My wife says that if I microwave frozen veggies, as opposed to steaming them or whatnot, I’ll lose the nutrients that make them so healthy. I’ve heard the same thing about boiling vegetables. Is this true?
Short answer: Yes. Check out the following thread.
http://boards.straightdope.com/sdmb/showthread.php?t=136573&highlight=vegetables+steam+nutrients
There was another thread that I thought I bookmarked and can’t find via search that actually had percentages of nutrients that were lost per different methods of cooking if you want to look for it.
To clarify, heating up veggies does break down some of the nutrients. Mircorwaves are no worse than heating up to the same temperature any other way. The alternative is to eat veggies raw, which would probably cut down on how much of them you eat, therefore reducing your intake of these nutrients.
On the other hand, if you eat a better than average diet, you get all those nutrients you need even if they’re heated (I’m basing this on the fact that the average person doesn’t need more vitamins than what he gets in his diet).
That’s not true, according to the research that’s been posted to this board before. Apparently, steaming removes the least amount of nutrients. Boiling is the second best method, and even better if you consume the water (but depending on the nutrient). Microwaving turned out to be the worst for most nutrients. Here’s a BBC articleregarding microwaves and antioxidants.
However, carrots have more beta carotene available if you cook them. Heat causes enzyme changes, causing the production of more of this vital antioxidant.
Perhaps you should READ the article before misquoting it:
No normal person boils vegetables in the microwave, but only steams them everywhere else. It’s asinine to compare steaming vegetables on a stovetop to boiling them in a microwave oven. If one merely steams them in the microwave oven, one will discover that vegetables retain MORE of their flavor and character (and, I dare say, their nutrients) than with any other method.
I wasn’t quoting the article I linked to. The study that I recall reading didn’t have to do with broccoli specifically and probably didn’t have to do with antioxidants either. I think we have to remember that some nutrients can be destroyed by heat and some aren’t affected. I’m trying to find a study saying that microwaves destroy the former type of nutrients, in a way that steaming or boiling doesn’t.
Now, thats just confusing.
This site recommends microwaving
Why would anyone microwave vegetables that are submerged in water?
From the great Mercola himself (if you’re that type): http://www.mercola.com/article/microwave/hazards.htm
Not as well-cited as one might like, but detailing the same experiment a little more: http://www.karlloren.com/Diabetes/p35.htm
Chairman Pow, that Mercola guy you linked to is unbelievably idiotic. Here’s some samples, just for yuks:
And it goes on and on. It’s so completely ridiculous that I’m wondering whether this is a parody web page, along the lines of Landover Baptist Church or the Creation Science Fair.
Here’s the deal with microwaves. Each little packet of energy doesn’t have the intensity that would be required to break chemical bonds, so it can’t chemically alter food, unless it just heats it up so much that the heat breaks down the chemicals, and of course this would apply to food heated with any method. Here’s an actual fact-based site: http://rabi.phys.virginia.edu/HTW/microwave_ovens.html
There are a whole lot more facts on that page, and reading it all the way through should be a good antidote to the Mercola site.
CurtC, you obviously ain’t that type.
Speaking of anitoxidents specifically: http://www.abc.net.au/news/newsitems/s973460.htm
From other journals: http://www.healthatoz.com/healthatoz/Atoz/news/hs515591.html
I did skip a couple of sites that showed that microwaves may actually be better for nutrient retention than other methods of cooking, but the references to “reputable” studies were nonexistant (if studies were even mentioned). I left off the cookier sites that would take the same view I do.
Well the crap about “direct current” vs “alternating current” microwaves is patently false. A photon is a photon is a photon, it absolutely doesn’t matter how it’s generated, only the wavelength matters. If it doesn’t have a wavelength of a few millimeters, it’s not a microwave anymore, maybe it’s an x-ray, or green light. Besides, the sun doesn’t use electricity to generate photons, it uses nuclear fusion. If Mercola can’t get basic science right I’m not going to listen to anything he has to say.
Chairman Pow, are you saying that I’m “not that type,” meaning I’m not completely kooky? After your first post, I had the impression that you were intentionally posting nonsensical links just to show how some people think. Were you posting that seriously?
The fact is that microwaving itself cannot destroy nutrients, but the heat can. If you’re comparing raising something’s temperature to 100C by steaming or boiling, versus microwaving it to 200C, then of course microwaving in this case would break down more chemicals. But that’s not a fair comparison.
From the last link posted. In any event, the “good” doctor, Dr. Mercola, states that microwaves are harmful, not merely that nutrients are lost, which does not appear to be supported by any reliable authority.
One key point that’s being missed is that boiling vegetables can leach a lot of water-soluble nutrients into solution whereas microwaving/steaming doesn’t.
Don’t quote me on this, but I learned that Microwaving cooks by transferring heat from water molecules vibrated by the microwaves to the food. It only affects water molecules, which being invariably stable are unlikely to affect your food.
Boiling is the worst method.
I was just wondering this, how high are the temperatures that can be created by a microwave? Since water becomes vapour at 100 degrees celsius, and air is not the best conductor of heat, I imagine it wouldn’t be that high.
Yep.
They are to show how some people think. As noted in the intro to the second link (possibly not clearly enough), the commonality between the two links in my first post was the Blane/Hertel study. The Mercola link was indeed posted as it contained information regarding the study, I figured that people would separate the study from the commentary. If you have a problem with the any of the studies in the link (as sturmhauke does), we can argue those. Let’s get back to the OP though, rather than argue alterna-medicine semantics (or wackiness).
Getting back to the OP… Does heating food in the microwave destroy its nutritional content? Maybe. Does heat destroy nutrients in food? If it’s hot enough, yes. Is the microwave hot enough to do this? Assuming it goes to 200C as you posit, yes. Do other methods of heating foods destroy nutrients? If they’re hot enough, yes. Does the microwave destroy more of the nutrients in food than other methods of heating foods? According to you, it does if it creates more heat than the other methods. I don’t see how the comparison is unfair, however.
Perhaps my mistake was not clarifying my position in the initial post. Can we agree on the above paragraph? If not, let’s clarify that, then we can argue about bio-energy fields, AC vs. DC and everything else.
No.
Since it’s the heat that degrades the nutrients, if you are going to compare two methods of heating against each other and look at the results you have to use the same heat in both.
It appears as though you’re applying admittedly different temperatures to food, but judging the results as though the two devices applied equal heat and saying one does more damage than the other which is misleading. The if above is the unfair part. There would be no if’s in a fair comparison since there would be no special circumstances for one method that did not apply to the other.
Your example could easily be turned around and stated as such:
“Steaming degrades nutrients far more than microwaving if you cook the food 10X longer using high-pressure steam”. With this format you’re not actually making a comparison at all; just stating a rather obvious fact that isn’t very relevant.
Actually, microwave ovens will affect any dipolar molecule. There are lots of them besides water. That’s why, for example, some plates are “microwave safe” and others aren’t.
The boiling point isn’t really applicable here, since the water vapour can also be heated by microwaves. It’s quite easy to heat steam past 100C.
In fact, it’s also easy to heat liquid water past 100C in a microwave. If you put a container of water in a microwave and heat it, under certain conditions, it can become “supeheated,” and literally explode from the container, causing injury.