Umami, the oft-maligned fifth taste sensation

Human taste buds evolved with the ability to detect five distinct tastes. Salty, Sweet, Sour, Bitter and Umami. But what is umami ?

Umami comes from the two Japanese words “umai”, meaning “delicious” and “mi”, meaning “taste”. It has long been identified as a savoury, brothy or meaty flavour that coats the taste buds and lingers long after the meal has finished. It was originally thought to be triggered by the presence of the amino acid L-glutamate, but in 1913 Japanese professor Kikunae Ikeda identified that some foods containing ribonucleotides combine with the salted form of glutamic acid to produce a flavour this is more than the sum of its parts. In particular, umami enhances the taste of salt, enabling low-salt foods to taste more delicious without the harmful addition of extra sodium.

Umami flavour has a long history in cooking. Fermented fish sauces in Ancient Rome were known to trigger this taste. French chefs in the 1800’s were combining umami-containing foods with other flavours such as salt to produce a more intensely pleasing flavour. In Italian cooking, the combination of parmesan cheese with mushrooms was known to trigger heightened enjoyment of a meal. In Japanese cooking, seaweed and shitake mushrooms were used to stimulate this sensation, and in Chinese cuisine the addition of Chinese cabbage and leek to chicken soup was known to enhance the flavour of a meal. In American cooking, the umami flavour is found in the most common ingredient imaginable; ketchup. Variations of the individual compounds in MSG that produce the umami sensation exist in so many common foods including meat, wheat, spinach, corn, tomatoes, mushrooms, cabbage and milk. Indeed, it could not be argued that umami is unnatural because it is contained in human breast milk, making babies find it delicious and satisfying, making them both want more, but at the same time leaving them with the delicious lingering flavour in their mouth.

Molecular and biochemical scientists have studied our taste receptors and confirmed that consuming umami triggers the release of calicum, beta-gamma proteins, and it even causes us to produce more serotonin, the neuro-chemical which makes us happy and is most commonly used in anti-depressant medications. Our taste buds have evolved to make us crave the foods which give us the essential proteins we need to survive by making us appreciate foods including salts, sugars and the savoury taste of umami.

The flavour of umami is often added artificially to our food, particularly in Asian cuisine, but when you say the name of the food additive which creates the sensation of umami, many people cringe in fear and start panicking and talking about carcinogens and headaches and dizziness and lethargy and all sorts of other ailments. Why ? Because the most common way to add umami flavour to a meal that does not naturally contain it is with Mono Sodium Glutamate, commonly known as MSG.

In Vietnamese cooking we refer to it as “bột ngọt” or “sweet powder” although the taste is not actually sweet but savoury. In Japan, they simply call it umami essence. When you call this food additive it by its chemical name “mono sodium glutamate” people find the name alarming, but if we referred to table salt as “sodium chloride”, wouldn’t people equally think of this as scary-sounding chemical ?

We are bombarded with dietary advice such as “avoid sodium rich foods” and we all know that too much salt is bad for us due to its artery-clogging potential, but it is for this reason that MSG is actually such a wonderful substance as it combines two different substances in small amounts to produce a flavour that is more intense than each on their own and it allows us to produce more flavour with less of the other harmful additives.

The hype and fear about MSG originated in 1968 when a largely uncredited Chinese-American physician wrote a light-hearted letter to The New England Journal of Medicine wondering if the “numbness, palpitations and weakness” he observed up to two hours subsequent to eating at a local Chinese restaurant could be attributed to the MSG used in the meals. Unfortunately this letter caused a massive sensation in America, causing this popular additive which had been used since the 50’s to be pulled from the shelves, removed from foods and incorrectly labeled as a “toxin”, despite having an LD50 rating (the measurement used to describe how much of a substance is considered a lethal dose to 50% of test subjects) lower than that of table salt.

By the 1970’s it had crept back into many foods under different names such as hydrolyzed proteins, yeast extracts, protein concentrates and various additives and flavour enhancers known only by numbers but which scientists confirmed were all essentially just synthetic glutamates.

More recent studies by neuro chemical scientists such as Dr. Nicholas Maragakis and Dr. Jeffrey Rothstein found that MSG has no connection to claims of neurological damage or migraines, even when eaten in large quantities. A nutritional scientist Dr. Stevenson confirmed that MSG could not linked to increasing or worsening the effects of asthma as was commonly believed, and in 2009, the Clinical & Experimental Allergy journal wrote that a decade of study had shown no verifiable proof that MSG caused any allergic reactions or harmful effects.

It is surely a failing of our educational systems and a willingness of the general public to listen to hype and speculation rather than hard facts that this wondrous compound which gives us such pleasure without the harmful effects that too much sodium and the other amino acids and salt compounds on their own would induce is so maligned. Instead, we live in fear of a scary sounding chemical name and some long-disproven rumours created by a speculative and half-serious letter of opinion by a physician over 40 years ago.

Nutritional science has proven that the combination of ribonucleotides and glutamates in MSG work in amazing ways on our taste receptors and gives us heightened pleasure from our food that each on or their own do not produce. So let’s put these misconceptions behind us and accept MSG for what it is; an amazing food additive that allows us to enjoy our food without the harmful effects of less effective flavour enhancers. Embrace bột ngọt in your cooking and savour the wonderful sensation of umami that we evolved to appreciate for good reason. You’ve been enjoying it since you were on your mother’s teat so don’t let one misleading letter to a magazine half a century ago spoil your enjoyment of this delicious flavour.


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