Some stuff I posted in another thread
Like most issues, GMO shouldn't be looked at in a black or white, good or bad sense. Obviously, it has done many good things, saving many people from dieing from starvation. On the flip side, in areas where people have plenty of food, it has caused many health problems.
I don't have any problem at all with selective breeding. For instance, wheat was created about 5,000 years ago via selective breeding. The things that wheat has done for the world shouldn't need any explaining. The only problem with selective breeding is that it can take thousands of years for the human body to adapt to consuming a new food. In the case of wheat, about 1% of the population has coeliac disease, which is basically an allergic reaction to a particular protein found in wheat. Who knows how long it will be before 100% of the population can handle wheat.
With GMO foods, they alter the DNA of a crop, and they can come up with a lot of new breeds very quickly compared to selective breeding. They can test them all and if they find one with properties that they like, they can start running additional testing on it such as safety or environmental impact. Through gene splicing, they may develop a new crop that can grow in an area where it couldn't grow before. It may save a lot of people from starvation, and that is truly awesome. However, I don't feel that they are tested long enough on humans to know the long term health effects.
Food serves a higher purpose than just filling your stomach. The body breaks it down and uses the vitamins, minerals, and proteins to keep the body going. If a crop is developed that will grow in an area that is deficient in minerals, than that crop just isn't going to have the proper amount of minerals to sustain the human body. People eating those crops will have to get those minerals by other means.
Personally, I feel that if you have the option of eating organic foods that are full of natural vitamins and minerals, or eating GMO crops that may be lacking and require supplementation, you're always going to be better off eating organic. It's the way the human body has always received vitamins, minerals, and proteins, the body knows what to do with it that way because it always comes in the perfect proportions, and there aren't a lot of worries about allergies to new GMO foods or pesticides, herbicides, or other toxins.
Where I see the biggest problems with GMO crops is corporations like Monsanto. Their goal is not to solve the starvation problems of the world, but to wipe out all their competition and control the world's food supply. They create crops that can't reproduce (I'm sure there's a Bible verse that specifically addresses that), and can't grow except by using their own fertilizers, pesticides, and herbicides. Certainly, all GMO developers are not bad, but those that are can be very harmful.
Monsanto is evil. They should have been sued out of existence long ago. They are the creators of Agent Orange, the particularly nasty herbicide that was used in Vietnam, which has caused cancer in thousands and thousands of veterans. The treatment of these cancer cases is paid for by taxes. I don't have a problem with tax dollars paying for the treatment of veterans, but since Monsanto still exists, they should be the ones paying for it.
Monsanto also brought us aspartame. If you don't know anything about aspartame poisoning, research it. Aspartame is actually a GMO. It failed FDA testing until Donald Rumsfeld was hired as CEO of G.D. Searle, and used his political pull in Washington to get it approved by the FDA in 1981. The simple fact that Rumsfeld was involved in getting aspartame its FDA approval should be enough to get most Ron Paul supporters to kick their diet soda addiction.
One of the countries having the most problems with GMO crops is India. Many Indian farmers bought GMO seed from Monsanto. Then they had to buy pesticides, herbicides, and fertilizers from Monsanto because they are all kind of genetically engineered as a set to work together. If they used other products, their crops would die. They also have to re-purchase Monsanto seed every year. Monsanto doesn't allow re-seeding because they hold the patent on that seed, and usually any attempt to re-seed fails anyway because most of them won't reproduce. As a result, many Indian farmers have become deep in debt, and over 150,000 of them have committed suicide since 1993 because that's the only way they see to get their family out of debt.
The problem with eating GMO foods is that your body doesn't know how to handle them. Your body may handle some types of GMO fine, while having really bad reactions to others. Your body will treat some types of GMO as toxins, and either expel them as quickly as possible, give you an allergic reaction to them, or store them in fat cells away from your vital organs. GMO foods aren't properly tested on humans. If you decide to consume them, you are the guinea pig.