![[dr. bob]](/dr-bob-sm.gif)
Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 20 of 20. This is the beginning of the thread.
Posted by mike99 on February 27, 2006, at 18:06:52
My roomate microwaves food on styrofoam plates, which makes me cringe.
Is it safe for me to microwave my own food--in microwavable-safe plates/cups, etc. in the same microwave?
Posted by linkadge on February 27, 2006, at 18:06:52
In reply to How bad is it to microwave styrofoam?, posted by mike99 on February 19, 2006, at 9:10:33
Good question. I hate microwaves. I open my microwave door with a stick, I am afraid to go near it after I saw that 60 minautes special on "leaky microwaves".
Linkadge
Posted by Larry Hoover on February 27, 2006, at 18:06:52
In reply to How bad is it to microwave styrofoam?, posted by mike99 on February 19, 2006, at 9:10:33
> My roomate microwaves food on styrofoam plates, which makes me cringe.
>
Styrofoam is made from expanded polystyrene beads. Heating styrofoam in a microwave causes the release of styrene. Heating food on styrofoam in a microwave enhances styrene release, and allows the chemical to migrate into food.Styrene is an endocrine-disrupting chemical. It's roughly on par with Bisphenol A, and the phthalate plasticizers for toxicity.
I question the use of styrofoam for food containers for any application. But in any case, styrofoam is not microwave safe.
http://www.grinningplanet.com/2005/11-01/styrofoam-cups-article.htm
> Is it safe for me to microwave my own food--in microwavable-safe plates/cups, etc. in the same microwave?
I don't expect that there would be any toxic carryover. You have nothing to worry about.
Lar
Posted by mike99 on February 27, 2006, at 18:06:52
In reply to BAD BAD BAD SUPER BAD » mike99, posted by Larry Hoover on February 19, 2006, at 10:11:57
Thanks for the info, Lar.Would you mind my asking why you wouldn't expect there to be any toxic carryover (ie styrene being unstable?)?
Thanks again.
Posted by jakeman on February 27, 2006, at 18:06:52
In reply to BAD BAD BAD SUPER BAD » mike99, posted by Larry Hoover on February 19, 2006, at 10:11:57
Jeez, I practically live off take-out food and coffee provided in styro-foam containers. Now I'm wondering about the safety of non-disposible plastic containers, like tupperware.
~Jake
Posted by teejay on February 27, 2006, at 18:06:52
In reply to Re: How bad is it to microwave styrofoam?, posted by linkadge on February 19, 2006, at 9:18:27
Its not paranoia if your microwave really IS out to get you ;-))))
Sorry :-)))
TJ
Posted by Phillipa on February 27, 2006, at 18:06:52
In reply to Re: BAD BAD BAD SUPER BAD » Larry Hoover, posted by jakeman on February 19, 2006, at 14:09:24
Jakeman it should say microwave safe. Fondly, Phillipa
Posted by tealady on February 27, 2006, at 18:06:53
In reply to BAD BAD BAD SUPER BAD » mike99, posted by Larry Hoover on February 19, 2006, at 10:11:57
what do you think of this?
Whatever form of gelatin is used, it should never be cooked or reheated in the microwave. According to a letter published in The Lancet, the common practice of microwaving converts l-proline to d-proline. They write, “The conversion of trans to cis forms could be hazardous because when cis-amino acids are incorporated into peptides and proteins instead of their trans isomers, this can lead to structural, functional and immunological changes.” They further note that “d-proline is neurotoxic and we have reported nephrotoxic and heptatotoxic effects of this compound.”55 In other words, the gelatin in homemade broth confers wonderous benefits, but if you heat it in the microwave, it becomes toxic to the liver, kidneys and nervous system.Another study suggested that the l-configuration and the proper molecular size are both essential for beneficial effects of l-proline upon memory and for the prevention of depression. 56 There is no reason to think that proline is the only amino subject to this kind of destruction, and it is likely that other aminos would be similarly affected. The studies, however, were done on proline.
http://www.westonaprice.org/foodfeatures/brothisbeautiful.htm
54. Pottenger. 55 Lubec, G, et al. Amino acid isomerisation and microwave exposure, Lancet, 1989, 2, 8676, 1392-1393.I know its not chemical toxicity, but I haven't been able to find any other studies confirming or negating this.(and when I last looked that year was only half online..so that paper wasn't available.. must look again sometime:)
In the meantime.. I get these phases where I decide to avoid the microwave.. but they don't last long..Jan
Posted by linkadge on February 27, 2006, at 18:06:53
In reply to Hey linkadge.............., posted by teejay on February 19, 2006, at 19:47:20
No it freaked me out. I was listeing to a portable radio, and I started to notice that as I walked around the kitchen listening to this thing the reception started to go all heywire evertime I got near the operating microwave !!!!!!!
