression of interleukin-6, TNF-alpha, resistin (peptide hormone linked to obesity and insulin resistance) and leptin, and incipient nonalcoholic steatohepatitis (inflammation of the liver with concurrent fat deposition in the organ) [5]; all of these factors contributing to inflammation which overall is terrible news for anyone dealing with any type of autoimmune disease;

d) Impaired glucose tolerance [5] (a pre-diabetes state where sugar levels in the blood are close to the typical in diabetics).

But what about any Antidotes that can be used to counteract the excitotoxic effects of MSG in our body? Well, recent research has brought up some very interesting substances. For me, personally, the most interesting ones were those revealed by Sudha et al (2016) [6] whilst offering us a really impressive article unveiling possible antidotes, namely: Hesperidin (a natural antioxidant) and Memantin (a drug used to treat Alzheimer's). Hesperidin is a bioflavonoid found in citrus fruits. And to be fair  there is also data available out there that state that Vitamin C has been showing a protective role against toxic nerve cell and astrocyte glial fibrillary acidic protein damage in cerebellar cortex in male albino rats [7]. But luckily many other vitamins have elicited protective roles against the excitotoxic effects of MSG, such as vitamin E (200 mg/kg) and the plant pigment flavonoid quercetin (10 mg/kg) that can be found in green tea, apples, and in large quantities in Buckwheat tea.

Now I know how to fight it if I ever have to face it again. But the best approach is just to ask the chef if he is using glutamates, even before I consider the restaurant for a meal.

[1] Rhodes, J., Titherley, A. C., Norman, J. A., Wood, R. & Lord, D. W. (1991). “A Survey of the Monosodium Glutamate Content of Foods and an Estimation of the Dietary Intake of Monosodium Glutamate”. Food Additives & Contaminants, 8(5), pp. 663-72.

[2] Husarova, V. and Ostatnikova, D. (2013). "Monosodium glutamate toxic effects and their implications for human intake: A Review". JMED Research, 2013, pp. 1-12.

[3] Pelaez, B., Blazquez, J. L., Pastor, F. E., Sanchez, A. and Amat, P. (1999). “Lectinhistochemistry and Ultrastructure of Microglial Response to Monosodium Glutamate-Mediated Neurotoxicity in the Arcuate Nucleus,” Histology and histopathology, 14(1), pp. 165-74.

[4] He, K., Du, S., Xun, P., Sharma, S., Wang, H., Zhai, F. & Popkin, B. (2011). “Consumption of Monosodium Glutamate in Relation to Incidence of Overweight in Chinese Adults: China Health and Nutrition Survey (CHNS),” The American Journal of Clinical Nutrition, 93(6), 1328-36.

[5] Roman-Ramos, R., Almanza-Perez, J. C., Garcia-Macedo, R., Blancas-Flores, G., FortisBarrera, A., Jasso, E. I., Garcia-Lorenzana, M., Campos-Sepulveda, A. E., Cruz, M. & AlarconAguilar, F. J. (2011). “Monosodium Glutamate Neonatal Intoxication Associated with Obesity in Adult Stage is Characterized by Chronic Inflammation and Increased mRNA Expression of Peroxisome ProliferatorActivated Receptors in Mice”. Basic & Clinical Pharmacology & Toxicology, 108(6), pp. 406-13.  

[6] Sudha, N. B, Raju, A. B. and Ashok, A. (2016). "Effect of Memantine and Hespiridine on Monosodium glutamate induced excititoxicity in rats". Indian Journal of Pharmaceutical Education and Research, 50(2), pp. 361-367.

[7] Hashem, H. E., Safwat, M. D. and Algaidi, S. (2012). "The effect of monosodium glutamate on the cerebellar cortex of male albino rats and the protective role of vitamin C (histological and immunohistochemical study)". Journal of Molecular Histology, 43(2), pp. 179-186.


Upper image kindly taken from Amyotrophic lateral sclerosis, The muscular distrophy association, [https://www.mda.org/disease/amyotrophic-lateral-sclerosis/causes-inheritance]. 

Lower image kindly taken from Health 24, In Chinese Restaurant Syndrome a thumbsuck?, [http://www.health24.com/Columnists/apparently-there-is-no-chinese-restaurant-syndrome-20160126].