Explainer: Are microwave ovens bad for health

Explainer: Are Microwave Ovens Bad for Health?

The shortest answer is no. Under normal use and in consideration of proper observance of quality standards observed by manufacturers, using microwave ovens to prepare food is perfectly safe for human health.

Purveyors of misinformation, both online and offline, have long claimed that using microwave ovens result in a range of negative health effects ranging from diminished nutritional intake to debilitating diseases such as cancer. However, these assertions have been rejected by the scientific community.

This article compares the prevailing myths against established scientific facts about the safety of using microwave ovens.

Microwave cooking myths: Using microwave ovens is not bad for health

1. It destroys nutrients in food: Heating and cooling naturally result in changes in the physical and chemical properties of raw food. To be specific, cooking using a microwave, conventional open, or a cook top, and specific processes such as grilling, boiling, baking, and reheating, among others changes the nutritional profile of the food.

The correction combination of time and temperature is central to proper cooking and of course, nutrient preservation. In an article published by the Harvard Medical School, microwaving food does better in preserving the nutrient profile of the food than other types of cooking processes such as boiling and baking. A microwave oven heats food at high temperature for the shortest amount of time. It essential steams food from the inside out.

Boiling results in nutrients leaching out of the cooking water. Baking causes substantial changes in physical and chemical properties due to prolonged exposure to heat. Frying or broiling also does the same. These cooking processes involve subjecting food under high temperatures under a considerable amount of time.

2. It causes cancer: A microwave oven heats food using a form of electromagnetic radiation that has a higher frequency than radio waves but lower frequency than infrared and the visible light. Food heated using microwaves does not become radioactive. The microwave does not remain within the food as well.

Essentially, microwaves are non-ionizing radiation that do not pose the same risks as ionizing radiation. Other types of non-ionizing radiation are radio waves, infrared, and the visible light. On the other hand, forms of electromagnetic radiation such as higher ultraviolet rays, x-rays, and gamma rays are ionizing radiation with more energy that can damage tissues and cells at the molecular level.

The World Health Organization explained that no traces of microwaves remain after the microwave oven is turned off. In other words, similar to the visible light, when a light source such as a light bulb is turned off, no light remains.

It is also worth mentioning that microwaves widely used in wireless communication technologies and protocols such as 3G and 4G network standards and wireless home networks. Hence, they are generated by cellular base stations, WiFi routers, and mobile phones, among others.

Safety of microwave cooking: Risks associated with using microwave ovens

1. Associated health issues: Most of the actual health issues associated with microwave cooking stem from improper food preparation, the nature or characteristics of the food, the type of food, and inappropriate use of microwave ovens.

Cooking food reduces the risk of food-borne illnesses by killing microorganisms through high temperature. However, a notable problem with microwave cooking is the uneven distribution of temperature due to the physical characteristic of the food. For example, microwave ovens need more time to evenly heat thick cuts of meat or layers of food. Uneven heating can leave some microorganism in the food unscathed.

Furthermore, most disease-causing microorganisms die at a temperature above 60 degrees Celsius, but the harmful toxins they produced might be tolerant from heat. Like in any other cooking methods, while subjecting the food under high temperature can kill the bugs, microwaving might not be enough neutralize the bug-produced toxins.

The nature of food is also a health issue. Although it is a commonly held belief that microwaving is bad for the health, this notion actually stems from the fact that most food items cooked using a microwave are ready-made and thereby, loaded with preservatives.

Containers such as extruded polystyrene foam and low-grade plastics should not be used in microwave cooking. High temperatures can break down the chemical properties of these containers and create toxic substances that can contaminate the food.

Another health issue associated with microwave ovens involves inappropriate use. The U.S. Food and Drug Administration reminds the public to always follow the instruction of manufacturers and always check for leakages or damages.

While microwaves are non-ionizing radiation, they can still be absorbed by the body and produce heat in exposed tissues. Eyes and other organs with low blood supply and poor temperature control, as well as heat-sensitive tissues like the testes can be harmed from long exposure to microwave energy.

2. Other safety risks: Both the WHO and the U.S. FDA mentioned that most of the reported emergencies associated with the use of microwave ovens are due to burns or thermal injuries from hot containers, overheated food, and super-heated liquids.

In the same way food and containers are cooked or heated using a conventional oven, proper handling should be taken into consideration to avoid injuries. Use potholders or allow both the food and container to cool before handling.

Super-heated liquid poses the greatest risk in using microwave ovens. For example, using stovetops and pots to boil water allows heat to escape as indicated by the presence of bubbles and steam. However, microwaving liquid induces heat to build up with no indicators of thermal movement. A slight disturbance triggered by a movement or an introduction of a foreign item may cause the water to suddenly boil and explode. Reported incidents like these often involve serious skin burns and scalding injuries.

Food with nonporous surfaces such as sausages or those made of components with different thermal response can also explode when cooked in a microwave due to built-up heat.

Conclusion: Microwave ovens are generally safe

Microwave ovens are not bad for health. Understanding how microwave cooking affects the physical and chemical properties, and nutritional profile of food and its safety risks requires an understanding of how a microwave oven works. There is no scientific research to support the claims about the health and safety risks associated with microwave cooking.


  • Harvard Health Publishing. 2017. “Microwave Cooking and Nutrition.” Harvard Health Publishing. Harvard Medical School. Retrieved online
  • United States Food and Drag Administration. 2017. “5 tips for using your microwave oven safely.” For Consumers. U.S. Food and Dug Administration. Retrieved online
  • World Health Organization. 2005. “Electromagnetic fields and public health: Microwave ovens.” Electromagnetic Fields. World Health Organization. Retrieved online