November 18

Does Microwaving Food Kill Nutrients? | Is Your Food As Good As Ever?


Author: Cornelia Suehr and its partners may earn a commission if you purchase a product through one of our links.

Does microwaving food kill nutrients? Some nutrition experts claim that "natural" foods are always better, but there is no evidence to support this idea. Eat various foods to get all the vitamins and minerals you need for good health is essential. But if you choose one type of food over another, for example, fruits and vegetables over meat, you may miss out on some essential nutrients.

The idea of microwaving foods began in the 19th century with attempts to use microwave radiation to thaw foods quickly. Today, microwaves are used extensively in hospitals and restaurants to heat, reheat, and sterilize food.

Woman smilling in front of a microwave

What's Microwave Cooking?

Microwaves are a type of energy that travels extremely rapidly through space or along with a wave. The frequency of microwaves is the same as the frequency on your oven's dial. Microwaves cause water molecules to vibrate faster, which raises the heat in food, thus cooking it.

When you microwave foods with high water content, such as vegetables, the water heats first. Once cooked, microwaving can kill some of the nutrients in food by causing the cells to break open. Boiling vegetables or microwaving fruits for too long will also make them lose color and essential vitamins and minerals. But your food may be exposed only briefly to microwaves, so very few nutrients are lost.

How Microwaves Work

A microwave oven sends out waves of energy that cause water and fat molecules in foods to vibrate. The food heats up as these molecules rub against one another, generating heat. Microwaving food for too long can damage it by pushing the outer layer to break down and release its nutrients. The microwave radiation does not leave the oven so that you can put solid items on glass or metal plates without fear of harm.

Microwaves are radio waves produced in a magnetron device, which is similar to a vacuum tube. The magnetron causes the positive and negative charges of microwaves to oscillate, creating a wave sent out from an antenna at the oven's opening. These waves cause water molecules to move faster as they pass through food, producing heat.

Healthy cooked food

Cooking Food in Microwaves

Fresh fruits and vegetables are among your best choices for healthy foods. Many vitamins, minerals, and natural chemicals that may improve your health are found in these foods. They also contain fiber and other substances that help prevent heart disease and cancer. But microwaving reduces vegetables' vitamin C content more than other cooking methods.

While you lose some vitamin C when you microwave fruits and vegetables, most of the vitamins are in the skin or the outer layer. It's true for carrots, apples, and other fruits and veggies. So you can effectively cook these foods without damaging their nutrients by using a microwave with an open door or placing them on a plate before microwaving them. Whichever method you use, be sure to pierce the skin of potatoes to release steam and avoid them exploding.

Four heart shaped plates with food

How Does Microwave Cooking Affect The Nutritional Value of Food?

Some nutrients are bound by plant cells. This process is called gelatinization, and vitamins are sometimes dissolved in the water inside the cell walls. Over boiling veggies remove nutrients from the food, and they end up in your cooking water. If you drink this water after it has cooled down, you will absorb some of these lost nutrients into your body.

Your microwave oven at home is quick and reduces your time in the kitchen. But when it comes to cooking vegetables, consider using other cooking methods to retain their nutrients. For instance, steamed fruits and vegetables have more nutrient value than microwaving them.

Why You Should Use a Microwave

Whether or not microwaving kills existing nutrients depends on if the water molecules are heated to the boiling point. If they are, you should eat right away because this can cause some soluble vitamins to evaporate into the air. 

You should also avoid microwaves if you want to cook potatoes without creating acrylamide, a potentially deadly chemical that forms when carbohydrates are heated at high temperatures (see 1100 Watt ovens). According to the American Cancer Society, this chemical has been linked to cancer and neurological problems in animals.

Microwave ovens tend to be safe because they only work with non-ionizing radiation. Ionizing radiation can cause chemical reactions that harm human cells by damaging their DNA. Microwave ovens only work with the non-ionizing type of radiation that does not have enough energy to break chemical bonds.

It's a myth that microwaves kill nutrients in food. While cooking or heating any food will reduce the number of nutrients it contains, microwaving isn't any worse than other types of heating. It would help if you kept in mind that while microwave ovens kill germs and bacteria, they do not cook food from the inside out like other cooking methods. So you need to make sure that your food reaches an internal temperature of at least 165F, which is not a problem for new 900 Watt ovens, to kill all of the harmful microbes inside.


Does Microwaving Kill Nutrients In Your Food?

Microwaving food helps kill bacteria and other microbes that may harm your health. It also helps reduce the chances of overcooking, which keeps nutrients from being leached out into your cooking water. So, if you're looking for a quick way to prepare fresh fruits and vegetables without losing their nutritional value, microwave cooking is one of the best.

What are Microwave Safety Hazards?

Glass containers are not safe in the microwave because they can shatter, so it's best to avoid using them. Even if your glassware doesn't crack, it may still be unsafe. It could have "crazing" on its surface caused by high heat. This crazing is permanent damage that weakens your dishware and makes it less resistant to thermal shock.

Like all ceramic ware, Porcelain should be tested before using in the microwave oven. If you pour cold water into a hot dish or drop a wet paper towel on its surface, it may crack. It makes it less safe and increases the chances that it will break if you microwave food.

Some plastics, like styrofoam, do not microwave safe because they can release toxins into your food. So, never use these plastic containers to store or reheat foods in the microwave. Polycarbonate plastic is also unsafe.

Pill with healthy food

What About Microwave Ovens Safety?

It's not safe to use an oven without a metal tray, so all microwaves must have one inside. If the microwave doesn't have a metal tray or it's damaged, never use it. It could cause your appliance to overheat, catch on fire, or electrocute you.

Microwaves should be divided into older appliances with metal mesh covers and newer microwave models with glass fronts. If your oven's door has a metal grid in the glass, it is okay to use. Even so, care must be taken when opening the door because this mesh is not always perfectly sealed to the glass. It causes electric arcing, which you can see if there are tiny sparks around the edge of your door when it closes. If your microwave doesn't look like this, it may have had its metal grid removed and replaced with a trim piece of plastic.

 To ensure that your oven is safe, check your microwave door for a metal mesh cover or a label that says "Suitable for Microwave Oven Use." If you find either, then your oven is safe to use. It doesn't mean it's perfect, though. It could still have other issues like damaged cords and glass-door seals, making it unsafe to use.

Microwave Ovens and Health: To Nuke, or Not to Nuke?

So you want to microwave your food. But is it safe? And does it kill the nutrients in your food or even cause cancer? You've probably heard horror stories about microwaves and electromagnetic radiation.

Rainbow of food

The truth is, microwave ovens are safe. They're safer than cooking food on the stove. Any method of cooking involves some risk. The problem with most cooking methods is that you don't control your cooking time very well. While a steak needs to be cooked at a high temperature for a short amount of time, a potato needs to be cooked at a lower temperature for a longer time.

Microwaves are the only cooking method to set your oven, press start, and do something else for ten minutes. When your food is done cooking, it will stop on its own. You'll never overcook broccoli again because microwaved broccoli is evenly heated and comes out well cooked every time.


Microwaves are safe to use as long as you take care when you buy, store, and operate them. Glass-front microwaves are considered safe for use because they have metal trays. It would be best if you avoided older models (see also modern retro microwaves) with only mesh covers no matter what because of the risk of electric arcing causing a fire. Harmful radiation in a microwave oven can only be produced if the power cord is damaged.

About the author

Cornelia Suehr

A professional chef and a passionate writer on all topics related to cooking, baking, appliances and kitchenware. Her posts resonate with foodies, home chefs and professionals.


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