This product sits in more than 90 percent of kitchens, as well as practically every break room in the country.
In fact, it’s so common you might be surprised to know I didn’t even have one for most of our married life (over 7 years now).
That was until quite recently, when we were given one.
If you use your microwave every day in life, you might find it hard to imagine how you could do without it.
The funny thing is, we did just fine without one. But, now that it’s in the home, I do find myself using it.
I certainly wouldn’t use it every day, but do sometimes find it convenient to heat a plate of leftovers, rather than reaching for the pots and pans.
In recent years, I have questioned whether we’re paying for it in terms of our health by using the microwave, even just a little bit.
Microwave safety is one of those controversial topics, but I refuse to mindlessly believe the party line, “Microwave ovens just heat food,” without doing my own research on the matter.
I understand that microwaves heat food, but how do they do that, and does it somehow effect the nutritional quality of our food?
So, I started doing my own research to find out, and I want to share my findings with you here today.
How Microwaves Work
Firstly, let me tell you how microwave ovens actually heat food.
It gets a little technical, but I’ll try to keep it brief (my eyes were glazing over a little as I researched this, so I don’t want that to happen to you!)
Inside your microwave, there is a magnetron, which creates an alternating current. This acts on the electrons in food, increasing its kinetic energy, which creates heat, and cooks the food.
For a more technical explanation, Swamy Anantheswaran, Penn State professor of food science, explains what microwaves are actually doing to our food;
Microwaves do most of their work on the water in food… Water molecules constitute what are known as ‘dipoles.’ A dipole is sort of like a bar magnet, with a positive pole and a negative pole. The oven’s electromagnetic field oscillates as it passes through the water molecules in the food, changing the polarity of the field and causing the dipole/water molecules to flip themselves in order to be aligned with the new polarity. Heat is created by the resulting friction of the water molecules reversing direction millions of times a second.
So, the reason you sometimes get uneven heating using a microwave, is because not all areas within the food contain the same amount of water, leading to hotspots.
Are Microwaves Safe?
Okay, now that we sort-of get how microwave ovens heat our food, what about the issue of transforming your home into a radiation zone?
Microwaves do emit radiation, that is clear.
The FDA have issued what they consider to be safe levels, stating;
A Federal standard limits the amount of microwaves that can leak from an oven throughout its lifetime to 5 milliwatts (mW) of microwave radiation per square centimeter at approximately 2 inches from the oven surface. This limit is far below the level known to harm people. Microwave energy also decreases dramatically as you move away from the source of radiation. A measurement made 20 inches from an oven would be approximately one one-hundredth of the value measured at 2 inches.
This suggests, that as long as you are standing far enough away from the microwave while it’s working, you shouldn’t be too much at risk. This does, however, assume your microwave is in good repair.
I freely admit, I do not feel comforted by that at all.
One major problem with microwave use, is the containers people use to reheat, usually plastic, or coated paper.
So, if you are going to use a microwave, make sure you completely remove the food from it’s packaging, and use glass where possible to reheat.
To be honest, I am actually more concerned about what microwaving does to the nutrients within my food.
What’s the point of spending a lot of money at the supermarket to bring home wholesome produce, simply to blast the nutrients out of it in a few seconds flat?
So, lets look at the available research, to see are microwaves safe after all?
Unsurprisingly, the studies on this topic are pretty mixed.
Some research suggests microwave ovens are not detrimental to the nutritional quality of our foods. One study concluded;
No significant nutritional differences exist between foods prepared by conventional and microwave methods. Any differences reported in the literature are minimal.
Another study using Brassica vegetables (e.g.cabbage, turnip, Brussels sprout, etc.) found that microwaving resulted in similar nutrient loss, compared to steaming, or stir frying;
Cooking by steaming, microwaving and stir-fry did not produce significant loss of glucosinolates whereas boiling showed significant losses by leaching into cooking water.
