Microwaves don’t make food ‘highly toxic’

29 June 2022
What was claimed

Microwave ovens turn food nutrients into toxins.

Our verdict

This is not true. Microwaves do not make food toxic.

A video on Instagram, which is also being shared on Facebook, claims that cooking food in microwave ovens is “the best way to kill yourself, really, really fast”.

The man in the video says: “The microwave is basically destroying every food value that’s in the food and turning it into a toxin. So everything out of the microwave is highly toxic, and the food value is completely zero. So it doesn’t really matter if you have a bowl of vegetable soup that you warm up in the microwave oven or if you eat cardboard. It makes no difference, because the food value is not there any more, and it also becomes toxic.”

This is nonsense.

A spokesperson from the Food Standards Agency told Full Fact: "We believe that the comments made in the video have no scientific credibility from a toxicological point of view."

Do microwaves destroy nutrients?

While it’s true that microwaving food may reduce its nutrient content, the same is true for all forms of cooking, as heat itself can break down nutrients.

Writing in the Harvard Health Letter, Dr Anthony L. Komaroff, a professor of medicine at Harvard Medical School, says: “Cooking damages the chemical structure of the nutrient, to some degree. However, there are plenty of nutrients left. And cooking kills many microbes that might have contaminated the food—and might have caused health problems.”

Indeed Dr Komaroff goes on to say that “microwave cooking is actually one of the least likely forms of cooking to damage nutrients”, because of the short cooking time that may be involved.

Do microwaves make food toxic?

Microwaves do not make food toxic.

According to the US Food and Drug Administration (FDA): “Microwaves cause water molecules in food to vibrate, producing heat that cooks the food. That's why foods that are high in water content, like fresh vegetables, can be cooked more quickly than other foods. The microwave energy is changed to heat as it is absorbed by food, and does not make food ‘radioactive’ or ‘contaminated’.”

There is some evidence that chemicals from some plastic containers may escape into food that is stored or heated in them. The science of this, and any possible effects on human health, is still uncertain.

The consumer advice magazine Which? says: “It's a good idea to stick to containers that are both BPA and phthalate-free, and clearly marked as safe for microwave use.”

It may also be best to avoid using damaged plastic containers, or to use containers made of glass or ceramics instead.

The most common injuries associated with microwaves are burns, according to the FDA.

Image courtesy of Lissete Laverde

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