A microwave oven for recycling
A meme on Facebook lists "4 reasons to throw out your microwave today". Image by Julian Smith/AAP IMAGES

Microwave meme cooks up cancer food fears

Zathia Bazeer August 31, 2022

Microwaved foods lead to a higher percentage of cancerous cells in the bloodstream.


False. There is no evidence that microwaved foods cause cancer or increase cancerous cells.

A Facebook post claims microwaved foods can increase cancerous cells in the bloodstream.

It is one of several claims made in the post which was shared in the Facebook group We Say NO to 5G in Australia on August 18.

Number three of the meme’s “4 reasons to throw out your microwave today” is “microwaved foods lead to a higher percentage of cancerous cells in the bloodstream”.

But the claim is false with experts telling AAP FactCheck that microwave ovens produce non-ionising radiation, which does not cause cancer. There’s no scientific evidence that microwaved food is unsafe or that the radiation from microwaves increases  cancerous cells in the bloodstream.

In a fact sheet on microwave ovens and health, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) states there “is no established evidence that microwave ovens cause any health effects when used according to the manufacturer’s instructions and maintained in good working order.”

ARPANSA says microwaves generated in microwave ovens “cease to exist once the electrical power is turned off. They do not remain in the food when the power is turned off. They do not make the food or the oven radioactive”.

A server dishes a plate of paella
 The nutritional content of some foods may be altered by microwave cooking, compared to conventional. 

“There is some evidence that nutritional content of some foods may be altered differently by cooking in a microwave oven, compared to conventional cooking, but there is no indication of detrimental health issues associated with microwaved food,” it says.

ARPANSA’s findings are echoed by the Cancer Council.

Dr Ian Musgrave, a molecular pharmacologist and toxicologist at the University of Adelaide, said there is no evidence at all regarding microwaved foods causing cancer.

“Eating microwaved foods will not cause cells to become cancerous and enter your bloodstream. Unless you have cancer, there are no cancerous cells in the bloodstream,” Dr Musgrave told AAP FactCheck via email.

“Microwaved foods can’t increase something that is not there (if you do have cancer, microwaved food will not make it worse).”

Professor Ian Oliver, oncologist and cancer researcher at the University of Adelaide, said there is a difference between ionising and non-ionising radiation.

“Ionising radiation like that produced by a radiotherapy machine or by a nuclear explosion has sufficient energy to remove electrons from molecules and break DNA which can kill cells and disrupt cells and cause cancer,” he said.

“Non-ionising radiation is not strong enough to remove electrons. Microwave ovens produce non-ionising radiation. It can move molecules and produce heat and it is the vibration of water molecules which in a microwave heats the food, but because it is not ionising it does not cause cancer and it does not alter the chemical structure of food. Ingesting the food will not cause cancer.”

Julian Cox, scientific director of the Food Safety Information Council, confirmed that microwaved foods are safe when ingested.

“I think people see ‘radiation’ and assume it’s harmful. Microwaves are of relatively low energy, and are non-ionising, so changes to biological matter, including cells, does not happen,” Dr Cox said.

Experts say you do not need to fear your microwave.
 Experts say you do not need to fear your microwave. 

“Even research on the use of ionising radiation, such as gamma irradiation, in the treatment of foods, shows no evidence of unique radiochemicals. We know ionising radiation, applied directly to the body (e.g. X-rays) can be potentially harmful, but research shows that such radiation used on foods does not induce changes that could be harmful upon ingestion.”

Similar claims have been debunked widely by other outlets – examples are here, here, here and here.

The Verdict

The claim that microwaved food leads to a higher percentage of cancerous cells in the bloodstream is false. Microwaves produce non-ionising radiation which cannot change cells or change chemical structure in food. 

Any microwaves generated in the heating process cease to exist once the power is turned off and do not remain in the food.

False ÔÇô The claim is inaccurate.

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