Low Power May Help
Other research suggests that if food is cooked on a low power setting, there is equal or better retention of nutrients using the microwave, compared with conventional methods;
With the utilization of low-power techniques, studies showed equal or better retention of nutrients for microwave, as compared with conventional, reheated foods for thiamin, riboflavin, pyridoxine, folacin, and ascorbic acid.
There are, however, a considerable number of studies which have found microwaving may have a detrimental effect on foods.
It seems antioxidants are most at risk, while minerals tend to be more easily preserved.
In one study using broccoli, researchers found it lost up to 97 percent of its beneficial antioxidants. By comparison, steamed broccoli lost 11 percent or fewer of its antioxidants;
Clear disadvantages were detected when broccoli was microwaved, namely high losses of flavonoids (97%), sinapic acid derivatives (74%) and caffeoyl-quinic acid derivatives (87%). Conventional boiling led to a significant loss of flavonoids (66%) from fresh raw broccoli, while high-pressure boiling caused considerable leaching (47%) of caffeoyl-quinic acid derivatives into the cooking water. On the other hand, steaming had minimal effects, in terms of loss, on both flavonoid and hydroxycinnamoyl derivative contents.
In a study of garlic, researchers concluded that as little as 60 seconds in the microwave was enough to inactivate its allinase (garlic’s main active ingredient against cancer);
These studies suggest that heating destroyed garlic’s active allyl sulfur compound formation, which may relate to its anticancer properties.
Inert Vitamin B12
Another study found that heating milk for 6 minutes in the microwave turned 30-40 percent of the vitamin B12 in milk into an inert (dead) form. They concluded;
These results indicate that the conversion of vitamin B12 to the inactive vitamin B12 degradation products occurs in foods during microwave heating.
A further study on breast milk, found that it lost lysozyme activity, antibodies, and became a more suitable environment for the growth of pathogenic bacteria, after being microwaved.
Microwaving appears to be contraindicated at high temperatures, and questions regarding its safety exist even at low temperatures.
One study showed that microwaves cause a higher degree of “protein unfolding” than conventional heating. This is a complicated area of research, but this “unfolding” is not a good thing;
Microwaves cause a significantly higher degree of unfolding than conventional thermal stress for protein solutions heated to the same maximum temperature.
While the evidence is a bit mixed, you may be like me, and believe giving up the microwave is probably the better option.
But, how is that possible?
How To Cut Your Microwave Habit
If you’re interested in freeing yourself from your microwave, here are some tips…
1. Plan Ahead
Take your dinner out of the freezer the morning you need it, or the night before, so you don’t end up trying to defrost before you can even begin cooking.
This is a really important tip to help you eat well, too.
I cannot tell you how many times I’ve arrived at dinner time, feeling a little lethargic about cooking, but become spurred on by the fact that I’ve already taken the meat out of the freezer, and dinner will be ready in no time, if I just put my mind to it.
If you find your meat or fish is still a little frozen, run come cold water over it to defrost. I do this all the time — it’s a little trick I learned from chefs in the restaurant I worked with, while studying at uni.
2. Cook In Bulk
Get into the habit of making soups, curries, and stews in bulk, and then freeze them in freezer bags, or other containers.
That way, all you need to do is take it out and defrost for dinner later in the day.
3. Use The Oven
I know it’s not as quick as ‘pinging’ meals in the microwave, but it’s a decent alternative.
If you have a toaster, or separate grill in your main oven, these make good faux microwaves for heating leftovers. You will need to make sure the temperature is pretty low, and it usually takes around 20-30 minutes.
A convection oven is another obvious alternative. If I am re-heating food in the oven, I usually cover it (as least for a while) with a layer of foil, to prevent the food getting too dry.
It may also be a good idea invest in some smaller pots and pans for reheating/cooking single servings, or smaller cooking jobs. This is definitely worthwhile, and washing them will feel like much less of a chore.
What do you think, are microwaves safe? And, have you any useful tips for avoiding or minimizing microwave use?