“Microwaves make food radioactive” Microwaves are high-frequency radio waves (radiofrequency fields) and, like visible radiation (light), are part of the electromagnetic spectrum, explains the World Health Organisation. They are not radioactive, so they cannot make food radioactive.

“Radiation in microwaves causes cancer” When people talk about radiation, they mean ionising radiation, which is made of high-energy waves: gamma rays and x-rays are examples. Through a very complicated process, the energy can enter cells and chemically change the way the cell works, a process called ionisation. Ionising rays can remove an electron from an atom or molecule (ionise), which can damage DNA inside cells, giving rise to cancer. Microwaves use non-ionising radiation that lacks sufficient energy to damage DNA, so they can’t cause cancer.

“Microwaves leak radiation” Samples of all microwaves are tested for leakage before being released for sale. Microwave doors are designed with at least two features to ensure power is cut off the moment the door is opened, says the CSIRO. An oven in good condition and used correctly is safe. It is possible microwaves may leak from around the edges of a poorly fitting, damaged, or food-encrusted door. However, it’s extremely rare for microwave oven leakage levels to exceed the NHMRC’s recommended levels.

“Microwaves destroy nutrients in food” Any changes they make to food are the same as created by any other cooking method. Most reports indicate that food cooked in microwaves is at least as nutritious as comparable food cooked by conventional methods, the CSIRO notes.

“Chemicals leach into food from plastic” It’s important to use only microwave-safe containers to stop chemicals migrating into food. Never use containers from chilled foods like yoghurt, as their low-melt temperatures can cause migration of contaminants. If using cling film, ensure it’s not in direct contact with food.

“Microwaves cause cataracts” Peer-reviewed scientific animal studies investigating effects of microwave exposure on the eye have found it takes a continuous exposure of around one hour at 80 to 100 milliwatts/square centimetre for a cataract to form. Translation: Even if you sat with your eye a couple of centimetres from the oven for an hour, simply not enough energy is available to heat your eye and damage it.

“Microwaving water alters its DNA and kills plants” This comes from a child’s (non-double-blind) school science experiment that purportedly proved a plant was destroyed after a week of being watered with microwaved water, while an identical plant given tap water survived. The lengthy Snopes investigation of this claim makes fascinating reading:

The no-nos

There are some “cons” related to microwaving, but none of them involve radiation.
* Microwaves are not suited to all cooking, but this applies to any medium. You’ll never get a crisp flaky croissant by warming it in the microwave, but nor will you if you put it in the steamer.
* Food cooked in a microwave does not heat uniformly. This can risk causing burns, but also allow harmful micro-organisms to survive in parts of the food. For safety, divide large quantities of food into smaller portions when reheating. Burns can also occur from steam emitted from closed packages, such as microwavable popcorn bags.
* Finally, read the manual carefully, and follow instructions scrupulously. Keep the oven clean and monitor it so it remains in good condition.

Dr Sandi Rogers, N.Dd, ED.D., is a life member of the Australian Traditional Medicine Society (ATMS).