For this reason, Kosher certification agencies typically monitor food production all over the world. You can read about it here; it's really quite fascinating. Besides the Kosher aspect, it gives great insights into industrial food production; not really one for the squeamish.
Anyway, I mentioned Kosher in a previous article, on the grape-flavoured apples. It occurred to me; are genetically modified organisms which would otherwise be considered Kosher still Kosher?
GM food is big business, and getting bigger every day, especially now that the EU has started to allow its production. Generally, GM food consists of a standard plant (no animals yet, really, though some are in trials) with one or more genes or pieces of genetic material from elsewhere added. The genes really can come from anywhere; sources include bacteria, jellyfish, and even humans.
Bizarrely, to my mind, consensus seems to be that GM plants are Kosher, even if the genes added are from something non-Kosher. I do wonder, though; just how much do you have to change something for it to become non-Kosher? Birds, in particular, are subject to weird Kosher rules; while land animals and fish are generally accepted or rejected based on physical criteria, like presence of cloven hooves or scales, there is a list of birds generally considered acceptable. When is a chicken not a chicken?
For that matter, where do vegetarians stand on plants incorporating animal or bacterial genetics? Hindus? Jains? It'll be interesting to see how this one pans out, I think.
Vaccines are another thing. Many vaccines are animal-based. The standard Polio vaccine at least used to be, and as far as I know still is, made on a monkey (unquestionably non-Kosher) liver base. Kosher seems to allow essential medication, but, again, what do vegetarians think of this? Of course, most people probably don't actually know about it, but I wonder do people ever reject vaccines or other essential drugs on the basis of their diet?