The Microwave Myth: Nutrient Killer or Practical Helper?

“I don’t heat up your dishes in the microwave because all the nutrients are destroyed!” or:

"The microwave is really bad for your health!"

We already know them: the arguments of those who don't want to microwave our Löwenanteil of dishes. This destroys the vitamins, the food becomes unhealthier, the rays are harmful, etc.

Unfortunately, the microwave still often has a bad reputation – but why?

So that you too can warm up your Löwenanteil of dishes in the microwave with a clear conscience, we'll do away with the prejudices! Because it would be a shame not to use this practical little helper... and only because outdated opinions about the “microwave nutrient killer” prevail, right?

How does a microwave actually work?

The first microwave was invented in the 1950s. At that time, it had little in common with the space-saving, lightweight household appliances of today: it weighed a total of 350 kilograms and was 1.80 meters high. Price: a whopping $5,000.

That's why it was only used on airplanes to heat the food for the passengers. Only 20 years later did the microwave (also: microwave oven, microwave oven) make the leap into several households.

No wonder: the food heats up extremely quickly and all you have to do is press a button and close the door. Then the so-called magnetron in the microwave does all the work.

As if by itself, it ensures that the food heats up by generating high-energy waves and thus an alternating electric field. This field changes its orientation about 5 billion times per second (!): The plus pole becomes the minus pole and vice versa.

The result: the water molecules in the food oscillate.

microwave water molecules

Water molecules (H2O) are polar, i.e. they have a negatively (O) and a positively charged side (H). Therefore they try (similar to a compass needle) to align themselves with the electric field. However, since this is constantly changing its direction, the water molecules do not stop vibrating and instead try to keep up. So they collide with neighboring molecules, which also move, then bump into others etc. This creates frictional heat at the molecular level and voila: our food gets warm.

Don't worry: That's it for physics, chemistry and the like! Now that we know how a microwave works, let's get down to business.

How Healthy is Microwave Food?

Are you still skeptical? Then we can reassure you: food from the microwave is healthy. It is neither "radiated" nor nutrient deficient, nor has it been altered by the magnetron.

In order to dispel the prejudices that still exist, we have selected 2 microwave myths that we will deal with in more detail:

Myth 1: Microwave radiation is harmful

Microwave radiation is not harmful to our food. After all, they only ensure that the water molecules they contain move. Put simply, they are responsible for transporting energy.

Also, since microwaves are non-ionizing radiation, they are not found in the food once it has been heated. It would be different with radioactive radiation, for example.

There is no danger from the rays for us either. However, if we were directly exposed to them, the radiation could also cause the hydrogen molecules that are in our body to vibrate. So they would be potentially cell-damaging.

microwave radiation

On the one hand, however, this is prevented by the protective mechanism, which ensures that the device switches off as soon as the door is opened.

On the other hand, the metal grids that can be found in every microwave protect us: They shield us from the radiation so effectively that, according to the Federal Office for Radiation Protection , only 5-10% of the microwave intensity is present at a distance of 30 cm. This is less than a mobile phone would cause at a distance of 5 cm and is also within the specified limit value for leakage radiation: The radiation that escapes to the outside may only be 5 milliwatts per square centimeter - at a distance of 5 cm from the device.

Of course, that shouldn't be a free pass for just staying in front of the microwave (especially children should be kept away from radiation), since exposure to high-frequency fields should be avoided in general. Nevertheless: Intact devices are shielded so well that they do not harm us.

So if, once again, we can't wait to finally enjoy our Löwenanteil dish, we could even position ourselves the 3 minutes in front of the microwave. That would not pose a health risk to us. And maybe gives us the feeling that the food will be ready faster...

Myth 2: The microwave destroys nutrients

Another myth that still persists - wrongly so! It has now been proven that the radiation does not alter nutrients. This is done solely, if at all, by microwave heat. And that heat is no different than that given off by the stove or oven.

microwave nutrients

How the microwave (or stovetop, oven, steamer...) changes the nutrients depends on the food. For example, there are fat-soluble vitamins (e.g., vitamins A, D, and E) that require both heat and fat to be utilized by the body.

On the other hand, vitamin C or B1, both of which are sensitive to heat, should be prepared quickly and gently so that they are not destroyed. This is also the reason why you shouldn’t use boiling water for the popular “hot lemon” drink, but rather warm water. Otherwise, a large part of the vitamin C would be lost.

