MSG (Monosodium Glutamate): What It Is and Is It Safe?
MSG, or monosodium glutamate, is a seasoning made of glutamate, an amino acid, paired with sodium. Glutamate is the main molecule responsible for umami, the savoury taste in tomatoes, Parmesan, mushrooms, soy sauce and meat broths. MSG is simply that taste in a pure, crystalline form.
Where MSG came from
In 1908 Japanese chemist Kikunae Ikeda wondered why kombu broth tasted so deeply savoury. He isolated glutamate from the seaweed, named its taste umami, and began producing it as a seasoning. Today MSG is made by fermentation: bacteria convert sugars from corn, beets or cassava into glutamate.
Chemically, the glutamate in MSG is identical to the glutamate in a ripe tomato or aged cheese. Your body doesn't tell them apart.
What MSG does in food
- Adds savouriness. It makes soups, stews, sauces and vegetables taste fuller and meatier.
- Rounds out salt. Food with a little MSG often needs less salt to taste seasoned.
- Boosts other umami. Glutamate multiplies in strength when combined with inosinate (in meat and fish) or guanylate (in dried mushrooms). That synergy is why dashi, made with kombu and bonito, tastes so intense.
On its own, MSG tastes faintly salty and brothy, not much like anything. Its effect shows up in a dish.
Is MSG safe?
Yes, at normal culinary amounts, according to Health Canada, the US FDA and international food-safety bodies. The fear of MSG began with an anecdotal letter in the late 1960s. Later double-blind studies, where people didn't know if they'd been given MSG, failed to show consistent reactions at amounts found in food. A small number of people may notice mild, short-lived symptoms after very large doses on an empty stomach.
MSG also has less sodium than salt: about 12% versus 39%.
How to use it
| Use | Starting amount |
|---|---|
| Soup or stew (about 2 litres) | 1/2 tsp |
| 500 g ground meat or burger mix | 1/4–1/2 tsp |
| Vinaigrette (250 ml / 1 cup) | A pinch |
| Popcorn or fries | A light dusting with salt |
Add it with the salt, taste, and adjust. Too much makes food taste flat and synthetic.
Questions
Is MSG bad for you?
Health Canada, the US FDA and other food regulators consider MSG safe at normal amounts. Controlled, blinded studies haven't found that typical amounts cause the headaches and symptoms once called Chinese restaurant syndrome.
Does MSG have less sodium than salt?
Yes. MSG is about 12% sodium by weight, compared with about 39% for table salt. Replacing some salt with MSG can lower a dish's sodium while keeping it tasting seasoned.
How much MSG should I use?
A little goes far: about 1/4 to 1/2 tsp for a pot of soup or 500 g of food serving four. Too much tastes flat and oddly brothy, so start small.
How is MSG made?
Today it's made by fermentation, much like yogurt or vinegar. Bacteria are fed sugar from corn, sugar beets or cassava and produce glutamate, which is then purified and crystallized.