Is glutamate unhealthy?

What is glutamate?

Most people probably know glutamate simply as a flavour enhancer in Aromat. But glutamate is more than just an industrial additive – we can't live without it. As the salt of glutamic acid, it's an amino acid and therefore a fundamental building block of proteins.

Which types of glutamate exist?

Broadly speaking, there are 3 forms:

1. The body's own glutamate: The body produces its own glutamate by breaking down proteins obtained through food. It's found in almost all body cells and performs vital functions.
2. Naturally occurring glutamate in foods: Glutamate is found naturally in many foods for the simple reason that all plants, animals and fungi contain glutamic acid. Fermented products in particular contain high levels, as glutamic acid is released during the maturation process.
3. Industrially produced glutamate: Artificial glutamate is added to foods as a flavour enhancer to provide a savoury taste. It's also produced through fermentation and is most commonly used as monosodium glutamate, known as E621 or MSG. On packaging, it's often hidden behind terms such as flavouring, seasoning, yeast extract or fermented wheat.

What does glutamate do in the body?

Glutamate is active throughout the body. In cells, it supports energy production and serves as a building block for other amino acids. In the gut, it helps maintain the stability of the intestinal lining and supports the immune system.

Glutamate in the brain

In the brain, glutamate has a particularly important role: It's the primary messenger between nerve cells. Without it, essential processes such as learning, memory and movement wouldn't function. The brain produces its own glutamate for this purpose. Abnormally high or low levels of glutamate in the brain can disrupt these processes. The glutamate we consume in food barely reaches the brain and therefore has no real impact on it. Glutamate obtained from food is mainly metabolised in the gut and liver.

Glutamate in foods

Glutamate is widespread, both in natural foods and as an added flavour enhancer. That means we consume it every day, even as part of a fully balanced diet.

Foods that contain glutamate

Natural sources of glutamate

• Tomatoes: Ripe tomatoes in particular contain high amounts of natural glutamate.
• Cheese: Parmesan and other mature cheeses are rich in natural glutamate.
• Mushrooms: Shiitake mushrooms in particular contain a lot of natural glutamate.
• Meat / fish: In general, protein-rich foods contain a lot of glutamate as it’s a component of most proteins.
• Soy sauce: Due to the fermentation processes, soya sauce is rich in natural glutamate.

Foods that contain added glutamate

• Ready-made soups and stock cubes: Glutamate is often added to enhance the flavour.
• Spice mixes and spicy sauces: Many commercially available spice mixes contain glutamate.
• Fast food and snacks: Fast food meals and snacks such as crisps are often flavoured with glutamate.
• Frozen meals: Many frozen meals contain glutamate to enhance their flavour.
• Instant noodles: A classic product that often contains glutamate.

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

Is glutamate unhealthy?

According to current scientific evidence, glutamate is safe when consumed in normal amounts. Even so, it's the industrial use of glutamate that often attracts criticism. The following side effects are often attributed to glutamate:

Chinese restaurant syndrome

Since the 1970s, many diners have reported symptoms such as headaches, nausea and numbness after eating glutamate-rich dishes, particularly in Asian restaurants. Today, we know that this "syndrome" isn't scientifically substantiated and is thought to have arisen from a mix of misinformation and cultural bias. The occasional claim that it occurs only in cases of vitamin B6 deficiency isn't supported by enough scientific evidence to be valid.

Toxic effect

Because of its role in the brain, glutamate is said to have a neurotoxic effect that could lead to conditions such as Alzheimer's or Parkinson's. However, these concerns stem from animal studies in which extremely high doses were injected directly into the bloodstream. There's no evidence of neurotoxic effects in humans at normal levels of dietary intake.

Increased appetite

Glutamate can make food more palatable. It's therefore been suggested that it stimulates appetite and contributes to overeating and obesity. While this sounds plausible, a causal link hasn't been scientifically established.

Glutamate intolerance

In rare cases, individuals report symptoms such as pain, flushing or itching after consuming very high amounts of glutamate. However, this is a very uncommon phenomenon and its effects have never been replicated in scientific studies to date.

Normal consumption is safe

Overall, there's no solid scientific evidence supporting the most common concerns. Expert bodies consider glutamate safe when consumed in normal amounts. These include the German Federal Institute for Risk Assessment, which regards an intake of up to 30mg per kilogram of body weight as safe – that's around 2,300mg per day for an average adult.

From a scientific perspective: Is glutamate harmful to our health?

Based on current evidence, glutamate isn't harmful to our health. Neither double-blind studies nor the overall body of research provides convincing proof of adverse effects. An allergic reaction to glutamate has also not been clearly demonstrated.

So the bottom line is: If you eat a balanced diet and consume glutamate in moderation, you shouldn't experience any health effects.