Freaky eh, then I saw the 60 minautes thing on leaky microwaves so I put two and two together.
I should really toss the thing !
Linkadge
Posted by Larry Hoover on February 27, 2006, at 18:06:53
In reply to Re: microwaves .. » Larry Hoover, posted by tealady on February 20, 2006, at 3:18:24
> I know its not chemical toxicity, but I haven't been able to find any other studies confirming or negating this.(and when I last looked that year was only half online..so that paper wasn't available.. must look again sometime:)
> In the meantime.. I get these phases where I decide to avoid the microwave.. but they don't last long..
>
> JanConsidering that fermentation leads to significant isomerisation, yielding in some cases 7-10% of total aminos in the D-conformation, I'm not too worried about any adverse effects from brief microwave bursts on protein-rich food.
I tried to find similar studies in Pubmed, and came up with a couple of later studies that found undetectable D-isomerisation of aminos, so it looks like that earlier study was not replicated by other researchers.
As to issues of toxicity specific to D-proline, there are a couple of rodent studies which may put your mind at ease. Rodents loaded with D-proline enriched food did not change brain levels of D-proline. Instead, renal excretion went up dramatically. Control rodents also had substantial amounts of other D-enantiomer aminos, absent any manipulation.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9140753
Also, in studies of acute toxicity in hippocampus, the L-proline isomer was the primary neurotoxin, not the D-isomer.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3409032So, I conclude that the lone study declaring substantial transformation of proline to the D-form is inconsistent with other evidence. Whatever worries might arise from using a microwave, transformation of amino acids does not seem to be of concern.
Lar
Posted by Meri-Tuuli on February 27, 2006, at 18:06:53
In reply to Re: microwaves .. » tealady, posted by Larry Hoover on February 20, 2006, at 12:37:47
Along the same lines, (this is something I have been wondering for a long while) how safe is it to put those shop bought ready meals which are in those plastic containers in the normal oven?? Obviously, the plastic doesn't melt or anything like that, but it seems abit dogdey to me! I mean, I still do it sometimes, but I might now start transferring the meal into a pyrex dish we have. From what I know as an ex science teacher, the plastic must be those 'thermosetting' kind, which doesn't melt, but still.....
I read somewhere that actually eating and drinking are more carcinogenic to humans than smoking but obviously we have to eat and drink!! Apparently things that are burnt are massive culprits, along with melted (when it goes bubbly brown) cheese.
To add my two cents to the microwave debate, an Editor of the 'journal of radiological protection' I worked with refused to own a microwave....
Posted by Larry Hoover on February 27, 2006, at 18:06:53
In reply to also, food in plastic containers normal ovens??, posted by Meri-Tuuli on February 20, 2006, at 15:01:41
> Along the same lines, (this is something I have been wondering for a long while) how safe is it to put those shop bought ready meals which are in those plastic containers in the normal oven?? Obviously, the plastic doesn't melt or anything like that, but it seems abit dogdey to me! I mean, I still do it sometimes, but I might now start transferring the meal into a pyrex dish we have. From what I know as an ex science teacher, the plastic must be those 'thermosetting' kind, which doesn't melt, but still.....
The way I try to divide up things is to consider managing those factors that are in my control. I can control the placement of food in the microwave or conventional oven. I can ensure that it is in ceramic or glass, at the cost of one more dish to clean.
Same goes with the food itself. In my opinion, all food is contaminated with heavy metals and pesticides and dioxins and stuff, because we use Mother Earth like a dustbin. But that's largely out of my control, because I don't grow/harvest my own food. So, I select foods based on the good things they contain. What I select is in my control. What might sneak into my diet via the food I select is not. E.g. farmed fish is good for me, even though it might contain contaminants.
