# Does microwaving vegetables rob them of their nutrients?
**URL:** https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460
**Category:** Factual Questions
**Created:** [February 22, 2004, 2:59am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460 "2004-02-22T02:59:03Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Torgo](https://boards.straightdope.com/u/Torgo)
#### Post date: [February 22, 2004, 2:59am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/1 "2004-02-22T02:59:03Z")
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?
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### Author:  [@Chairman\_Pow](https://boards.straightdope.com/u/Chairman_Pow)
#### Post date: [February 22, 2004, 4:39am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/2 "2004-02-22T04:39:15Z")
Short answer: Yes. Check out the following thread.
[http://boards.straightdope.com/sdmb/showthread.php?t=136573&highlight=vegetables+steam+nutrients](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.
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### Author:  [@CurtC](https://boards.straightdope.com/u/CurtC)
#### Post date: [February 22, 2004, 4:58am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/3 "2004-02-22T04:58:39Z")
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).
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### Author:  [@aeropl](https://boards.straightdope.com/u/aeropl)
#### Post date: [February 22, 2004, 5:24am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/4 "2004-02-22T05:24:12Z")
> [@CurtC](#):
>
> 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.
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 article](http://news.bbc.co.uk/2/hi/health/3188558.stm)regarding microwaves and antioxidants.
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### Author:  [@barbitu8](https://boards.straightdope.com/u/barbitu8)
#### Post date: [February 22, 2004, 5:39am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/5 "2004-02-22T05:39:36Z")
However, carrots have more beta carotene available if you cook them. Heat causes enzyme changes, causing the production of more of this vital antioxidant.
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### Author:  [@Nametag](https://boards.straightdope.com/u/Nametag)
#### Post date: [February 22, 2004, 7:21am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/6 "2004-02-22T07:21:37Z")
> [@aeropl](#):
>
> 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 article](http://news.bbc.co.uk/2/hi/health/3188558.stm)regarding microwaves and antioxidants.
Perhaps you should READ the article before misquoting it:
> [@](#):
>
> Dr Anne Nugent, a nutrition scientist at the British Nutrition Foundation, said it was the presence of water rather than the cooking process in itself which was the problem.
>
> She said: "It is not the microwaving per se that is causing the antioxidant loss but the presence of water, and boiling.
>
> "In other words, the antioxidants would also be lost upon boiling rather than steaming.
>
> "I think the important thing to take from this article is that when boiling or microwaving broccoli, it is important not to over-cook or over-boil it as this will result in excess antioxidant loss. "
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.
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### Author:  [@aeropl](https://boards.straightdope.com/u/aeropl)
#### Post date: [February 22, 2004, 11:21am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/7 "2004-02-22T11:21:23Z")
> [@Nametag](#):
>
> 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.
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### Author:  [@Phage](https://boards.straightdope.com/u/Phage)
#### Post date: [February 22, 2004, 2:12pm UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/8 "2004-02-22T14:12:06Z")
> [@aeropl](#):
>
> I wasn’t quoting the article I linked to. …
Now, thats just confusing.
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### Author:  [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)
#### Post date: [February 22, 2004, 2:19pm UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/9 "2004-02-22T14:19:10Z")
[This site](http://www.suite101.com/article.cfm/18374/104558) recommends microwaving
> [@](#):
>
> You may use a microwave to cook your foods if you are so inclined. Microwaving does a fantastic job of retaining not only nutrients but flavour as well. The big drawback to microwaving is that you cannot cook up large batches of foods at one time.
Why would anyone microwave vegetables that are submerged in water?
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### Author:  [@Chairman\_Pow](https://boards.straightdope.com/u/Chairman_Pow)
#### Post date: [February 22, 2004, 4:48pm UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/10 "2004-02-22T16:48:10Z")
From the great Mercola himself (if you’re that type): [http://www.mercola.com/article/microwave/hazards.htm](http://www.mercola.com/article/microwave/hazards.htm)
> [@](#):
>
> His small but well controlled study showed the degenerative force produced in microwave ovens and the food processed in them. The scientific conclusion showed that microwave cooking changed the nutrients in the food; and, changes took place in the participants’ blood that could cause deterioration in the human system.