The food itself is therefore decisive for the nutrient content after preparation. For example, there are foods that lose some of their nutrients in the microwave, such as garlic : cancer-preventing antioxidants are already destroyed after one minute in the microwave, in the oven only after 45 minutes. (Tip: To counteract this, the garlic can be left for about 10 minutes before cooking in the microwave. This will preserve the antioxidants).

Broccoli also loses some of its vitamin C and chlorophyll when it is microwaved. But (!) that's exactly what happens when you fry or boil it. The only gentle method of preparation is steaming.

Microwave broccoli

On the other hand, according to one study , some celery loses about 14% of its antioxidant power when cooked, while microwaving it actually increases it. Peas also lose more radical scavengers when cooked than in the microwave.

Nonetheless, the differences between microwave and alternative cooking methods are so small that even a 2009 study found that "there are no significant nutritional differences between foods cooked using conventional and microwave cooking methods."

As a rule of thumb, you can remember that most nutrients are lost during cooking. Nutritionist Niko Rittenau therefore recommends using the cooking water from vegetables in sauces etc. in order not to lose the nutrients (vegan cliché goodbye! The cookbook, p. 15).

In addition, very rapid thawing can destroy cell walls. Here the microwave is even more practical than heating it up in a pot, as it heats on a molecular level - i.e. gently from the inside and not just from the outside.

Conclusion: The myth that the nutrients are damaged in the microwave is wrong. Yes, they can be changed. But the same can also be done on the stovetop or in the oven.

Few foods can therefore be less health-promoting both in the microwave and with other cooking methods. However, nutrients remain in their form - albeit in rare cases in smaller quantities. Preparation in the microwave is in no way harmful to health.

So isn't the microwave dangerous at all?

If you have a working microwave: no. The rays stay where they're supposed to be in the microwave cavity, and the nutritional content of the meal doesn't change much either.

Nevertheless, there are a few things that should be considered, first and foremost choosing the right container: Ceramic and glass are usually microwave-safe. Are you unsure? Then look for a note from the manufacturer. A symbol of three waves in a rectangle means that you can put the jar in the microwave.
microwave vessels

You could also put our Löwenanteil glasses in the microwave, for example. Important: remove the cover in front of it. You should also be careful not to overflow while heating your dish. That's why we recommend putting the dish on a plate so that everything heats up evenly, nothing overflows and you can enjoy the full taste.

In general, you should make sure that your vessels do not have any cracks. Water can collect in it, the water molecules of which can be heated and cause the vessel to burst. So if at some point you not only have warm food, but also a warm vessel, it is better to examine the latter for cracks.

Plastic should also not be put in the microwave unless the manufacturer specifically states so. There is also a danger with aluminum containers, metal cutlery or wood, which in the worst case can burn or melt.

Which foods do not belong in the microwave?

Have you ever taken something out of the microwave and noticed that it was still cold in some places? This can happen (therefore always stir in between!) and even has a name: hot spots & cold spots.

From time to time the food is not heated evenly. Most of the time, the differences are so small that we don't even notice that some areas aren't quite as warm. The disadvantage: Potential bacteria and salmonella cannot be killed in this way. Fish, for example, should not be prepared in the microwave - and if so, then with a lower wattage and longer cooking time.

microwave fish

Even raw meat has no place in the microwave. Controlling the temperature is much more difficult than in a pan, for example, and there is too great a risk that it will not be sufficiently heated after preparation.

Be careful with eggs too: they will explode if you put them in the microwave. The water molecules oscillate back and forth, eventually causing the shell to burst. And no one wants to get rid of this mess...

Which meals you don't need to worry about? With our ready meals! They are already pre-cooked, in organic quality and only need to be heated. Salmonella and Co.? none.


As you can see, there's no reason to continue demonizing the microwave. Its rays neither harm us nor destroy the nutrients in our food. We have summarized everything important for you here at a glance:

  • Microwaves set water molecules in food in motion → frictional heat that warms the dish.
  • The composition of your dish is not changed in the microwave → Microwaves are non-ionizing and therefore not able to change your food at all.
  • Cooking in the microwave is no different than cooking on the stovetop or in the oven.
    • Reason: It depends on the food and its properties, whether it is fat-soluble or water-soluble. Depending on the device, the nutrient content may be slightly different after preparation.
  • Be careful when choosing dishes. Metal has just as little place in the microwave as plastic.

Still deciding where to heat up your next Löwenanteil dish? So much can be revealed: the microwave does not destroy any nutrients and does not change the great taste of our chili, bean stew, curry...

Enjoy it (without a guilty conscience!) - whether from the microwave or from the stove.