> I read somewhere that actually eating and drinking are more carcinogenic to humans than smoking but obviously we have to eat and drink!! Apparently things that are burnt are massive culprits, along with melted (when it goes bubbly brown) cheese.
It's interesting how that is, actually. The flavours that draw us into liking foods that are burnt obviously don't arise except under conditions manipulated by we smart human beings. First we had to harness fire. And then we had to create cheese from milk. So, how is it that nature draws us towards those toasted flavours? And yes, many of those flavour molecules are carcinogenic.
That's one reason that blood that passes through the digestive tract, picking up nutrients, also goes through the liver, before it gets to your body. There are molecules that your liver doesn't want your body to experience.
> To add my two cents to the microwave debate, an Editor of the 'journal of radiological protection' I worked with refused to own a microwave....
Hmmm. Seems extreme.
I remember when I first started discovering just how toxic some chemicals can be, and how we were being exposed to them. For a while there, there was nothing left to eat. Everything was contaminated. But I had to stand down from that position of vigilance. There's a pragmatic middle ground.
Lar
Posted by Meri-Tuuli on February 27, 2006, at 18:06:53
In reply to Re: also, food in plastic containers normal ovens?? » Meri-Tuuli, posted by Larry Hoover on February 20, 2006, at 17:04:24
Hi Lar,
Good post. Thats what I try and do too. Otherwise you could get pretty extreme! I completely stay away from artifical sweetners, MSG etc etc and eat as many fruit veg (particulary those from the brassica family and (blue)berries.....) as possible.
It really annoys me all this intensive farming, Wal-Mart Monopoly stuff. In the long term, intensive farming just isn't worth it. For instance, mad cow diease here in the UK was caused by cattle eating feed made from infected sheep - its just not right feeding herbivores meat remains!!
Posted by mike99 on February 27, 2006, at 18:06:53
In reply to Re: also, food in plastic containers normal ovens? » Larry Hoover, posted by Meri-Tuuli on February 21, 2006, at 3:40:53
Or does this question not really make sense?
Posted by Larry Hoover on February 27, 2006, at 18:06:53
In reply to how hot does it get inside microwaves?, posted by mike99 on February 21, 2006, at 11:43:36
>
> Or does this question not really make sense?It gets extremely hot, but only in places where the microwaves are absorbed.
I'll try an analogy. A tuning fork can be made to resonate sound energy if it is itself exposed to the right frequency of sound. A wine glass can resonate to a voice of the correct pitch, causing it to shatter. That's because masses of certain specific sizes and spacing have characteristic resonance frequencies. If you match the masses and the distances and the exciting frequencies properly, you'll get resonance. The energy of the waves will be absorbed and propogated.
In the case of microwave energy, those waves are matched nicely with the masses of, and bonds formed between, atoms which are bonded together into molecules. Water molecules have characteristic resonance frequencies for the bonds between their hydrogen and oxygen atoms. The "temperature" of a water molecule is really the amount of vibrational energy it has in its bonds. If you can match the vibrational frequency of water molecules with an energy wave, the water will absorb that energy, and exhibit the energy as heat. Microwave frequency radio waves do just that. They match the frequency of water molecules' heat vibrations, and the molecules dance with heat.
Individual water molecules that have absorbed all this extra energy vibrate so much that they bump into all the molecules around them, and transfer the vibrational energy, by conduction. That cools the water a bit, but that water molecule is once again free to absorb the next microwave that happens by. Rotating the position of moist food inside a microwave oven allows the greatest opportunity for water molecules to be oriented properly to best absorb microwave energy, because the waves are directional within the oven. Turn the food the right way, and you maximize resonance. And the hot water molecules that are oriented so as to absorb the wave warm the rest of the food up. That's also why it's best to stir the food around, half way through warming it. The heating is a random process, in some respects.
There are other resonance frequencies for common food molecules that also match up nicely with the microwave frequency band used in microwave ovens, but the example with water is probably the most common one we use when cooking. You add some water to some dishes, to provide the absorption capacity to surround the food with heat (as steam, or hot water vapour). Fatty food also absorbs microwave energy. Melting butter in a microwave oven is a snap.
