Is MSG bad for you, and should I cook with it?
What monosodium glutamate actually is, where the health scare came from and what the evidence says now, and how to use it in an ordinary kitchen if you decide to.
- Difficulty
- beginner
- Time
- 7 min
- Read
- 4 min
Short answer
MSG is the sodium salt of glutamate, the same amino acid that gives Parmesan, tomatoes, soy sauce and Marmite their savour. Regulators including the Food Standards Agency and EFSA consider it safe at normal levels. Use about a quarter teaspoon per portion, in place of some of the salt rather than in addition to it.
Few food ingredients have been as thoroughly investigated or as badly reported. Glutamate is present in almost every savoury food people already love, and MSG is simply a purified form of it with sodium attached. The story of why it acquired a reputation is worth knowing, because it explains why a safe and useful ingredient sat in a cupboard unused for forty years.
Step by step
- Understand what it is.Glutamate is one of the commonest amino acids in nature. It is what your tongue detects as umami. MSG is glutamate bonded to sodium, produced by fermenting starch — the same process that makes vinegar or yoghurt. Chemically, the glutamate from MSG and the glutamate from Parmesan are identical.
- Know where the scare came from.A letter to a medical journal in 1968 speculated about symptoms after eating at Chinese restaurants. It was speculation, not a study. Decades of controlled trials since — including double-blind challenges — have failed to reproduce a consistent effect, and the episode is now widely regarded as a case study in how a scare propagates.
- Know where the regulators stand.MSG is an approved food additive in the UK and EU, labelled E621. EFSA reviewed it in 2017 and set a group acceptable daily intake for glutamates, which typical dietary intakes sit within. The Food Standards Agency does not advise avoiding it. A small number of people report sensitivity at high doses; that is a fair reason for an individual to avoid it and not a reason for a general warning.
- Use it in place of some salt, not in addition.MSG contains roughly a third of the sodium of table salt for a similar seasoning effect. Replacing part of the salt in a dish with MSG can cut the sodium meaningfully while keeping the dish tasting full — which is why it appears in reduced-salt products.
- Start with about a quarter teaspoon per portion.It is easy to overdo. Too much gives a slightly chemical, lingering savoury note. A quarter teaspoon in a pan of soup for four is a good starting point. Add it early enough to dissolve, taste, and go from there.
- Use it where you would use anchovy, soy or Parmesan.Soups, stocks, gravies, tomato sauces, mince, mushroom dishes, marinades, roast vegetables, chips, popcorn. It does very little in sweet dishes and it does not replace acid, fat or salt — it is one lever among five.
- Or get the same effect from whole ingredients.A Parmesan rind, a squeeze of tomato purée cooked out, an anchovy melted into the base, dried mushrooms, miso, fish sauce and Marmite all deliver glutamate along with other flavours. If you would rather not keep a tub of MSG, these are doing the same job.
Tips
- Glutamate and the nucleotides in mushrooms, dried fish and cured meat multiply each other's effect. MSG plus dried mushroom is far more savoury than either alone, which is the principle behind dashi.
- It is sold as 'flavour enhancer', 'seasoning' or under brand names in most large supermarkets and in every Asian grocer, usually very cheaply.
- It does not make bad food good. A dish that is short of acid or fat will taste savoury and still wrong.
- If you or a guest prefer to avoid it, that is easy to respect — but be aware that yeast extract, stock cubes, soy sauce and mature cheese all deliver free glutamate anyway.
- Store it dry and sealed. It clumps if it gets damp, like any fine salt.
Questions people ask
Does MSG cause headaches?
Controlled trials have consistently failed to reproduce headaches or other symptoms when MSG is given blind, including in people who identify as sensitive to it. Some studies find effects at very large doses taken without food, which is not how anybody eats. Individual sensitivity cannot be ruled out and anybody who notices a reliable effect should avoid it, but there is no good evidence of a general risk.
Is MSG worse than the glutamate in Parmesan or tomatoes?
No. Your body cannot distinguish them; free glutamate is free glutamate whatever its source. A tomato, a mature Parmesan, a splash of soy sauce and a pinch of MSG all deliver the same molecule. Ripe tomatoes and aged cheeses contain substantial amounts naturally, which is exactly why they taste savoury.
Will using MSG reduce the salt in my cooking?
It can. Weight for weight MSG contains around a third of the sodium of table salt while giving a comparable savoury effect, so replacing part of the salt with a smaller quantity of MSG lowers the sodium in the dish. That is a recognised reformulation technique in the food industry and it works at home too, as long as you replace rather than add.