Monosodium glutamate is bad for dogs

Flavor enhancer: is glutamate even healthy?

Anyone who prepares a sachet of soup, cooks ravioli out of a can or throws a handful of flips will in most cases consume sodium glutamate. Because glutamate is an additive in numerous foods to make them more palatable. But the substance has been controversial for decades. Obesity, Alzheimer's, Parkinson's and diabetes are just some of the diseases that are discussed in connection with glutamate. Right? Or is the concern exaggerated? And why do many products taste better than others with glutamate? Read the most pressing questions and answers here:

What is glutamate anyway?

Glutamate is an additive that is used in foods as a flavor enhancer. Glutamate is not a man-made artificial product: Glutamates occur in nature, they are salts of the natural amino acid L-glutamic acid. Vegetable protein contains up to 20 percent glutamic acid, and animal protein - i.e. eggs, milk or meat - up to 40 percent. So every protein-containing food also provides glutamic acid. A lot of it can be found in eggs, fish, soy, yeast, tomatoes or cheese. Roquefort cheese, for example, contains 1280, Parmesan 1200 and soy sauce 1090 milligrams per 100 grams.Especially during the fermentation of food - among many other substances - glutamate is also released. The salts are even formed during the production of sauerkraut or beer, albeit in smaller quantities. Paul Breslin, a taste researcher at Rutgers University in New Jersey, therefore suspects that the human predilection for foods containing glutamate emerged together with a diet that relied on fermented and therefore longer-lasting foods.

Glutamic acid docks with the taste receptors in the human tongue and thus triggers the so-called »umami« taste sensation: It is perceived as spicy or meat-like and described as hearty, earthy or refined. And that since 1908: Back then, a Japanese chemist named Kikunae Ikeda came up with the idea of ​​the fifth sense of taste »umami« when he was looking for the spicy aroma of Kombu Dashi, an algae broth. He found out that glutamate was not only found in the meat broth that Justus Liebig was successfully selling at the time, but also in the traditionally brewed Japanese algae: Both are umami, which in Japanese means tasty. It was not until the discovery of the umami receptors on the tongue about 20 years ago that Ikenada's theory that umami is a flavor of its own was finally substantiated.

Which foods contain glutamate?

Manufacturers of ready-made foods have been mixing glutamate into their products as a flavor enhancer for more than 100 years. The industry mostly produces the salts from molasses with the help of genetically modified bacteria. Consumers recognize the substances under the E numbers E 620 to E 625. Glutamates are used as flavor enhancers in ready meals, bag soups and sauces, canned meat, fish and vegetables as well as in snacks such as crisps, in condiments and as a substitute for table salt. Glutamic acid and its salts are allowed in almost all food categories with a maximum of 10 grams of additive per kilogram. The best-known glutamate is the sodium salt of glutamic acid: monosodium glutamate (E 621).

What does it do?

The body makes glutamate itself, about 50 grams per day. It is found in muscles, brain, kidneys, and liver. This is called endogenous glutamate - in contrast to the exogenous glutamate that humans get through food. Chemically, both are identical. A Central European consumes an average of 0.3 to 0.5 grams of glutamate per day from ready-made meals, in Asia it is even 1.5 grams. Europeans consume around one gram of free glutamate and 20 grams of protein-bound glutamate from natural foods. Only the free glutamate has a spicy taste. In the body, glutamate is first broken down in the small intestine and is used to supply energy to intestinal cells or as a building block for important molecules in the intestine. Only a small part is then found in the blood. Glutamate doesn't just bind to taste cells in the tongue either. Umami receptors have been found both in the intestine and on sperm.

Endogenous glutamate also has many roles. It is about the most common decaying neurotransmitter in the central nervous system. It enables the transmission of signals between the cells and thus, among other things, the memory functions. However, too much glutamate in the brain also leads to the death of brain cells. Diseases such as Alzheimer's, Huntington's disease, Parkinson's or multiple sclerosis are associated with increased glutamate concentrations in the brain.

Is it harmful to health - especially for babies?

Skepticism about the additive arose as early as 1968 after the US doctor Robert Ho Man Kwok published an article in the New England Journal of Medicine. Under the title "Chinese-Restaurant Syndrome" he reported about himself: After visiting a Chinese restaurant he was always plagued by deafness, weakness and a racing heart. His medical colleagues then diagnosed a soy sauce allergy. He countered that he also used plenty of soy sauce on the stove at home, but tolerated it.