Genetically altered food - evidence of benefit or harm?

Peter McQuillan peter.mcquillan at stonebow.otago.ac.nz
Mon Apr 21 13:34:26 EST 1997


Eric Grunden wrote:
> [other interesting stuff]
>
> I guess what scares me is Novartis' Bt corn, which is coded to fight > insects in a product that is consumed by people and animals. 
> However, this may be able to be taken care of in the processing of 
> the corn, I don't know....................any ideas?

The safety issues here seem fairly clear (at least from my angle).  
The _Bacillus thuringiensis_ insectical protein has been licensed as 
an insecticide since 1962.  The protein is eaten by the pest and 
hydrolysed in it's gut to the active form, which results in paralysis 
and eventual death.  Hundreds of thousands of tonnes of the protein 
have been used since that time, with very few instances of harm noted.  
There are multiple variants of the protein, from different strains of 
the bacteria, which specific for different moth species - almost no 
interspecific toxicity between protein variants.  No mammalian effects 
have been reported.  There was recently an aerial spraying programme 
in Auckland, New Zealand, in which 70 planeloads of this protein were 
used in an attempt to eradiate an imported moth pest species.  No 
adverse effects attributable to the pesticide were reported.

My only real concern about licensing of such a product would be the 
potential for allergenicity, or toxicity associated with long term 
use.  Given that traditional use of the _B.thuringiensis_ pesticide is 
external to the plant, the amount ingested will be small.  Expression 
of the protein in the plant will result in a much higher protein load 
being absorbed.  While most of this protein will be digested normally 
there is the potential for an allergic response to develop in 
susceptible individuals.  Consequently, if the product is released for 
domestic consumption it should have appropriate warning labels.

The FDA regulations for approval of novel food stuffs containing 
proteins not usually in the food supply are fairly comprehensive, and 
I'm confident that they should provide a high level in confidence.
For a review of FDA's position see - Miller, H.I. (1990) Foods of the 
future:the new biotechnology and FDA regulation. JAMA;269:910-912. 

I guess I'm more interested in finding examples of novel foods which 
have been approved by the FDA and have later caused toxicity or other 
concerns.


Peter.


Another point - would a company release a product which is they think 
is going to cause health problems and probably get them sued into 
bankruptcy?  Then again, look at thalidomide....



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