An earlier question asked about styrofoam. Styrene molecules can absorb microwave energy. Zapping styrofoam creates styrene vapour, and you don't want styrene vapour next to your food. Other plastics don't absorb any microwave energy (they act like windows, letting the microwave "light" pass right on through), so they are "microwave safe".
I hope that explains the physical chemistry a little bit. Questions welcome.
Lar
Posted by mike99 on February 27, 2006, at 18:06:53
In reply to Re: how hot does it get inside microwaves? » mike99, posted by Larry Hoover on February 21, 2006, at 12:47:11
Thanks for the excellent explanation, Lar. It's been a while since I've taken physics but that really helped to clarify exactly what I was wondering about.
About the styrene vapour--- wouldn't you say it's at least somewhat likely that I could contaminate my food/drinks with styrene by sharing the same microwave with someone who uses styrofoam in it (I know you responded to this earlier)?
I'm just wondering if that vapour can't hang around in the air or deposit within the interior of the microwave and then get into my food when I microwave my food.
With such a toxic compound as styrene unless I'm absolutely certain about the possibility of contaminating my food/drinks I'd prefer to err on the side of caution (which will likely mean lots of cold cereal in my future:(
Posted by tealady on February 27, 2006, at 18:06:53
In reply to Re: microwaves .. » tealady, posted by Larry Hoover on February 20, 2006, at 12:37:47
Posted by Larry Hoover on February 27, 2006, at 18:06:53
In reply to Re: how hot does it get inside microwaves? » Larry Hoover, posted by mike99 on February 21, 2006, at 17:15:08
> Thanks for the excellent explanation, Lar. It's been a while since I've taken physics but that really helped to clarify exactly what I was wondering about.
You're welcome. If I wasn't dealing with some disruptive medical issues, I would think I'd be a teacher-geek in the real world. Like a professor or something.
> About the styrene vapour--- wouldn't you say it's at least somewhat likely that I could contaminate my food/drinks with styrene by sharing the same microwave with someone who uses styrofoam in it (I know you responded to this earlier)?
Sorry I failed to address this thoroughly. Styrene vapour is very highly volatile. The reason it would be dangerous in the context of food on a styrofoam plate is the direct contact. The styrene would "rather be" a vapour (from a physical chemistry perspective) than be dissolved in the food. But if it gets into the food, it stays there for at least a little bit of time. Long enough to swallow it, anyway. Vapour phase styrene would dissipate to irrelevantly small concentrations quite quickly. Modern microwave ovens have fans and venting (to carry away steam, mostly), so you have no cross-contamination issue to worry about.
> I'm just wondering if that vapour can't hang around in the air or deposit within the interior of the microwave and then get into my food when I microwave my food.I know of no tendency for styrene to absorb to plastic or metal or any other parts inside a microwave. Non issue.
> With such a toxic compound as styrene unless I'm absolutely certain about the possibility of contaminating my food/drinks I'd prefer to err on the side of caution (which will likely mean lots of cold cereal in my future:(Warm cereal is in your future. I can see it, in my crystal ball.
Lar
Posted by Larry Hoover on February 27, 2006, at 18:06:54
In reply to Re: microwaves .. Thanks Lar :) (nm) » Larry Hoover, posted by tealady on February 21, 2006, at 20:07:20
Posted by joslynn on March 5, 2006, at 22:31:01
In reply to How bad is it to microwave styrofoam?, posted by mike99 on February 19, 2006, at 9:10:33
Now they are saying this is very bad too.
When I was younger, I remember I had a kind of raggedy teflon pan. Yikes!
Fortunately, being a domestic non-goddess, my disklike of cooking saved me from using it much!
Still, one wonders.... will I get sick one day because of Teflon I used years ago?
But I guess that I should probably worry a lot more about long-terms effects of Lexapro. Would that be better or worse than Teflon, microwave, etc.
It makes my head spin.
I guess I can only make the best compromises I can.
This is the end of the thread.
Psycho-Babble Health | Extras | FAQ
Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.org
Script revised: February 4, 2008
URL: http://www.dr-bob.org/cgi-bin/pb/mget.pl
Copyright 2006-17 Robert Hsiung.
Owned and operated by Dr. Bob LLC and not the University of Chicago.