Food Notes & Tousim 01/11/2010

Genes and allergens. Allergy to Gmo?

The challenge to uncertainties, lack of confidence and human prejudice. After last week intervention, Paola Cerana writes again of a hot topic. The transgenic research? It has opened a door wide to a marvelous, invisible universe

The criticism against genetically modified food often evokes the fear of new allergies, that would leave us unprepared to face them. From the "itching" to the catastrophe, the step is portrayed as immediate! What is the true relationship between GMO and allergies?

It is well known that genes are fragments of DNA which instructs cells on the production of proteins. Several allergens are proteins, so the genetic manipulation can actually transfer “good” as well as “evil” information, such as an allergen present in the transferred molecule.

For instance, when scientists tried to improve the quality of soy seeds, by inserting a gene from the Brazilian nut, people who are allergic to nuts developed an allergy to soy seeds as well. Obviously this type of soy, initially destined to animal feeding only, was never introduced onto the market. Many nutritionists, environmentalists, animal rights, formed an alliance against GMOs, based upon the idea that genetic manipulations cannot prevent the risk of create a chain of allergies.

Truth is, scientists well know which proteins can eventually trigger allergic reactions. Two criteria appear to be discriminant: first, if a protein is easily soluble, then it can be a potential allergen, as it is more likely for it to go through the intestinal walls into the circulation, thus reacting with immune system cells. The standardized tests that reproduce the functioning of the digestive tract show it very well, so that these proteins have been banned from any genetic manipulation. In light of these results, the specific ammino-acidic sequences inside proteins have been isolated and listed in very detailed databases, that allow scientists to compare transgenic and naturally existing proteins.
Second, the molecular weight of proteins can reveal its allergenic potential. Most of allergens, have a molecular weight between 10000 and 40000 dalton (one dalton is one twelfth of the mass of an carbon-12 atom and it is approximately equivalent to the mass of a hydrogen atom). Therefore, the size and weight of the molecules are also an important guide for scientists, and can help them in the gene experimentation, preventing from costly mistakes.

The interest for these topics is ever greater, and now the proteins involved in the gene manipulations have become the object of studies, which are even more detailed than studies on natural proteins. The only sure thing on the relationship between GMOs and allergies, to date, is that no human being has developed any allergy to any of the proteins present in the genetically modified food on the market. Still the scientific research is constantly in search for solutions and maybe in this very same moment some scientists are debating the current state of the art on the topic. This is science, the irreversible process that, moved by the fire of knowledge, pushes for discovering ever more.

This topic is extremely interesting and fascinating, and this is the first time that I take on a relatively unknown territory for me, such as chemistry, hoping that my profane, but not allergenic, curiosity, may induce ever more detailed and constructive observations.

The transgenic research opened wide a door on a marvelous, invisible, infinitely little universe that moves, evolves and relates to the infinitely large universe surrounding us. An equally large microcosm, able to trigger extraordinary macroscopic effects, which appear ever less mysterious and fearful, thanks to the passion of those who study the language and explain the laws, accepting every day with courage the challenge, the lack of confidence and the human prejudice.