>
> …
>
> Significant changes were discovered in the blood samples from the intervals following the foods cooked in the microwave oven. These changes included a decrease in all hemoglobin and cholesterol values, especially the ratio of HDL (good cholesterol) and LDL (bad cholesterol) values.
>
> Lymphocytes (white blood cells) showed a more distinct short-term decrease following the intake of microwaved food than after the intake of all the other variants. Each of these indicators pointed to degeneration.
>
> …
>
> [From another study]
>
> Microwaving prepared meats sufficiently to insure sanitary ingestion caused formation of d-Nitrosodienthanolamines, a well-known carcinogen.
> Microwaving milk and cereal grains converted some of their amino acids into carcinogens.
> Thawing frozen fruits converted their glucoside and galactoside containing fractions into carcinogenic substances.
> Extremely short exposure of raw, cooked or frozen vegetables converted their plant alkaloids into carcinogens.
> Carcinogenic free radicals were formed in microwaved plants, especially root vegetables.
> Decrease in nutritional value
> Russian researchers also reported a marked acceleration of structural degradation leading to a decreased food value of 60 to 90% in all foods tested. Among the changes observed were:
> Deceased bio-availability of vitamin B complex, vitamin C, vitamin E, essential minerals and lipotropics factors in all food tested.
> Various kinds of damaged to many plant substances, such as alkaloids, glucosides, galactosides and nitrilosides.
> The degradation of nucleo-proteins in meats
Not as well-cited as one might like, but detailing the same experiment a little more: [http://www.karlloren.com/Diabetes/p35.htm](http://www.karlloren.com/Diabetes/p35.htm)
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### Author:  [@CurtC](https://boards.straightdope.com/u/CurtC)
#### Post date: [February 24, 2004, 5:28am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/11 "2004-02-24T05:28:25Z")
Chairman Pow, that Mercola guy you linked to is unbelievably idiotic. Here’s some samples, just for yuks:
> [@](#):
>
> “Microwaved food contains both molecules and energies not present in food cooked in the way humans have been cooking food since the discovery of fire. Microwave energy from the sun and other stars is direct current based. Artificially produced microwaves, including those in ovens, are produced from alternating current and force a billion or more polarity reversals per second in every food molecule they hit.”
>
> “This led Dr. Hertel to the conclusion that such technically derived energies may, indeed, be passed along to man inductively via eating microwaved food.”
>
> "Technically produced microwaves are based on the principle of alternating current. Atoms, molecules, and cells hit by this hard electromagnetic radiation are forced to reverse polarity 1-100 billion times a second. There are no atoms, molecules or cells of any organic system able to withstand such a violent, destructive power for any extended period of time, not even in the low energy range of milliwatts. "
>
> " 2. A loss of 60-90% of the vital energy field content of all tested foods;"
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](http://rabi.phys.virginia.edu/HTW/microwave_ovens.html)
> [@](#):
>
> “Just about any cooking damages the cells of the food being cooked, so microwave cooking is nothing unusual. Since our digestive systems destroy cells in the food we eat, cellular damage in cooking is inconsequential. As for the rumors about the unhealthiness of food cooked in a microwave oven, these are simply myths promulgated by people who don’t understand what microwaves are and fear them irrationally. The world was awash in microwaves from natural sources long before the developments of electricity and microwave ovens.”
>
> “Microwave cooking leaves no permanent mark on the food. It causes virtually no chemical damage and absolutely no radioactivity. The only drawback with heating milk by microwave is that the heating may be uneven and may denature some protein molecules in regions of the milk that become excessively hot. Since most protein molecules are disassembled by your digestion anyway, this treatment probably has no effects worth worrying about. Even with infant formula, my only concern would be the hot spots. If you carefully shake the milk after heating, so that its temperature is uniform, it should be just fine. I suspect that companies warn you not to heat milk in a microwave because they are worried that you will either not shake the milk to distribute its temperature evenly or that you will overcook it until it boils and the bottle explodes.”
