neoolong wrote:What exactly are scratch tests? And is it only a small number of things in fish that potentially cause allergic reactions? Can it be that something will not cause an allergic reaction in one person that is allergic to fish and yet someone will be affected?
Haven't you every had a scratch test? I thought that is something that everyone takes some time in their life.
The basic idea is simple. You have a person who you are testing to see whether something is an allergen. A person is given a small scratch and the substance that they are testing is applied to the scratch. If they are allergic to the substance, there will be a reaction beyond any normal reaction to the substance.
In the case of a genetically engineered tomato triggering fish allergies, it would be simple. The FDA holds a cattle call for people who are known to have allergic reactions to fish. Three scratch tests are given. The first is the whitefish that they got the specific gene from to confirm that they are allergic to the fish. The second is an ordinary home grown tomato, to confirm that they are not allergic to tomatoes, too. Then they do a scratch test with the altered tomato. Since the gene-spliced tomato is identical to the ordinary tomato except for the gene and it's resultant structure, if they test the same, then the anti-freezing gene doesn't produce allergens.
Note that the FDA requires all foods and drugs it has tested to publish
every single reaction during testing. Every single one. If only one person has a problem during clinical, even if the problem has absolutely nothing to do with the product, they food or drug companies are legally required to print it on the packaging and commercials of the product. Ever seen those commercials for drugs where they say "Side effects may include..." then list a string of medical problems? Say, nausea. It's because some people during the clinic trials reported that they were nauseous that day, which many times has nothing to do with the product. The fact that gene-spliced tomatoes
don't have warnings for people with fish allergies and they they've been through clinical trials is proof that a connection doesn't exist, since many, many heads would roll if they failed to report and label the connection.