My flatmates and I have developed an MSG addiction… Should we be worried?

A tale of brain damage and racism.

A few months ago, I walked into the kitchen to find my flatmate reclined in front of his laptop, an empty bottle of Aldi red swinging ominously by his side. He glanced up at me from behind one twitching eyelid and announced that we’d “gone far too long without MSG”, that he’d ordered a kilo of the pure stuff, and that it would be arriving the next day. In hindsight, it should have been obvious what was to happen next. Soon it was in everything; the roasts, the curries, the pasta, the risotto. We ate it on toast, and by the spoonful. A thin crystalline layer coated every surface like volcanic ash. The air we breathed was savoury, and I eventually began to wonder whether it was all such a good idea.

Umami, the savoury ‘fifth taste’ found in meat, tomatoes, and stock was first isolated in 1908 by Kikunae Ikeda, a Japanese chemist looking for the secret behind the flavour of kombu, a type of seaweed used to make miso and ramen soups. A long and tedious extraction process finally yielded the answer – glutamic acid. Glutamine is one of the basic amino acids encoded by DNA and its derivative, glutamate, is one of the most abundant neurotransmitters in the brain and is found to some degree in all high-protein food. Ikeda theorised that, in the same way that sweetness alerts us to the presence of carbohydrates, and bitterness to potential toxins, the umami taste must serve an evolutionary function in incentivising animals to consume protein. Having made his breakthrough, he set about trying to make the discovery marketable, eventually finding that combining the glutamic acid with sodium rendered it into a packageable salt without adversely affecting the taste. The company he founded to sell his newly patented product, Ajinomoto Inc., remains the lead exporter of monosodium glutamate, or MSG, to this day.

Myths and Facts - MSG - Unilever Food Solutions
Monosodium glutamate. Image: Unilever Food Solutions.

If you’ve heard of MSG, you’ve probably heard the bad stuff. The kind of people that worry about aspartame giving you cancer and mobile phones killing your sperm might have told you that it’s addictive and “messes with your brain”. This all started in 1968, by which point the mouth-watering, flavour-enhancing effects of MSG had led to it becoming a common additive in fast food, when the mysterious Robert Ho Man Kwok, M.D. wrote a letter to the New England Journal of Medicine describing his new discovery – “Chinese Restaurant Syndrome”. He relayed that he and many of his “well educated Chinese friends” had been experiencing muscle weakness, palpitations, and neck pain whenever they ate at Chinese restaurants. Despite the fact that he only passingly mentions MSG as a possible cause along with a range of other possibilities, it kicked off a nationwide panic in the US. The following year, a scientist named John Olney published a paper in Science showing that injections of MSG caused brain lesions and obesity in mice. He later repeated the experiment in monkeys and demonstrated that the effects were more severe in children, leading him to petition the FDA (Food and Drug Administration) to ban MSG in children’s food. He was ignored. People began to talk about “excitoxicity”, believing that the link between MSG and glutamate, an excitatory neurotransmitter, was causing brain damage by making neurons literally “fire themselves to death”. In another, more recent study, the diets of 752 villagers in rural China were assessed, of which 82% contained added MSG. The results showed that MSG intake was significantly correlated with an overweight BMI. 

“Injections of MSG caused brain lesions and obesity in mice”.

So far, it’s not looking great for me. However, it’s worth taking a closer look at where it all began. Media outlets that picked up the original “Chinese Restaurant Syndrome” story, being outsiders to the medical community, may not have realised that the correspondence section of the NEJM often hosted satirical or tongue-in-cheek discussions of cases that may or may not have actually existed, full of inside jokes intended only for other doctors. In her 2017 article ‘Uptaking Race: Genre, MSG, and Chinese Dinner’, Prof. Jennifer LeMuserier argues that not only was the original letter not medically serious, but that the discussion around it was framed by existing cultural fears around Chinese immigrants and products. She points out that the ‘strange and exotic’ nature of Chinese food makes it an easy target for accusations of being a health risk, when historical stereotypes towards Chinese people characterise them as shadowy figures prone to either insidious trickery or downright barbarism. The word ‘Chinese’ itself remains in use today to describe things that are surprising, wicked and confusing, as in ‘Chinese water torture’, ‘Chinese burn’, ‘Chinese finger trap’, and ‘Chinese whispers’. Perhaps even more so today than in the ‘60s, a feeling exists of Chinese cultural practices being anathema to Western medicine and hygiene, whether we’re talking about Wuhan wet markets or snow leopard aphrodisiacs, all of which serves to prime members of the public to buy into the idea that Chinese food really could be making you sick with its secret ingredients. Furthermore, after she published the article, LeMuserier was contacted by a member of her own university, Dr. Howard Steel, who claimed to have sent the original letter himself, confirming her suspicions that ‘Dr. Ho Man Kwok’ was a pun on ‘Human Crock’. Unsurprisingly, the Ajinomoto company has also taken action against Chinese restaurant syndrome, campaigning this year against Merriam-Webster to have the dictionary definition changed, and pointing out that the ingredient appears just as frequently in Western processed and fast food. 

stir fry noodles
Chinese food has come under fire by researchers claiming it contains high quantities of MSG. Image: Unsplash.

So, should we be pouring our special salt down the sink or resupplying? The findings of Olney’s study are worrying and have been replicated numerous times since. Whilst it’s true that to replicate the conditions that he exposed his mice to I’d have to inject myself with half the bag in one go, that’s not to say that an incremental intake doesn’t have an incremental effect, and the debate remains an area of active research. LeMuserier’s argument that the wider panic has a racist basis undoubtedly holds water, but it isn’t enough to invalidate the research that came after the inciting incident by itself. In addition, her central point that the original letter was never intended for serious discussion is still in dispute; following the death of Howard Steel, it was revealed that there was a real Dr. Ho Man Kwok, also recently dead, and both his and Steel’s families insist that, bizarrely, Steel was himself playing a prank by pretending to have made him up. But that shouldn’t matter – the data suggest that, like most things, MSG is fine in moderation. The more meaningful issue to be reminded of is that science isn’t carried out in a vacuum. Scientists are members of a wider society, are subject to the same cultural forces as everyone else and their work can be, and is, informed by prejudices and biases, either their own or those of the public, whose opinions affect the market within which they work.

By Finn Laslett

Header image: Pixabay