19 replies to this topic

[LifeMirage]

Do you have an opinion on microwave ovens in general?

I would avoid them at all costs.

[exigentsky]

I often use the microwave for frozen lunches or to warm up frozen meat. What's so wrong with that? What are the safety issues with microwaves?

[ergosum]

I would avoid them at all costs.

What are your major concerns with microwaves? I can't find any reputable evidence that they are any worse than any other form of cooking food (beyond steaming). But I'm aware that some knowledgable people are against them including yourself, and I'd like to understand why.

[synaesthetic]

10/10/2003 - The November issue of the Journal of the Science of Food and Agriculture contains two studies that examined common food storage and preparation techniques. The studies showed that microwaving vegetables can destroy up to 97% of cancer-preventing antioxidants, and that blanching and freezing can destroy up to 70% of vitamins. Eating fresh fruits and vegetables, combined with vitamin and mineral supplementation, maximizes the protective effects.

In the first study, broccoli lost 97 percent of flavonoids, 74 percent of sinapics and 87 percent of caffeoyl-quinic derivatives (three different types of antioxidants) when it was microwaved. When boiled broccoli lost 66 percent of its flavonoids; when tossed in a pressure cooker, broccoli lost 47 percent of its caffeoyl-quinic acid derivatives. Steamed broccoli, on the other hand, lost only 11 percent, 0 percent and 8 percent, respectively, of flavonoids, sinapics, and caffeoyl-quinic derivatives.

When boiled the conventional way (i.e., not in a pressure-cooker), this green lost 66 percent of its flavonoids; when tossed in a pressure cooker, broccoli lost 47 percent of its caffeoyl-quinic acid derivatives.

Steamed broccoli, on the other hand, lost only 11 percent, 0 percent and 8 percent, respectively, of flavonoids, sinapics, and caffeoyl-quinic derivatives

[xanadu]

How long were the veggies cooked under each system? I've seen referrence to that study before but never heard any details.

[kevink]

I often use the microwave for frozen lunches or to warm up frozen meat. What's so wrong with that? What are the safety issues with microwaves?

One huge problems with microwave "meals" is the use of certain plastics and teflon like materials in the container. They dump a good deal of toxic chemicals into the food because of the heating/microwave process.

Also...some of those meals are actually cooked at the factory in their container and then sealed. I didn't know that until I saw it on TV by accident. That means even if I remove the meal from its container...it's probably already been hit with the chemical leak before it left the plant.

Edited by kevink, 28 January 2006 - 12:17 AM.

[xanadu]

"One huge problems with microwave "meals" is the use of certain plastics and teflon like materials in the container. They dump a good deal of toxic chemicals into the food because of the heating/microwave process."

That is probably true, however, I would like to see some proof of the fact that microwaving selectively destroys vital nutrients. I don't even know of a theory that would explain it.

[kevink]

"One huge problems with microwave "meals" is the use of certain plastics and teflon like materials in the container. They dump a good deal of toxic chemicals into the food because of the heating/microwave process."

That is probably true, however, I would like to see some proof of the fact that microwaving selectively destroys vital nutrients. I don't even know of a theory that would explain it.

I think that was a general question to other people - but just to be VERY clear - I never said that microwaving destroys nutrients. [thumb]

It may or may not - I have no idea.

[Paul Idol]

Xanadu-

I don't even know of a theory that would explain it.

So? If it's true it's true regardless of whether you — or anyone else — can yet explain it.

At any rate, I think the precautionary principle applies here. We know that microwaving can and often does introduce a lot of toxic chemicals to food. There's at least some study data out there which suggests that microwaving destroys a lot of valuable nutrients, though sure, I'd like to see more info. And I've also read that blood testing shows that eating microwaved food causes undesirable radiolytic compounds to show up, though I don't know how reliable that info is.

Is any of this definitive proof that microwaving is bad? Not without more data, at least, and the best proof would be long-term feeding studies, which are about as likely to be conducted as my nose is to start emitting flawless high-carat diamonds whenever I sneeze. But given what's out there, wouldn't you rather be safe than sorry?

Besides, it's not that hard to come up with possible explanations. Microwaves don't heat food evenly along a gradient. My understanding is that they create lots of tiny super-hot zones. The heat from these tiny zones spreads and equalizes over time (within the limits of the macroscopic "evenness" of the oven's heating, anyway, which isn't generally that great) but for brief periods of time, a lot of the food gets heated far beyond any temperatures it would ever reach in conventional cooking systems. Is it any surprise, then, that some components of the food may be altered or damaged in ways and to degrees unseen with other cooking methods?

-Paul

[ergosum]

10/10/2003 - The November issue of the Journal of the Science of Food and Agriculture contains two studies that examined common food storage and preparation techniques. The studies showed that microwaving vegetables can destroy up to 97% of cancer-preventing antioxidants, and that blanching and freezing can destroy up to 70% of vitamins. Eating fresh fruits and vegetables, combined with vitamin and mineral supplementation, maximizes the protective effects.

In the first study, broccoli lost 97 percent of flavonoids, 74 percent of sinapics and 87 percent of caffeoyl-quinic derivatives (three different types of antioxidants) when it was microwaved. When boiled broccoli lost 66 percent of its flavonoids; when tossed in a pressure cooker, broccoli lost 47 percent of its caffeoyl-quinic acid derivatives. Steamed broccoli, on the other hand, lost only 11 percent, 0 percent and 8 percent, respectively, of flavonoids, sinapics, and caffeoyl-quinic derivatives.

