Posted by Larry Hoover on September 11, 2004, at 6:21:09
In reply to Re: Dioxin Carcinogens causes cancer » Larry Hoover, posted by KaraS on September 9, 2004, at 19:12:01
> > > Some info you might find interesting. Johns Hopkins has recently sent this out in their newsletters...worth noting...
> >
> > Johns Hopkins sent this out? Are you sure? It's a well-known urban legend, and the text exactly matches your own quotes....
> >
> > http://urbanlegends.about.com/library/bl-microwave-dioxin.htm
> >
> > In my work for the World Wildlife Fund Toxicology Program, I assessed the risk of exposure to humans and animals based on plastic monomers (what plastics are made from, such as ethylene which makes up polyethylene, and so on), and the additives which modify the physical properties of plastics (plasticizers, etc.). I can assure you, no dioxin is produced or released in a microwave. The minimimum temperature for dioxin to form is around 600 Celcius, and only in certain oxygen concentrations. Also, no "dripping" of carcinogens from plastic wrap occurs.
> >
> > Not all "microwave safe" plastic ware is actually microwave safe, but the majority of it is. The stiffer the plastic, the more likely it is to be safe, but that's not a perfect rule. Better to use e.g. corningware, or corelle dishes, or the like. If you do cover food with plastic wrap, ensure it does not touch the food. The migration of plasticizers depends on contact. Migration is enhanced by fat. Some plasticizers and plastic monomers are endocrine-gland disrupters. Once that was recognized, government regulations have completed changed e.g. food packaging for microwavable foods. I won't declare those regulations to be perfect, but routine testing of consumer products is being carried out. You don't have to repackage or change the container type for microwavable food, but I guess it wouldn't hurt.
> >
> > I appreciate the intent of your post, Jai. Really. If anyone has further questions or concerns, please go ahead and ask.
> >
> > Lar
>
> Excuse me for butting in here but I wanted to ask you how it is possible to keep plastic wrap from touching the food?A) I don't consider this to be butting in.
B) As the steam under the wrap condenses, the pressure falls, and the wrap is sucked down onto the food. So long as you don't leave it there long, there is a minimal risk. I was speaking more to wrapping a pile of food, say a meal on a dinner plate, where the food is intimately touching the wrap during the warming (or storage in the fridge....the combination of such storage and subsequent heating is the worst case). In such a circumstance, toothpicks would probably serve well, to form a tent. Or use a container with side walls.> Even if I don't have it touching the food when I insert it into the microwave, the wrap always ends up touching the food when I take it out.
Just don't leave it long.
> Also, are microwave ovens and microwaved food all that safe to begin with? I use them but worry about it. I've read that it can actually change the chemical composition of food.
There are chemical changes in all cooking. Try to uncook an egg. Can't be done, eh?
> For example, I read that baby formula when heated by microwave can change it to include a complelely new form of amino acid. Don't know if that's complete b.s. or not. What do you think? Better yet, what do you know?
Some amino acids can be isomerized under microwave heating. Some fatty acids can isomerize, too. As a proportion of the whole, though, those changes are really quite small. Not significant, in fact.
Certainly, this effect is not limited to baby formula. It was a study of baby formula, though, published in The Lancet in 1989, that raised the flags of worry. The fact is, the change reported was small, is not unique, and is not worrisome.
The conversion of L-amino acids to D-amino acids goes on all around you, all the time. Fermented foods are full of D-aminos, the result of metabolic processes going on in yeast and bacteria. Beer has generally got greater than 10% of its aminos in the D-isomers. The older a cheese is, the more D-aminos it might have (crude generalization, but pretty accurate). Some of the toxic effects of certain bacterial infections or food contaminations arise, in part, because of D-amino mediated effects, but those cases are exceptions. There is no general concern about fermentation.
The real risk in microwave heating of formula is esophageal burns caused by the uneven heating of the formula itself. All you have to do is shake the bottle thoroughly before checking the overall temp.
Lar
poster:Larry Hoover
thread:387808
URL: http://www.dr-bob.org/babble/social/20040907/msgs/389560.html