>
> “Microwaves don’t affect the molecular structure of the food, except through the thermal effects we associate with normal cooking (e.g., denaturing of proteins with heat and caramelizing of sugars). That’s because, like all electromagnetic waves, microwaves are emitted and absorbed as particles called “photons.” The energy in a microwave photon is so tiny that it can’t cause any chemical rearrangement in a molecule. Instead, it can only add a tiny amount of heat to a water molecule. During the microwave cooking process, microwave photons stream into the food and heat it up. But millions of them would have to work together in order to cause non-thermal chemical changes in the food molecules and they don’t normally do that. The photons can only work together if there is a conducting material, such as a metal wire, inside the oven. In that case, the photons can accelerate mobile electric charges along the conducting paths and create sparks. Such sparks can cause chemical damage, but nothing worse than the chemical damage caused by scorching food with a flame or broiler. Even if your microwave is full of sparks for some reason, I doubt that the food will be any worse for you than it would be if you cooked it over an open flame or barbecue.”
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.
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### Author:  [@Chairman\_Pow](https://boards.straightdope.com/u/Chairman_Pow)
#### Post date: [February 26, 2004, 4:36am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/12 "2004-02-26T04:36:38Z")
CurtC, you obviously ain’t that type.
Speaking of anitoxidents specifically: [http://www.abc.net.au/news/newsitems/s973460.htm](http://www.abc.net.au/news/newsitems/s973460.htm)
From other journals: [http://www.healthatoz.com/healthatoz/Atoz/news/hs515591.html](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.
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### Author:  [@sturmhauke](https://boards.straightdope.com/u/sturmhauke)
#### Post date: [February 26, 2004, 7:17am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/13 "2004-02-26T07:17:43Z")
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.
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### Author:  [@CurtC](https://boards.straightdope.com/u/CurtC)
#### Post date: [February 26, 2004, 3:04pm UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/14 "2004-02-26T15:04:02Z")
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.
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### Author:  [@barbitu8](https://boards.straightdope.com/u/barbitu8)
#### Post date: [February 26, 2004, 9:06pm UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/15 "2004-02-26T21:06:53Z")
> [@CurtC](#):
>
> 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.
> [@](#):
>
> A microwave wreaks havoc because it heats the inside of the vegetable. That, combined with the fact that you normally use water when microwaving, causes the destruction of valuable nutrients.
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.
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### Author:  [@Truth\_Seeker](https://boards.straightdope.com/u/Truth_Seeker)
#### Post date: [February 26, 2004, 11:23pm UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/16 "2004-02-26T23:23:59Z")
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.
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### Author:  [@Go\_You\_Big\_Red\_Fire\_Engine](https://boards.straightdope.com/u/Go_You_Big_Red_Fire_Engine)
#### Post date: [February 26, 2004, 11:55pm UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/17 "2004-02-26T23:55:22Z")
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.
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### Author:  [@Chairman\_Pow](https://boards.straightdope.com/u/Chairman_Pow)
#### Post date: [February 27, 2004, 1:25am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/18 "2004-02-27T01:25:00Z")
> [@CurtC](#):
>
> Chairman Pow, are you saying that I’m “not that type,” meaning I’m not completely kooky?
Yep.
> [@](#):
>
> 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?
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).
> [@](#):
>
> 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.
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.
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### Author:  [@mmmiiikkkeee](https://boards.straightdope.com/u/mmmiiikkkeee)
#### Post date: [February 27, 2004, 7:52am UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/19 "2004-02-27T07:52:19Z")
> [@Chairman Pow](#):
>
> Does the microwave destroy more of the nutrients in food than other methods of heating foods?
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_.
> [@Chairman Pow](#):
>
> According to you, it does **if** it creates more heat than the other methods. I don’t see how the comparison is unfair, however
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.
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### Author:  [@Truth\_Seeker](https://boards.straightdope.com/u/Truth_Seeker)
#### Post date: [February 27, 2004, 5:32pm UTC](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460/20 "2004-02-27T17:32:37Z")
> [@Who Stole My Name?](#):
>
> 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.
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.
> [@](#):
>
> 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.
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.
[http://www.phys.unsw.edu.au/~jw/superheating.html](http://www.phys.unsw.edu.au/~jw/superheating.html)
[Next page](https://boards.straightdope.com/t/does-microwaving-vegetables-rob-them-of-their-nutrients/230460.md?page=2)