Microwaves and Your Health
There is a wide array of opinions regarding microwaves and their effect on your health. Microwaves are incredibly convenient and get the heating job done, but do we truly understand their impact on our food? First, let's start with learning how microwaves actually work!
How do microwaves work?
Microwaves use microwave radiation, a form of electromagnetic radiation, to heat the food. There are many levels of EM, ranging from shorter wavelengths (x-rays and gamma rays) to longer wavelengths (radio waves). Microwaves fall right in-between radio waves and infrared waves. Microwaves work by creating movement at a molecular level, primarily working on water molecules. The water molecules start to rotate, causing friction which turns into heat, heating the rest of the molecules in the food rapidly.
How do microwaves affect your food?
Microwaves can affect the nutritional content of your food.
The cooking methods we use significantly affect the nutritional content of our food. Heating foods, in general, can have effects on the nutrient makeup of foods. The macronutrients and minerals seem to remain unharmed by microwave radiation, but the vitamins are the nutrient that takes the biggest hit. A study done by the Journal of Agriculture and Food Chemistry found that food microwaves had a general decrease in all studied compounds (glucosinolates, phenolic compounds, minerals, and vitamin C) except for the minerals. Vitamin C saw the most significant loss due to degradation of the compound and leaching into the water (3.) The phenolic compounds and glucosinolates were mainly lost through leaching into the water. "In general, the longest microwave cooking time and the higher volume of cooking water should be avoided to minimize losses of nutrients" (3.)
Acrylamide is a neurotoxin and carcinogenic substance that has been recently discovered in food, (4.) Microwaving meals has been shown to vastly increase the acrylamide formation in the food. A 2020 study found that heating your food with a microwave at high power levels can cause greater acrylamide formation than food heated in conventional heating methods: stovetop or oven, (4.)
When we microwave things in plastic containers, the plastic heats up enough to leach small plastic particles into our food. BPA and phthalates are released from the plastic, which increases the toxic load on our bodies. The consumption of plastics has been known to be harmful to human health and should be avoided as much as possible.
Safer Heating Methods
So if the microwave is not the best option for reheating foods, what can be done?
Microwave with low power:
There is still not enough research to say whether or not low power microwaving is beneficial for your health, but it can cause less nutrient content loss than when using a microwave on high power. So if you are strapped for time or a microwave is all you have present, opt for using it on a lower level of heat (Hoffman, 1985.)
Cook your food daily:
This might sound like quite a feat, especially if you have a hectic work schedule, a family, or if there is limited access to a full kitchen. But doing your best to prepare meals fresh, when possible, will preserve the nutrient content of your food and prevent mold formation.
Cross, G. A., & Fung, D. Y. (1982). The effect of microwaves on nutrient value of foods. Critical reviews in food science and nutrition, 16(4), 355–381. https://doi.org/10.1080/10408398209527340
Hoffman, C. J., & Zabik, M. E. (1985). Effects of microwave cooking/reheating on nutrients and food systems: a review of recent studies. Journal of the American Dietetic Association, 85(8), 922–926.
López-Berenguer, C., Carvajal, M., Moreno, D. A., & García-Viguera, C. (2007). Effects of microwave cooking conditions on bioactive compounds present in broccoli inflorescences. Journal of agricultural and food chemistry, 55(24), 10001–10007. https://doi.org/10.1021/jf071680t
Michalak, J., Czarnowska-Kujawska, M., Klepacka, J., & Gujska, E. (2020). Effect of Microwave Heating on the Acrylamide Formation in Foods. Molecules (Basel, Switzerland), 25(18), 4140. https://doi.org/10.3390/molecules25184140
Michaelson S. M. (1974). Effects of exposure to microwaves: problems and perspectives. Environmental health perspectives, 8, 133–155. https://doi.org/10.1289/ehp.748133