Posted by Larry Hoover on February 20, 2006, at 12:37:47 [reposted on February 27, 2006, at 18:06:53 | original URL]
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
poster:Larry Hoover
thread:613889
URL: http://www.dr-bob.org/babble/health/20060202/msgs/613899.html