Are Microwaves Bad for You or Your Food?

Since microwave ovens became affordable in the 60s, they’ve turned into a key fixture in most kitchens, celebrated as a quick and convenient way to cook.

Despite their ubiquity, many still wonder: Is microwaving food bad for you?

Some “experts” suggest so, arguing microwaves make food “radioactive” and emit toxic radiation, which raises cancer risk. 

Others believe microwaves “kill” food of its nutrients, increasing your risk of nutrient deficiencies. And still others say there isn’t enough research on microwaves, so we should all play it safe and avoid them.

Not everyone agrees with these claims, though. In fact, many dismiss them as baseless, viewing microwaves as a triumph of science we shouldn’t worry about.

Who’s right?

In this article, we’re going to dig into the research to answer some of your most pressing questions, including: 

• Are microwaves dangerous?
• How do microwaves work?
• Is it dangerous to microwave plastic?
• Does microwaving kill nutrients?
• And more. 

Table of Contents

• Why Do People Think Microwaving Food Is Dangerous?
• Microwave Myth #1:Microwaves Release Harmful Radiation and Make Your Food Radioactive
• Microwaves and Radiation
• Do Microwaves Emit Radiation?
• Microwave Myth #2: “Microwaving Lowers the Nutrient Content of Your Food”
• Does Microwaving “Kill” Nutrients?
• Microwave Myth #3: “Microwaving Plastic Containers Releases Toxic Chemicals”
• Does Microwaving Plastic Release Toxins?
• Microwave Myth #4: Microwaving “Kills” Food
• Does Microwaving “Kill” Food?

Why Do People Think Microwaving Food Is Dangerous?

There are four reasons people say that microwaving food is dangerous:

1. Microwaves make your food radioactive and release harmful radiation, which raises your risk of cancer.
2. Microwaves destroy the nutrients in your food, increasing your risk of nutrient deficiencies.
3. Microwaves cause plastic containers to release harmful chemicals into your food.
4. Microwaves “kill” the beneficial properties of “live” food.

These concerns sound plausible. So, is microwaving food bad for you?

Let’s unpack each idea to find out.

Microwave Myth #1:Microwaves Release Harmful Radiation and Make Your Food Radioactive

When you think of the word “radiation,” you probably think of the effects of a nuclear bomb or a power plant disaster: awful burns, cancer, and a slow, painful death.

It makes sense you’d be worried about using the same technology to warm your food.

Therein lies the first problem in the anti-microwave argument, though—it’s not the same technology.

To understand why the radiation from microwaves isn’t dangerous, you first have to understand how radiation and microwaves work.

Microwaves and Radiation

“Radiation” is a broad term that includes any kind of energy that falls on the electromagnetic spectrum. 

Just about everything around you emits some level of radiation, including the light from bulbs, the ground, and even your device’s screen.

Some types of radiation are healthy (you need sunlight to produce vitamin D), some are benign (cell phones), and some are dangerous (nuclear bombs). 

The different types of radiation are categorized based on the size and frequency of their wavelengths. 

Large, low-frequency wavelengths tend to be the safest, like the kind emitted from radios (radio waves). On the other end of the spectrum, you have small, high-frequency wavelengths, which are dangerous.

As you can see in this chart, some wavelengths are bigger than buildings, and others are the size of atoms.

You can further divide these different types of wavelengths into two categories: non-ionizing radiation and ionizing radiation.

Here’s where most kinds of radiation fall on that spectrum:

Ionizing radiation is strong enough that it can destroy atoms, including the ones that make up your body.

Non-ionizing radiation is only strong enough to “excite” atoms—making them wiggle at a higher frequency.

Microwave ovens use, obviously, a kind of radiation called “microwaves,” which are also emitted from cellphone towers and T.V. satellites. 

So, why don’t cell towers and satellites warm things like an oven?

Well, there are two other variables that control the intensity and effects of radiation: 

1. Proximity
2. Power

The farther you are from a source of radiation, the less reaches your body. Likewise, the weaker the source of radiation, the less reaches your body.

Radiation of every type becomes weaker the farther it travels (due to the inverse-square law). 

For example, although you’d have an elevated risk of cancer for the rest of your life, you could be several miles away from a nuclear blast and remain unscathed, depending on the size of the bomb. 

Similarly, if the source of radiation is weak—as it is with a microwave—you can be standing right next to the machine without suffering any negative effects. This is also due to the protective radiation shield built into all microwaves.   

In fact, this safety barrier is also essential to the proper functioning of a microwave oven.

If the radiation waves inside a microwave oven are allowed to travel at random, they fizzle out too quickly to heat anything.

Microwave ovens work by trapping the microwaves inside a smaller area, so your food absorbs them before they can dissipate.

Microwaves have another property that makes them perfectly suited for heating food: They only heat certain kinds of molecules, water being the main one. This is why certain kinds of glass don’t warm up in the microwave—most of the molecules aren’t affected by microwaves.

When you microwave food, the radiation is quickly absorbed by the water molecules in food, which begin to vibrate and rub against one another. The friction between the molecules generates heat, which is what warms your food.

Now, for something to be “radioactive” it needs to emit ionizing radiation, which microwaves don’t. Microwaving food also doesn’t impart any radiation into food, so it’s impossible for a microwave to make your food “radioactive.”

The wavelengths emitted from a microwave are powerful enough to boil water, but not enough to irradiate your food or damage DNA.

