Social Media Is Wrong About Microwaves

Microwaves are convenient. Too convenient, perhaps. So convenient that some of us are suspicious of them. When these common appliances were new on the kitchen scene, there were objections to the supposedly unnatural way they heat food — remember that urban legend about the girl who boiled her brain while trying to dry her hair because microwaves “cook from the inside out”?

Over the decades, microwave myths have mostly faded away — or so I thought. But because nothing is too crazy to believe these days, some of them are making a comeback. A social media influencer recently posted a video in which he microwaved some food for his child, and was met with comments saying that microwaving “takes all the nutrition out of the food!”

It’s not just that one guy’s followers. Microwave misinformation is running rampant on TikTok, among other places. Here’s a clip calling microwaved food “the best way to kill yourself, really really fast.”

So what’s the deal? Are microwaves unsafe? Is food cooked in them less healthy than food cooked via other methods?

Does microwaving food destroy nutrients?

No. Or at least, it doesn’t do anything to the nutrients that cooking by another means wouldn’t do.

Microwaves don’t cook food by magic. They heat up water molecules, and then the hot or warm water helps to warm the rest of the food. Think of it like putting food in a water bath, like when you defrost a sauce packet by popping it into a mug of hot water.

What happens to the nutrients during this process? Well, different means of cooking can have different effects on nutrients, that’s true. Boiling food can cause some nutrients to leach out into the water, but that’s not an issue here, because the water that heats up is part of the food itself. Some vitamins do start to break down after a long time in high heat, but it’s hard to destroy them entirely. Actually, since microwave cooking happens so quickly, it is considered to be one of the best methods for preserving the nutrients in food.

There is some evidence that microwaving can reduce the amount of vitamin C in food by 20% to 30%, according to Healthline, but the same article also notes that boiling can reduce vitamin C by 50%, and that stir frying can “significantly reduce” vitamin C content in vegetables. Every cooking method has its tradeoffs, but microwaving isn’t notably worse than others.

Do microwave ovens expose us to radiation?

Technically yes, but not in the way you think.

When we worry about radiation, we’re thinking of ionizing radiation, the kind that comes from X-rays and nuclear bombs. People and objects that are exposed to ionizing radiation can (in some cases) become radioactive themselves, which is a big part of why this type of radiation is so dangerous.

But microwaves are non-ionizing radiation. Other types of non-ionizing radiation include visible light, ultraviolet light, and the infrared waves from a heat lamp. They also include radio waves in all their forms. To name a few examples: the waves that come from radio towers and are picked up by your car radio, the ones that are transmitted by one walkie-talkie in a set and are picked up by the other, and the ones that come from your wi-fi hotspot and that are picked up by your phone or computer. (Microwaves operate on a frequency that’s very similar to wi-fi, by the way; that’s why a microwave with damaged shielding can cause hiccups in your wi-fi connection.)

So, no, microwaves don’t produce “radiation” in the scary (ionizing) sense, and they do not make your food radioactive. No health hazards here.

Why shouldn’t you heat baby formula in a microwave?

If microwaves are so safe, why are we sometimes told not to heat baby formula or baby food in a microwave? It’s not because the microwave damages the food, but because it can heat the food unevenly. If there are hot spots in the bottle or the bowl of food, and it’s not fully mixed before giving to the baby, the baby could get a mouthful of too-hot formula. If you’ve ever microwaved food for yourself, you’re likely familiar with this phenomenon. Better to warm the bottle in a bath of hot water, the better to heat it evenly.