That’s a pretty good argument, but I still haven’t seen any serious evidence that genetically-modified food is any different from Gregor Mendel’s experiments.
ALLERGIC REACTIONS FROM GENETICALLY ENGINEERED FOOD Genetic engineering can actually result in unexpected allergens and toxins in food and reduced nutritional value. Pioneer Hybrid, a seed breeding company in the U.S., decided to remodel soybeans to give a more balanced protein by introducing a gene from Brazil nuts. It resulted in a soybean that had a balanced amino acid composition because it had more methionine in it. The problem was that after they had spent several million dollars and several years, they discovered almost by accident that this same protein caused the soybeans to be allergenic so that it was not safe to put on the market. Even so the Food and Drug Administration (FDA) gave Pioneer Hybrid permission to put it on the market. Pioneer Hybrid realized there would be a risk of cross contamination and litigation caused by people getting sick or maybe dying because allergic reactions are not always mild. So they did a very wise and ethical thing and wisely chose not to market this product.
TOXINS IN GENETICALLY ENGINEERED FOOD The next story illustrates how toxins can be produced by genetic engineering, and it does not have such a happy ending. A Japanese company named Showa Denko had been producing the amino acid tryptophan for many years by extracting it from natural bacteria, and people had been getting good results with it. Tryptophan is used as a natural relaxant. They then had the great idea that if they genetically engineered these bacteria to produce tryptophan in larger amounts and more efficiently it would be more profitable for them. Because the laws in the U.S. are very sloppy about these things, they were allowed to put this on the market without any safety testing whatsoever. As a result within a few months, about 5,000 people became sick and 1,500 of those are still sick today. They were permanently disabled by the toxin in this tryptophan and 37 of them actually died. It is the opinion of many scientists that genetic engineering caused this bacteria to produce toxic tryptophan. A study published in Science (250, 1990) found that Showa Denko's tryptophan was contaminated with a "novel amino acid" not normally present in tryptophan.
REDUCED NUTRIENTS IN GENETICALLY ENGINEERED FOOD There is an example of a genetically engineered food which had reduced nutritional value, and you may be familiar with it. The FLAVR-SAVR tomato was introduced several years ago, but it tasted so bad that they had to take it off the market. It was designed to be stored for at least six weeks and still look beautiful. This was called "extended shelf life", and it was done by destroying the product of one gene that is involved in the decay process. The problem is that the decay process is a complex one and involves more than one gene, so even though those tomatoes continued looking beautiful on the shelf, the decay process continued to occur inside the tomato and reduced the nutritional value.