When boiled the conventional way (i.e., not in a pressure-cooker), this green lost 66 percent of its flavonoids; when tossed in a pressure cooker, broccoli lost 47 percent of its caffeoyl-quinic acid derivatives.

Steamed broccoli, on the other hand, lost only 11 percent, 0 percent and 8 percent, respectively, of flavonoids, sinapics, and caffeoyl-quinic derivatives

All heating compromises the nutrient and antioxidant content of food. But it seems to have been clearly established that steaming does this the least and microwaving is the next best option -- certainly better than boiling from that point of view. If you read through the links below you will find that the very same study mentioned above found that microwaving reduced the flavonoid content of potatoes and tomatoes far less than boiling did. Also with the broccoli example they were way overcooked in a ricidulous amount of water. Will microwaving a vegetable compromise its nutritional value over eating it raw? Undoubtedly. Is it better or worse than most other cooking methods? All the reading I've done suggests better.

http://www.pritikin....perts/002.shtml

http://www.vegsource...sages/7073.html

http://www.uga.edu/n...eensposter.html

http://www.ncbi.nlm....5405&query_hl=7


I brought up this topic to see if there were any other concerns about microwaves, or rebuttal to any of the info in the articles. It is not a question of microwaving Vs raw/steamed. But microwaving Vs other cooking methods, and microwave ovens in general.

Edited by ergosum, 28 January 2006 - 01:29 AM.

[ergosum]

Great to see the amount of replies my post about microwaves stimulated. But guys and gals you're all raising the same old issues. Might I suggest you have a good through the links I've provided first. The stuff you're all relating so far is a repetition of the alarmist media about microwaves that had me avoiding them for a while myself. All of those points are dealt with in the articles below. But I'm no expert, and I'm interested in any knowledge/research that goes beyond these articles or contradicts any of their findings.

http://www.betterhea...ety_issues?Open

http://www.ncbi.nlm....4486&query_hl=7

http://www.uga.edu/n...eensposter.html

http://www.lessemf.c...-stnds.html#FSA

http://www.pritikin....perts/002.shtml

http://www.vegsource...sages/7073.html

http://www.health.ha...date0604b.shtml

http://66.102.7.104/...u&ct=clnk&cd=13

[ubey]

When microwaving, the lost nutrients from foods seem to leech in the water under it. If you drink the water and eat the heated food do you still lack the nutrients then?

[kerastasey]

Besides, it's not that hard to come up with possible explanations.  Microwaves don't heat food evenly along a gradient.  My understanding is that they create lots of tiny super-hot zones.  The heat from these tiny zones spreads and equalizes over time (within the limits of the macroscopic "evenness" of the oven's heating, anyway, which isn't generally that great) but for brief periods of time, a lot of the food gets heated far beyond any temperatures it would ever reach in conventional cooking systems.  Is it any surprise, then, that some components of the food may be altered or damaged in ways and to degrees unseen with other cooking methods?

-Paul

Yes, that was my understanding. Boiling limits the temperature to 100C, whereas the localised temperatures in microwaved foods causes damaged molecules that can't be metabolised properly. Interestingly, cholesterol increases from eating microwaved foods, even those that don't contain cholesterol.

[xanadu]

Paul Idol wrote:

"So? If it's true it's true regardless of whether you — or anyone else — can yet explain it."

First you must prove it's true. Then we can discuss theories.

"We know that microwaving can and often does introduce a lot of toxic chemicals to food."

No, it is the packaging that has the toxic chemicals, not the microwaves. There is no need for that packaging. I microwave my veggies with no packaging at all and it works fine. The local hot spots theory is interesting but then we see a flock of links to studies debunking the notion that microwaves degrade nutrients more so than other cooking methods. Any heating will degrade some nutrients but do we want to eat everything raw?

kerastasey wrote:

"Interestingly, cholesterol increases from eating microwaved foods, even those that don't contain cholesterol."

Got any proof?

[Shepard]

Interestingly, cholesterol increases from eating microwaved foods, even those that don't contain cholesterol.

That statement doesn't prove anything. Dietary cholesterol has minimal impact on cholesterol levels. Was this study done with microwave meals?

Could it be that microwave meals have been processed, with most of the carbs ending up with a relatively high glycemic index....which could have caused the rise in cholesterol? I bet it could.

Here is the question we should all be asking ourselves: What Would Methuselah Do?

[rfarris]

Are your jugs clear or cloudy plastic?

I beg your pardon?

[tung]

[xanadu]

QUOTE (kevink)
Are your jugs clear or cloudy plastic?

The jugs I used to use, no longer use, were the ordinary cloudy jugs used for milk or water. You see them all over. Do you mean to tell me no one else has noticed the plastic taste? If you can taste it, you know chemicals are in there.

[curint]

QUOTE[/b] (xanadu)<!--QuoteEBegin]kerastasey  wrote:

"Interestingly, cholesterol increases from eating microwaved foods, even those that don't contain cholesterol."

Got any proof?

What is your problem xanadu. There were good explanations on the Potassium-R-Lipoic Acid thread ( http://www.imminst.o...=6&t=9023&st=20 ) about why you can't PROVE anything in science. You should have learnt that in 5th grade.
Why do you keep asking for what you know is impossible to give?
Or put it another way - tell us what would prove it to you, and we'll provide it. I can prove it to you. Just tell me the nature of the proof you're looking for. Can you do that?

Edited by curint, 29 January 2006 - 09:55 PM.

[kevink]

uggh - is everyone arguing again?

Just make sure not to hit me with the cross fire! [wis]

[ergosum]

Yikes. My innocent question on microwaving V. boiling started a war. Now I know why they're considered dangerous!