What is glutamate?
Most people probably know glutamate simply as a flavour enhancer in Aromat. But glutamate is much more than just an industrial additive – we can't live without it. Glutamate, the salts of glutamic acid, are non-essential amino acids and, as such, are protein building blocks. These are produced by the human body itself and act as neurotransmitters in the brain.
As a neurotransmitter, glutamate transmits information between nerve cells and thus performs an important function in the body. Information is passed from one cell to the next, for example when we're learning or when we move.
Discovered in Japan: origin of glutamate
Industry uses the salts of L-glutamic acid. The most common industrial additive is monosodium glutamate, also known as E621, that spices up the flavours of pizza, soup and crisps. In 1908, Japanese professor Kikunae Ikeda succeeded in extracting precisely this monosodium glutamate from Kombu seaweed. This made him the discoverer of the fifth flavour umami and the flavour-enhancing property of glutamate. Neither sweet, salty, sour or bitter, umami is described as fleshy, spicy or pleasantly tasty.
Today, glutamate is industrially produced by fermentation and can be found on the list of food additives under the E-substance numbers E620 to E625. The designation isn't always clear to the consumer, because producers often use synonyms that sound more innocent than the E-substance numbers, such as seasoning, aroma, yeast extract or fermented wheat.
Side effects of glutamate
It is primarily the industrial use of glutamate that comes under criticism.
- China restaurant syndrome: In the 1970's, the first health concerns were raised in connection with what was known as the China Restaurant Syndrome. After eating food containing glutamate in mainly Asian restaurants, many guests experienced symptoms such as headaches, nausea and numbness.
- Toxic effect: Glutamate is said to have a neurotoxic effect, which can lead to diseases such as Alzheimer’s and Parkinson's disease.
- Increased appetite: Glutamate plays a role in regulating appetite in the brain. It is said to increase appetite and thus to be partly responsible for obesity.
Glutamate in foods
Some foods naturally contain glutamate. We therefore consume approx. 10-20mg glutamate per day as part of a balanced diet.
Glutamate content in mg per 100g food:
- Soy sauce: 1,260mg
- Parmesan: 1,200mg
- Anchovies: 630mg
- Smoked ham: 340mg
- Peas: 200mg
- Tomatoes: 140mg
- Sweetcorn: 110mg
- Potatoes: 30-100mg
Harmful or harmless? What the science says
Neither double-blind experiments nor general data sufficiently support these allegations. Decidedly more extensive studies would be necessary. National experts therefore agree that glutamate in normal amounts doesn't pose a health risk in a balanced diet. It has also not been confirmed that glutamate can trigger allergic reactions. Nevertheless, certain people are glutamate-intolerant.
Therefore: eating a balanced diet and consuming glutamate in moderation – especially in ready-made meals - is certainly not harmful. But those who are intolerant should avoid it completely.