Do Microwaves Emit Radiation?

What if some of that radiation were to leak out? Couldn’t that still hurt you?

No, not if the microwave is functioning properly.

This has to do with the size of the wavelengths created by microwave ovens. The wavelengths generated by microwave ovens are about 5 inches wide, which is too big to pass through the metal safety shield built into all microwaves.

Even if you were able to run your microwave with the door open, the wavelengths would be too dispersed to cause any real damage. A good example of this is the man who invented the microwave oven, Percy Spencer, who first thought of the idea when a radar device he was working on melted the candy bar in his pocket without hurting him.

That’s all well and good, but what does the research show?

Well, there aren’t any controlled studies on this for two reasons:

1. You’d have to expose people to large amounts of microwaves for years, in a controlled setting, which would be extremely hard to do.
2. There’s little reason to believe microwaves are harmful based on what we know about physics.

Several observational studies have tried to measure the relationship between microwaves and breast cancer, and the results have been all over the place. Some studies show a very small correlation between breast cancer and microwave exposure and others don’t. 

In any case, none of these studies can show that microwaves caused an increase in cancer rates, since observational studies can’t prove causation.

Long story short, microwaves are about as “dangerous” as listening to the radio.

Microwave Myth #2: “Microwaving Lowers the Nutrient Content of Your Food”

You may have heard that microwaves destroy many of the vitamins and minerals in food, making them less nutritious. 

Typically, you’re told that the radiation from microwaves is uniquely destructive, and that it removes far more nutrients than other kinds of cooking.

Does Microwaving “Kill” Nutrients?

Microwaves can slightly reduce the nutrient content of some foods, but not enough to make a significant difference in your health, vitality, or longevity.

As far as cooking methods go, microwaving is actually one of the best methods for preserving the nutrients in food.

All forms of cooking reduce the nutrient content of food. When you heat food, some of the water evaporates, taking a portion of the nutrients with it.

If you want to retain the nutrients in your food, then you want to cook them quickly and with as little water as needed, which is exactly what microwaving does.

In some cases, microwaving actually makes foods more nutritious because they’re easier to digest and absorb.

Microwave Myth #3: “Microwaving Plastic Containers Releases Toxic Chemicals”

According to many, plastic containers of all kinds are toxic. They leach harmful chemicals into your food that cause a number of health problems.

There’s a kernel of truth here, but most of the fear is unfounded.

All plastic containers are made from a smorgasbord of chemicals, and some of these chemicals can transfer into your food.

The question is whether or not these chemicals are released in large enough amounts to harm your body.

The two main chemicals we’re talking about are:

• Bisphenol A (BPA) 
• Phthalates

At high doses, it’s possible that both can mimic the effects of estrogen in the body, which is why they’ve been blamed for weight gain, infertility, cancer, and other problems.

The jury is still out on how harmful these compounds really are, but you generally want to limit your exposure if you can.

Does Microwaving Plastic Release Toxins?

Probably not. 

A study review from the Institute of Health and Consumer Protection found that the amount of chemicals released from plastic bottles isn’t nearly enough to have any impact on your health. This was true even after the bottles were boiled, brushed, and run through the dishwasher.

If you repeatedly heat plastic containers over and over, they do release more chemicals, but the amounts are still well within the current safety guidelines. 

To consume enough of these chemicals to put yourself at risk, you’d have to eat 100-to-1000 times more than the maximum upper limit, and microwaving your food in plastic containers won’t get you anywhere near that amount.

Plastic containers that are repeatedly heated in the microwave can release slightly more chemicals over time, but the amounts aren’t anything to worry about.

Despite the Internet uproar over BPA, for instance, it’s almost impossible to consume enough to cause health problems. For example, you’d have to eat over 500 pounds of canned soup in a day to exceed the tolerable daily limit, and most people consume 10,000 times less than that amount.

That said, there’s always a risk that some of these chemicals could be more dangerous than currently thought, even at low doses. If you want to play it safe, replace your plasticware every few months or as soon as you see visible signs of wear and tear.

Or, store your food in plastic containers and transfer it to a glass or ceramic container before microwaving it.

Microwave Myth #4: Microwaving “Kills” Food

Some people say that food is “alive,” and that cooking kills its beneficial properties, so you should eat all of your food raw.

This, of course, means you aren’t allowed to use a microwave. 

There are two reasons this idea is a nonstarter.

First, more or less everything you eat is dead, regardless of how you store, prepare, or cook it.

Biologically speaking, plants start dying the second they’re harvested, the cells in meat and animal products die soon after the animal does, and frozen foods are dead long before they reach your dinner table.

What’s more, any hint of life that remains in your food is quickly snuffed out the second it hits your stomach acid. In fact, one of the reasons your body has stomach acid is to kill organisms in your food such as bacteria, protozoa, and other pathogens and parasites.

By the time your food exits the stomach and makes its way to the small intestine, almost all living organisms are destroyed. 

Second, whether or not a food is “dead” or “alive” has almost no bearing on its healthfulness. Some nutrients, especially antioxidants, do start to degrade soon after fruits and vegetables are harvested, but that’s true regardless of whether or not the food is cooked later.

Does Microwaving “Kill” Food?

All of the food you eat is dead by the time it enters your digestive system, and even if it were still “alive,” it wouldn’t be any healthier.

Microwaving isn’t going to make your food any “deader” than it already is, and it certainly isn’t going to make your food less healthy.