The health check How dangerous is microwave cooking really?

It is often said that microwave radiation is harmful to the body - and makes food unhealthy. But is there any truth to these claims? The microwave check.

The microwave is no longer just an appliance for reheating or defrosting. Whether leg of lamb with vegetables, gratin or cake: the microwave cooks, bakes, gratinates and grills. The fact that it does this with electromagnetic radiation still sounds scary to some. But if you pay attention to a few things, you have nothing to fear - according to current knowledge.

The first microwave came onto the market in the USA at the end of the 1940s. It was a box almost as tall as a man, weighing several hundred kilos and costing 5000 US dollars.

Today, the appliance can be found in almost three quarters of all households. It is small, no longer so expensive, and many people find it practical - but some find it dangerous.

And there are certainly points that can be criticized about using a microwave. These include the fact that it can tempt people to replace healthy, home-cooked food with frozen meals - in other words, it is relatively easy to eat relatively poorly if you have a microwave.

However, if you talk to people who are skeptical about the appliance, you are more likely to hear other criticisms than this: namely the radiation plus the destruction of nutrients. However, experts give the all-clear on both points.

In the case of tested microwaves - i.e. those bearing a seal of the VDE Association for Electrical, Electronic & Information Technologies (VDE mark) or a "GS mark" for tested safety - radiation only escapes through the window or door. The limit value for this so-called leakage radiation is five milliwatts per square centimeter (or 50 watts per square meter) at a distance of five centimeters.

However, this value is never reached by tested devices. According to measurements by the German Federal Office for Radiation Protection (BfS), only one percent of this value is reached on average.

In addition, the radiation decreases rapidly the further away you are from the device. At a distance of one meter, you only have one thirtieth to one hundredth of this value. "With technically flawless devices, there is [...] no health risk, not even for pregnant women and small children," concludes the BfS. However, if the device is visibly damaged, it should be repaired or disposed of. It is also clear that high-frequency electromagnetic radiation can cause damage, for example burns.

But what about the nutrients? As vitamins and some other nutrients are sensitive to heat, they are damaged every time they are heated. This includes heating in the microwave. On the other hand, heating to over 70 degrees Celsius also kills harmful germs.

Experts therefore recommend following the appliance manufacturer's cooking instructions exactly to ensure that food is not heated for too long or too short a time. If this is done, there are no disadvantages to be expected in terms of nutrients compared to the stove or oven, writes the Federal Center for Nutrition (BZfE), an information platform of the Ministry of Agriculture.

However, there are a few things you should bear in mind to avoid problems with the microwave: don't put anything made of metal in it, no melamine dishes (harmful substances could be released) and no closed containers (due to the risk of overpressure).

You should also stir your food more often when heating it in the microwave and leave it for a while after the "ready" beep. Because the electromagnetic waves do not pass evenly through your food, there are places that get very hot and places that stay cold.

Baby food in particular should therefore be tasted well beforehand.

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