April 1, 2009
Microwaves a parenting issue? You betcha. And if I ever had any doubt, it evaporated when my mom made a snarky comment about zapping all of the nutrients out of Isaac’s peas. Was I really sacrificing nutrition and taste quality for convenience? All while ravaging the planet? Great. Bad mom and eco-pirate. I needed to know more. And given that, according to Wikipedia, 90% of American homes currently have a microwave, I think I’m not the only one.
There are several dimensions to the debate on microwaves: environmental impact, effect on nutrition, effect on taste, and convenience. The latter isn’t an issue for those who’ve always lived without a microwave but, for the rest of us, I think it’s safe to say that microwaves can provide incredible convenience. But what about the other issues? Is using the microwave worth it? There’s a lot of ground to cover… here we go!
Microwaves and the environment
Raymond Blanc once said that using a microwave oven to cook food for your children was an “act of hate”. There’s just something about these humming masses of metal and glass that makes foodies shudder in revulsion. But there is a growing view that we need to reassess our attitude.
“These screwy views are typical of people who don’t understand microwave cookery, and inhabitants of the green kitchen should ignore them,” argues Richard Ehrlich, author of the recently published book The Green Kitchen. He adds that microwave ovens can be one of the most energy-efficient ways to cook and should be used more widely to help reduce carbon emissions.
A recent Brown University study found that microwaves can use just 3 units of energy compared to 16 used by an electric oven and 7 by a gas oven, but only for certain tasks. The consensus is that microwaves generally save energy when it comes to warming or re-heating small amounts of previously cooked foods and steaming veggies. Check out Tree Hugger for tips on figuring out the greenest way to heat your food, including a simple equation for thinking through your microwave use.
Microwaves and nutrition
A pattern quickly emerged in my research: there is wide disagreement over every aspect of microwave use that will, like other age old questions (paper or plastic? chicken or egg?), go on forever. The most hotly contested question has to do with the microwave’s effect on nutrition. Surprisingly, most of the cited resources I scoured report that microwave ovens do not kill nutrients and, depending on how you use them, may even help retain nutrients! The abstract for a study entitled “Nutritional effects of microwave cooking” in the Journal of Nutrition Food and Science sums up:
Several studies have shown that microwave cooking, if properly used, does not change the nutrient content of foods to a larger extent than conventional heating. In fact, there is a tendency towards greater retention of many micronutrients with microwaving, probably due to the shorter preparation time.
While I had a hard time finding cited resources that present the other side, the argument is that the molecular friction microwaves use to heat foods destroys vitamins and phytonutrients. The Organic Consumers Association published an article that refers to (but, unfortunately, doesn’t cite) a study claiming that microwaving vegetables destroys up to 97% of the nutritional content. Many other online articles ask: if microwave ovens can zap bacteria, can’t they also zap important minerals and nutrients? It’s a compelling question and I understand why many believe that it must, but most research I found points to “no.” Anyone have links to credible research on this?
Microwaves and taste quality
Here’s where foodies get all worked up. Me included. Even knowing that “baking” a potato in the microwave can save energy, I’d be hard pressed to do it. What about all that precious, nutritious, crunchy skin that the conventional oven yields? No microwave can manage that. But as Mark Bittman discovered last year, in some instances, the microwave achieves results just as good as the conventional oven. His conclusion: “…if you can steam it, you can microwave it. But only with vegetables was the improvement clear.”
Which brings us full circle. If you want to do more than quickly reheat leftovers or steam veggies, you’re back to weighing your convenience against the impact your microwave use has on the environment and quality of your food.
The bottom line
Your best bet on all fronts–environmental, health, and taste–is to stick to quick reheats and steaming fresh or frozen veggies. But if you want to do more with your microwave, here is a quick synopsis of what works and what doesn’t:
So, that’s the low down. Not conclusive, but at least you can make an informed decision. As for me, I’m going to stick to re-heating small portions of leftovers and steaming veggies. I don’t have the constitution for more than that. And, anyway, Michelle has just “enlightened” me to the fact that microwaves kill our foods’ prana (i.e., life force). (I haven’t yet asked what makes the microwave more of a prana killer than the conventional oven. Maybe she’ll fill us in?) Let us know if–and how–you come to another conclusion.
Lemony Steamed Asparagus w/ Crumbled Feta (or grated Parmesan)
(can be adapted for kids 8+ mos)
1 bunch fresh, organic asparagus, cleaned & trimmed
2 tbsp freshly squeezed organic lemon juice (the juice of about 1 lemon), plus 2 1″ pieces of lemon zest (skip lemon entirely for kids under 12 mos)
1/4 cup water
1 tbsp organic olive oil
organic feta, crumbled OR parmesan, finely grated
salt and pepper
1. Place asparagus in a microwave safe dish (ideally made of glass). Add the water, 1 tbsp lemon juice, and lemon zest. Cover, leaving one corner open for venting. Microwave for 2-3 minutes.
2. Transfer asparagus from microwave safe dish to serving dish. (Honestly, you can eat it at this point–it’s so lemony!) Add olive oil and remaining lemon juice. Sprinkle with feta or parmesan. Season older kid and adult portions with salt and pepper.
Bittman’s instructions for steaming veggies:
Put the vegetable in a bowl with a tiny bit of water (or sometimes none), cover, and zap for approximately…
Additional reading on microwaves: