Whether you’re heating up leftovers, cooking a quick meal for one or two, or defrosting something that’s been in the freezer for who knows how long, microwaving food is a convenient way to get it from cold to cooked.
But there are a lot of people who are worried about how microwaves might kill nutrients in their foods.
But does that mean we should stop microwaving our food altogether? Is it possible that all those times we’ve heated up our dinners in the microwave have affected their nutritional value?
Let’s take a closer look at this topic and see what research says about how microwaves affect nutrients in food.
Do microwaves kill nutrients in food?
Microwaves are not ionizing radiation, so they don’t break chemical bonds.
However, microwaves do get absorbed by water molecules to cause water molecules to vibrate, which can lead to heat production. It’s actually the heat produced from this reaction that’s a concern for nutrients.
Because microwaves don’t have enough energy to directly break chemical bonds and because microwaving food is extremely quick, it is unlikely that using a microwave to cook will significantly change the nutritional value of food.
Microwaves cook food really fast (potentially from uncooked to cooked within a few minutes) and so there is very little chance that any nutrients will be destroyed in the process.
What does the research show?
Dr. Anthony L. Komaroff from Harvard Medical, explains it:
Research shows that microwaves can be harmful, but not as much as you think
You’ve probably heard horror stories about how microwaves will zap all the nutrients out of your food and make it virtually inedible. While this is true for some types of food, it isn’t for others.
In most cases, the energy from microwaves doesn’t directly affect nutrients. The main component that destroys nutrients is heating. Microwaves don’t generate heat on their own. The heat actually comes from the water molecules boiling out.
Microwaves affect water molecules rather than nutrients themselves
The truth is that microwave cooking doesn’t actually kill any vitamins or minerals. It just causes water molecules to vibrate until it generates heat. The heat then takes its time to cook the rest of the food and, in some cases, potentially destroys the nutrients in it.
Fortunately, microwaves cook food very quickly, so by the time the food is done in the microwave, the cooking process would stop and the food would immediately start cooling.
In most cases, microwaving doesn’t give the heat enough time to actually destroy any major amounts of nutrients.
Longer cooking times increase the risk of nutrient loss over time, but microwaves cook fast
Studies have shown that the longer you cook a vegetable or piece of meat, the more likely its nutrients will be lost during the process.
When food is cooked for a longer period of time (something contrary to the quickness of microwaving food), heat will end up denaturing and pulling apart nutrient molecules.
Nutrients begin to denature around 120 degrees Fahrenheit after a few minutes.
Because microwaves cook food so quickly, the chances of the heat actually getting to the nutrients become slim.
If you compare microwaving to other cooking methods such as boiling or baking, you realize that these kitchen appliances are more prone to destroying nutrients than any microwave is capable of.
Are there any health risks associated with microwaving food?
There are no health risks associated with microwaving food, as far as we know.
Some people worry that microwave ovens might cause cancer or other diseases, but there’s no scientific evidence to support this fear.
The reason for this is that the US government has closely regulated the build and construction of microwaves allowing extremely little radiation leakage allowances for manufacturers when building their microwaves.
These microwaves are built incredibly well and the process of materials we use today virtually limits any leakage from microwaves.
What do microwaves do to the nutrients in food?
Microwaves heat food by causing water molecules to vibrate and move.
This causes the water to expand and push against the cell walls of the food, which eventually breaks down. As a result, nutrients are released from their original location.
This isn’t something out of the ordinary when cooking food.
Any form of heating will naturally destroy the cell walls of food and release nutrients. In a microwave, the nutrients are still usually intact and thanks to how quickly microwaves cook, most of the time nutrients will remain unharmed.
Do microwaves kill nutrients more in leftover food?
In short, maybe.
The concern here is that they’ll be overcooked and dried out faster than if you baked or boiled them in an oven.
Leftovers are more likely to be overcooked than fresh food since the microwave heats up the food from all sides at once rather than cooking it evenly from top to bottom.
Plus, microwaves tend to dry out foods, especially those with less water content (like steamed veggies), which means that you’re already starting off with less water in your leftovers.
If there’s not enough water in your food when microwaving, the chances of burning your food are higher. Burning food almost always leads to destroying nutrients.
Because of this combination of factors, there’s a higher risk of the heat directly damaging even more nutrients when it comes to reheating leftovers.
How does microwave cooking affect nutrients compared to other kitchen appliances?
Microwaves are more efficient than other cooking appliances.
Fortunately, microwaves cook food so fast. safe to say that the nutrients are more likely to impact than most other cooking appliances.
The longer your food is exposed to heat, the more chances that the nutrients in your food will be damaged and destroyed.
Take for example boiling. It takes a really long time to boil food like vegetables. All throughout the process of boiling the chances of nutrients breaking free from the food and leaching out into the water increases. And so your potential loss of nutrients when boiling food is dramatically higher than microwaving it.
Also, baking food in an oven can take several minutes to hours. Also, the temperatures inside an oven can potentially range from 350 to 450 degrees Fahrenheit. Nutrients begin to denature and break apart at around 120 degrees Fahrenheit. This, along with the length of time your food spends inside the oven, can drastically cause nutritional damage to your meal.
Other cooking appliances, like pan cooking and steaming, also use extremely high temperatures and can take longer to cook, meaning that they too can destroy much more nutrients than microwaves do.
Does microwave radiation damage the nutrients?
Microwaves are a form of electromagnetic radiation and should not be confused with ionizing radiation, which causes molecular damage.
No research has shown that microwaves cause any significant damage to food apart from the loss of some nutrients.
The truth is that there’s not enough evidence out there to say whether or not microwaves will destroy all your nutrients (or at least more than normal cooking methods).
One thing is for certain, any cooking appliance can burn your food if you keep it in there for long enough and microwaves are no exception. If you burn your food, then you will certainly destroy the nutrients in it.
It’s probably safe to assume that a microwave can fully cook your food for you, all the while not doing much harm in terms of nutrient loss.
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