The mysterious microwave, whether you hate ’em or love ’em, you can’t deny they have revolutionized the way we cook many foods. “Just nuke it” is a very common term in my household. But can something so quick and convenient actually be good for us? Are nutrients lost when we cook food in the microwave? When I was traveling in Nicaragua last summer there was not a microwave in sight. My Nicaraguan home-stay father proudly proclaimed, “Nicaraguans don’t use microwaves because they make the food taste bad and they cause cancer.” At the time I shook my head yes and agreed with Jorge, mainly because arguing in Spanish about “microndas” would be very difficult. Surviving three months without a microwave got me thinking 1) maybe microwaves aren’t really necessary 2) perhaps slow-cooked food is better for us? Let’s take a look at the science.
Claim #1: Microwaves destroy healthy nutrients in food.
False. In fact, microwaving is one of the best methods for retaining nutrients in food. Nutrient loss happens when foods are cooked for long periods of time and when they are boiled in water. For example, broccoli loses much of it’s vitamin C and spinach will lose it’s folate when boiled. The microwave allows you to cook foods quickly with little added water. Cooking fresh or frozen veggies in the microwave is one of the healthiest and easiest ways to get veggies on the table quickly. You can either buy a microwave steamer or just put veggies in a bowl with a few tablespoons of water. Cover the bowl with a microwave safe lid, cook for a couple minutes, and voila, you have perfectly steamed vegetables. Make sure to cover your dish to avoid “hot spots” that may affect nutrient retention.
Claim #2: Microwaves cause cancer.
Sorry Jorge, this one is also false. Microwave ovens are designed so that the microwaves are contained within the oven itself. According to the American Cancer Association when microwave ovens are used correctly, there is no evidence that they pose a health risk to people. In the US, federal standards limit the amount of radiation that can leak from a microwave oven to a level far below what would harm people. Ovens that are damaged or modified, however, could allow microwaves to leak out, and so could pose a hazard to people nearby by potentially causing burns.
Claim #3: Styrofoam is not safe to put in the microwave.
It depends. According to Harvard Health Publications some Styrofoam and polystyrene containers (what you usually get from a restaurant) can safely be used in the microwave. Check the container for the “microwave safe” label. If it doesn’t say, it’s best to swap it out for a different dish.
Why so much confusion on this topic?
If you look around the internet you’ll see varying opinions on this topic. The issue is most research on microwaves, especially with nutrient loss, focus on a specific Vitamin, phytochemical or protein. While one study may show one specific vegetable had more loss of polyphenols than other forms of cooking, another study will show it increased retention of a different nutrient. It’s important to look at all the data to see the entire picture.
In conclusion, “nuking it” may very well be one of the best cooking options. I recently started making corn on the cob in the microwave and it comes out perfectly cooked! Find out how to make it here. As long as you are putting more than just hot pockets and frozen burritos into the microwave, there is no need to see it as an inferior/less nutritional cooking method.
Heather Mason is a Registered Dietitian who holds a Master’s Degree in Nutrition Science. She has a passion for debunking nutrition myths and helping people discover delicious and healthy food. You can read more posts from her on her blog, Nutty Nutrition.